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Home My WebLink AboutLUA16-000963_Report 1Parametrix ENGINEERING. PLANNING. ENVIRONMENTAL SCIENCES 'JI/II/I fif;w»rs ....... 719 21\D i'WE:.NUE, $Lill E 200 I SE.AHLI:, WA 98104 ! P 206.394.3700 MEMORANDUM DATE: TO: FROM: SUBJECT: CC: December 6, 2016 Mathew Herrera Katheryn Seckel Steep Slope Exemption Request/ Changed Shoreline Mitigation Strategy Proposal Jason Rich, King County Parks Jenny Bailey, Parametrix PROJECT NUMBER: 554-1521-084 PROJECT NAME: Lake to Sound Trail Segment A This memorandum addresses two remaining elements for the City of Renton's approval regarding the Lake to Sound Trail Project: 1) a Critical Areas Exemption for protected slope, and 2) approval for relocation of mitigation that was previously approved by the hearings examiner (Shoreline Substantial Development Permit, Shoreline Conditional Use Permit and Shoreline Variance, file number LUA15-000257 ECF, SSDP, S-CUP, S-V). Attachment A includes a list of items submitted on behalf of the previous permit submittal -for purposes of this request, the City of Renton waived the requirement to resubmit the permit materials listed. The following discusses each of these permit approval items individually. Critical Areas Exemption (for protected slope) It was requested by the City of Renton that we file the attached (Attachment B) Critical Areas Exemption Short Form to comply with the Hearing's Examiners conditions for the above referenced shoreline permit. And because we already submitted a comprehensive package with the original permit application, it was requested that in lieu of resubmitting the entire permit package, we instead provide a detailed narrative of the work that would occur in the steep slope and identify where in the Geotechnical Report the bridge foundation is analyzed in order to expedite the exemption. The following is a detailed narrative of the work to be performed in the protected slope. For your reference, we have provided the final Geotechnical Report with this memorandum. A prefabricated steel girder pedestrian bridge, approximately 110 feet long and 12feet wide, will be installed to allow trail users to cross the Black River separately from vehicle traffic. The bridge wi/1 be located about 150 feet east of the existing Monster Road bridge. The contractor will construct the foundation system, then hoist the bridge with a crane to place it on the foundation. The crane will operate from the level area above the bank crest. As described in Sections 3.3 and 4 of the Geotechnical Report, substrates in the vicinity of the bridge are relatively deep, liquefiable soils that are prone to settlement and lateral spreading during a seismic event. Based on these soils and the results of the slope stability analysis presented in Section 4.2 of the Geotechnical Report, ground improvements wi/1 be necessary to improve seismic stability and to prevent undue lateral pressure on the bridge foundation. The method to be employed is wet soil mixing, also known as the deep mixing method. This ground improvement technique improves weak soils by mechanically mixing them with cementitious binder slurry. A powerful drill constructs columns of stable soil by advancing an auger with radial mixing paddles located near the bottom of the drill string. The binder slurry is pumped to the tool as it advances; additional soil mixing is achieved as the tool is withdrawn. December 6, 2016 Page 2 of 7 The deep mixing method creates columns of stabilized soil upon which the bridge foundations can be constructed. A total of approximately 63 soil columns will be created in this manner, stabilizing an approximately 16-foot by 37-foot area on the south side of the river and an approximately 16-foot by 30-foot area on the north side of the river. Each column will be approximately 4 feet in diameter and will extend 30 to 40 feet below existing grade. Construction machinery that will be used includes trucks, backhoes, a trackhoe, compressors, pumps, a drill rig (for wet soil mixing), and a crane for bridge placement. All above-ground elements of the bridge will be situated upslope of the ordinary high water mark (OHWM}. Mitigation Relocation The project design has progressed since the 60-percent plans were submitted with the shoreline permit applications. During that process, the proposed location of several Buffer Vegetation Conservation Areas (BVCAs) have changed due to property and access constraints (see Attachment C). Specifically: • King County cannot construct and maintain the BVCA originally envisioned within the property owned by a railroad company (BCV2; Station 8+00 to 11+00). The railroad will allow only an easement for the trail itself. • The County also cannot construct or maintain a portion of a BCVA that would obstruct the existing access road to the King County-operated pump station (BCVl; Station 105+00 to 107+00). These two areas total approximately 15,125 square feet. It is important to note that King County has identified equivalent areas in which to construct and maintain BCV As that are in the vicinity of the originally proposed areas. The areas from east to west: • East and west of the proposed pedestrian bridge (Station 17+00), the banks on both sides of the Black River, which we are referring to as BVC4. • East of the proposed pedestrian bridge, which we are referring to as BVC3. • North of the Black River between the pump station access road and the river, within BCV2. Under the approved permit, we proposed 42,741 square feet of BVCA. We are now proposing slightly more BVCA for a total of 43,050 square feet. The new areas of proposed mitigation are commensurate, if not of higher value to the area we removed under BVC2. We thank you for your consideration of these remaining permitting requirements. Please Jenny Bailey, Parametrix, at (206) 394-3656 if you have questions. ' Attachment A Previous Permit Submittal List Renton Lake to Sound Regional Trail -Segment Proposal Submittal Requirements Item# Item 1. Pre-Application Meeting Summary: 2. Waiver Form: 3. Plat Certificate or Title Report: (Submitted on CD) 4. Land Use Permit Master Application Form: 5. Environmental Checklist: 6. Project Narrative: Conditional Use Permit Justification: Variance Justification None Draft Legal Documents: 7. Construction Mitigation Description: Fees: Waiver Density Worksheet: 8. Full Size 60% Plan Set Neighborhood Detail Map: (Part of Color Maps) Site Plan: (Part of Color Maps) Grading Plan, Conceptual: (Part of 60% Plan set, Sheets 9-17): Landscape Plan, Conceptual: (Part of Color Maps): Waiver Architectural Elevations: Waiver Floor Plans: Topography Map (Part of Color Maps): Tree Cutting/Land Clearing (Tree Inventory) Plan: (Part of 60% Plan set, Sheets 9-17, trees with Note 14) 9. Tree Retention Worksheet: 10. Wetland Assessment (Critical Area Report): 11. Standard Stream or Lake Study: 12. Habitat Data Report (Veg & Wildlife}: Flood Hazard Data (Part of TIR): Utilities Plan, Generalized {sewer, water, stormwater, transportation improvements} (Part of 60% Plan Set): 13. Geotechnical Report (Draft}: Drainage Control Plan (Part of 60% Plan Set): 14. Drainage Report (TIR): Traffic Study: Include Parking Analysis (Included in #6. Project Narrative Section 2.6.1) Waived Urban Design Regulation Analysis Photographs of Property 15. Plan Reductions: II W' 1111" (11 x 17) legible reduction of each full size plan sheet 16. Colored Maps for Display # of Copies Submittal 5 5 3 12 12 12 None 5 $8,240 Waiver 12 Waiver Waiver 4 2 12 12 12 5 4 4 Waived Optional 1 1 Attachment B Critical Exemption Form CRITICAL AREAS EXEMPTION Applicant Name King County Parks, Jason Rich Parcel Number (FOR SEPA EXEMPT ACTIVITIES) Planning Division 1055 South Grady Way-Renton, WA 98057 Phone: 425-430-7200 Fax: 425-430-7231 Project Name Lake to Sound Trail Segment A Project Address Phone Number (206) 477-4582 722950-0281,377920-0090 The pedestrian bridge crossing of the Black River, for which this critical area exemption pertains, is at 550 Monster Rd SW. Brief Description of Project King County, together with the cities of Renton and Tukwila, the Washington State Department of Transportation (WSDOT), and the Federal Highway Administration (FHWA), is proposing to develop a 1.2-mile segment of what will ultimately be the 16-mlle Lake to Sound Trail. The 1.2-mlle segment is referred to as Segment A of the Lake to Sound Trail, and is also commonly referred to as the Two Rivers Trail. Segment A extends from Naches Avenue SW, parallel to the railroad tracks north of the Black River Riparian Forest, across the Black River on a new non-motorized bridge and under two railroad bridges to the Green River Trail at the north end of the Starfire Sports Complex In Fort Dent Park. Type of Critical Area t8) Work Occurs in D Work Occurs in Protected Slope Critical Area Buffer PURPOSE: Exempt activities provided with a letter of exemption from the Development Services Administrator may intrude into a critical area or required buffer (Subject to any conditions or requirements provided by the Administrator). APPLICABILITY OF EXEMPTIONS: The following is a general list of activities that may be exempt from the critical areas regulations. More specific descriptions of the activities are contained in the Critical Areas Regulations. Some of the listed activities may not be exempt in certain critical areas. The Planning Division will evaluate you request according to the City of Renton Critical Areas Regulations in RMC 4-3- 050C, J, L, and N. I AM REQUESTING A CRmCAL AREAS EXEMPTION FOR ONE OR MORE OF THE FOLLOWING ACTIVITIES: D Conservation, Enhancement, and Related Activities: • Conservation or preservation of soil, water, vegetation, fish, and other wildlife • Enhancement activities as defined in chapter 4-11 RMC D; • Any critical area, buffer restoration, or other mitigation activities that have been approved by the City U:\P$0\Projects\Clients\1S21-KingCo\SS4-1S2l-0$4 L25T\02WBS\PH..A 2 RNers\Shoreline CUP\Rentpn\CrttiulAreasE11;t?mpl20ltS\AttachA_CAExemptShortFrm.dooc D Research and Site Investigation: • Nondestructive education and research • Site investigative work necessary for land use application submlttals such as surveys, soil logs, etc. 0 Agricultural, Harvesting, and Vegetation Management: • Harvesting wild foods • Existing/Ongoing agricultural activities 1 • Removal of dead, terminally diseased, damaged, or dangerous ground cover or hazardous trees which have been certified as such by a forester, registered landscape architect, or certified arborist D Surface Water Alteration: • New surface water discharges provided the discharge meets the requirements of the Storm and Surface Water Drainage Regulations '2 3 • New or modified regional storm water facilities 1 2 3 • Flood hazard reduction 1 3 4 6 [gj Roads, Parks, Public and Private Utilities: • Relocation of Existing Utilities out of Critical Area and Buffer • Maintenance, operation, and repair of existing parks, trails, roads, facilities, and utilities 1 2 • Installation, construction, replacement, or operation of utilities, traffic control, and walkways within existing improved right.if-way or easement 1 2 • Modification of existing utilities and streets by 10% or less 12 s • Management and essential tree removal for public or private utilities, roads and public parks 1 D Wetland Disturbance, Modification, and Removal: • Any activity in small Category 3 wetlands ' 2 3 • s • Temporary disturbances of a wetland due to construction activities that do not include permanent filling 1 2 3 s D Maintenance and Construction for Existing Uses and Facilities: • Remodeling, replacing, or removing existing structures 1 2 • Normal and routine maintenance and repair of any existing public or private uses and facilities where no alteration ofthe critical area and required buffer or additional fill materials will be placed 1 2 • Construction activity connected with an existing single family residence or garage, provided that no portion of the new work occurs closer to the critical area or required buffers than the existing structure and/or the developed area of the site 1 2 • Existing activities which have not been changed, expanded or altered provided they comply with the applicable requirements of chapter 4-10 RMC 1 D Emergency Activities: • Removal of trees or ground cover by a City department, agency, public, or private utility in an emergency situation U:\PSO\Projeru\Oieot>\1S2l·kin1Co\5~-1S21-{)84 L2Sl'\02W8S\PH·A 2 Rlver,\Sh0<eline CUP\Renton\Crttlc.ilAreasbempt2016\AttKhA_CAEJ:emptShortFrm,doo: • Public interest emergency use, storage, and handling of hazardous materials by governmental organizations in an Aquifer Protection Area ADDITIONAL PERMITS: Additional permits from other agencies may be required. It is the applicant's responsibility to obtain these other approvals. Information regarding these other requirements may be found at http://apps.ecy.wa.gov/opas/ U:\PSO\Projects\Clients\lS2l,1Qn£Co\SS4-1Sl1-084 L2ST\02W8S\PH-A 2 Rjve-n.\Shorehne CUP\Renton\Crilic.alAre•sbempl2016\A.ttachA._CAExemptSt:iortfrm.docx D Exemption Granted C.E. "Chip" Vincent, Planning Director Planning Division Conditions of Approval: 'Exemption does not apply in Aquifer Protection Areos 'Exemption does not apply In Flood Hozard Areas 'Exemption does not apply in Geologic Hozard Areas 4 Exemption does not apply in Habilal Conservation Areas 'Exemption does not apply In Streams and Lakes: Class 2 to 4 'Exemption does not apply in Wetlands U:\PSO\Pro}ects\Oients.\l52l·K1ngCo\SS4-lS21-084 l..2Sl\02WBS\PH~A 2 Rivtts\Shoreline CUP\Renton\CnticalAreasbemptl016\Attic:hA_C6,£xempt5hortfrm.docx D Exemption Denied Date Attachment C Mitigation Plan Changes 0 ** GREEN RNER .-----01-1~------ /.,,,,,--------------------0 * j 1 ~/-i **oO * ~ 0 0 * O * ~ 0 0 .: * * 0 * ~ \ f \~ GREEN RIVER TRIJL 1 ~ . i! CONSTRUCTION NOTES : 8 PLANTING AREA CLEARING AND GRUBBING STAKE OR FLAG PROPOSED PLANTNG AREA LIMITS FOR >PPROVAL OF PROJEC T REPRESENTATM: PRIOR TO STARTING CLEARING WORK. CLEAR AND GRUB ROOTS AN D RE MOVE: ANO DISPOSE or ALL UNWANTED VEGETATION IN THIS PLANTING Afl.EA LEAVE SOIL IN PLACE. SEE SPECIFICATION FOR UST or UNWANTED VEGETATION. lo\ COUPOST. PLACE 3· LAYER COMPOST OVER THE ENTIRE \_V SURFACE OF THIS PLANTING AREA. 0 WOOD CHIP MULCH. PLACE 3" LAYER WOOD CHIP MULCH. GENERAL NOTES: 1. SEE SHEET MP6 AND FOR PLANTING DETAJLS AN D REQUIREME NTS. 2. LOOSEN m Y SOILS IN PLANTNG AREAS COMPACTED BY CONSTRUCTION ACTMTI ES BY RIPPING OR TILLING THE AREA TO A DEPTH or 2~" '\.; ~ ,., , ·, '-""'-. ,w I ,~ """ "' I w '•" ' ~ "' '"o' '--~--w -~ -......___ ~ c-----<:-z ·-~ --' ,- ----~ -~-LINE ~--' TREE REPLACEMENT CALCULATION FOR 3. PLANTING Afl.EA LIMITS ANO INTERPLANTING LOCATIONS SHALL BE STAKED IN THE FIELD m o APPROVED BY PROJECT REPRESENTATM: PRIOR TO PLANTING. ~ ~ .; /; 1 ¥ I" i / ~ ' i -:. ,'! -: 0 ~ ~ ~ J ~ ~ ~ ' :;, i ~ fi ~ ] __ ,_ = -c.-= J:C SIGNIFICANT TREES --o-:...c---' ,,,,--C ~>~----4'----X ,_ ----------------___ , ___ ---/ -----------------------_ _,_ ____ ;::= <( / --•-------=-'Ci'-=--,/' I I PLAN ® SCALE IN FEET ~ FORT DENT PARK DIAUETER' or TREE NUMBER or RE MOVED ('MEASURED AT HEIGHT or 4 .5 FEET REPLACEMENT FR OM THE GROUND) TREES REQU IRED 4-6 INCHES (SINGLE TRUNK); 2 INCHES (ANY TRUN K or A 3 MULTI -TRUNK TREE) OVER 6-8 INCHES 4 OVER 8 -20 INCHES 6 OVER 20 INCHES 8 TOTAL 0 20 40 "' I ~ "-"' / __J !Q ~ -"-, -'1•----, ~---I "---' - 0 '-, 8LAClrllN£R / _ -----L----'-, ------ ~ 0 '-, ,,._____ ----0 * ------4-~ "! • ......__ / '"""~-* . ------·----~--,,,,_ .. .,, °' 0 --',j 4 --...... ' -4 " ~-· ~ ~ ~ * ............. ........_-.Ql;Qv.AL_-----7-' -----~ -.-.,,c-=-~=---·-:__ - _)* o o * o * o~---~? --:::=---..::._ -~-. . ' 0 <i' \. ~.-aa - ' / ---=-------=-----I P.Ll .----------- * , . ----;,:.,------=-•~ " ,/ ------·-· 0 ' * 0 ~--_!c-=-L. ~~-, ------c;,-,,--<"" * ----·-----.-J!--/----~~,-.:,llv_ -1\ ~ C--,,,c,7° ~·""·!, -~ ----::::,,:-::.,, ~ 0 ~i\/ / • ~ ~ -• / --=,-----,---? > __..,-' ----•--' ,.,.,; , ~----,, * , -' - / . - " FORT DENT PARK I I I ; I NUMBER or TREES REM OVED 1 2 5 2 10 % : ~ ; ~ 0 DAT£ leY I CESI CN(O -,NSON ~, 61•Moos I I b v.i Q_ ~----1------------+---+---------, ORA.wt. J. SWENSON CH£CKED I I I OVEOKUTA J I 0. Kl AP P!< " I ------1 ' ------I -l' ___________ _ --------~ ~"'°' II p •~"'"'" SW SCA --• LANDs~.f~rsIRcHITECT . I R IVER TRA IL TO NACHES AVE <O @>Ii:/'@ " "'" ,~ .... ,,:;,c,,-.1 A,, N 656 O:W:'-C "; , ,,.,.~, ""' ::::~;:::.:.:~ ~u ENGINEERING PLANNING ENVIRONMENTAL K IE NCES LAKE TO SOUND TRAIL SEGMENT A PROJECT NAME NUM BER or TRE ES TO REPLACE ONSITE 3 8 30 , 6 57 ~. ALL PLANTS TO BE SAVED mo PROTECTED WITHIN CLEARING AND GRUBBING Afl.EAS WILL BE FLAGG ED BY PROJECT RE PRESENTATIVE. NOTIF'I' ENGINEER 5 DAYS PRIOR TO START or CLEARING ACTMTY. USE ON LY HAND TOOLS AND METHODS WHEN WORKING INSIDE THE ORIPLINE AREA or EXISTING TREES AND SHRUBS 5 . PLANT DEBRIS FROM REMOVAL OF INVASM: PLANTS OR PRUN ING SHALL BE RE MOVED FROM THE SITE AN O DISPOSED or PROPERLY. LEGEND: --------URBm CONSERVANCY BUFFER WETLAND BOUNDARY -------ORDINARY HIGH WATERLINE • ~-----· DESIRABLE VEGETATION EDGE EXISTING TREES ~x·~~--, ' ' . EXISTING TREES TO BE REMOVED ' . -' ' HABITAT LOG . SEE SHEET MP-6 * BRUSHPILE. SEE SHEET MP-6 TILL />REA 10 24" DEPTH PLANTING QUANTITY TAB -THIS SHEET ONLY- .:, 1Mi;.vl ITE M I OUANTIT)' TREE REPLACEMENT PLANTNG I ~~ NATM: CONIFER TR EES -SPACE 15 0.C . LA: ~II'( I 10 41" W N I 14 oll KA ,, o U~t I 10 1' ~ NATIVE DECIDUOUS TREES -SPACE 15 0 .C. "lv-LtAt MReo I 14 I'<. J ... m:r.hl N ASH 9 95% REVIEW SUB MITT AL NOT FOR CONS TRUCT IO N CRA'll1NC N O 48 OF 59 MITIGATION PLAN ABBREVIATIONS: ACP ASPHN.T CONCRCTE PAVEMENT PC BOC BACK OF CURS PT BOW BACK OF SIDEWALK P/L BP BEGIN PROFILE PRC BVCE BEGIN VERTICAL CURVE ELEVATION PUD BVCS BEGIN VERTICAL CURVE STATION PV1 CB CATCH BAS IN R C&G CURB AND GUTTER RT C/L CENTERLINE ROW o r R/W CONC CONCRCTE SD CONST CONSTRUCTION SDMH CMP CORRUGATED METAL PIPE ss COR CITY OF RENTON STA CP CONCRETE PIPE TOA CSTC CRUSHED SURFACING TO P COURSE TEL DIA DIAMETER TESC DI, DIP DUCTILE IRON PIPE lYP E EAST, EASTING VC EOA EDGE OF ASPHALT VERT EOG EDGE OF GRAVEL w EOP "' EDGE OF PAVEMENT ws ~ EP END PRO Fll£ WSDOT ;;; ] EVCE END VERTICAL CURB ELEVATION t EVCS EN D VERTICAL CURB STATION ~ " EX, EXIST EXISTING i FOC FACE OF CURB li : "' FL FLANGE, FLOWUNE ~ G GAS D GB GRADE BREAK D 1 t HMA HOT MIX ASPHALT ~ HORIZ HORIZONTAL 0 ,t ID INDENTI FICATION IE INVERT ELEVATION 1 KC KING COUNTY ~ LF LINEAR FEET ii LP LOW POINT '.;, LT LEFT "' j ME MATCH EXISTING ~ MIN MINIMUM 8 < ~ MON MONUMENT y ~ N NORTH, NORTHING C ~ N.I.C. NOT IN CONTRACT ~ NO. NUMBER 0 I ~ NST NOT STEEPER THAN j OHWM ORDINARY HIGH WATER MARK 1 ¥ :j ~ j 0 " i ! ;; CITY OF RENTON LUA 15-00257 SSDP, S-CUP, AND S-V !1£ /:::, I RE\15'0NS lo•TE l•v I D(S,f'b°VORAJ< < .. DRAWN M. MILLER Oi[O<W 0 . KIKUTA APPROVED POINT OF CURVE POINT OF TANGENT PROPERlY LIN E POINT OF REVERSE CURVATURE PUBLI C UTILllY DISTRICT POINT OF VERTICAL INTERSECTION RADIU S RIGKT RIGKT-OF-WAY STORM DRAIN STOR MWATER MANHOLE SANITARY SEWER STATION THRESHOLD DISCHARGE AREA TELEPHONE TEIAPORARY EROSION AND SEDIMENT CONTROL lYPICAL VERTICAL CURVE VERTICAL WATER WATER SERVICE WASHINGTON STATE DEPARTMENT OF TRANSPORTATION O N E INCH AT F U L L SCAL E . IF N OT, SCALE ACCORDING L Y 03 --INDEX TO DRAWINGS DWGNO. SHTNO. SHEET TITLE GENERAL 1 G1 COVER SHEET 2 G2 ABBREVIATIONS AND SH EET UST 3 G3 LEGEND 4 G4 SURVEY CONTROL PLAN 5 G5 SURVEY CONTROL PLAN 6 G6 A-LINE CONSTRUCTI ON BASELINE CONTIROL 7 G7 C-UNE CONSTRUCTION BASELIN E CONTROL 8 G8 B-LINE CONSTRUCTION BASELINE CONTROL SITE PREPARATION 9 TESCl CLEARING, GRADING AND TESC PLAN 10 TESC2 CLEARING, GRADING AND TESC PLAN 11 TESC 3 CLEARING. GRADING AND TESC PLAN 12 TESC 4 CLEARING, GRADING AN D TESC PLAN 13 TESC5 CLEARING, GRADING AND TESC PLAN 14 TESC6 CLEARING, GRADING AN D TESC PLAN 15 TESC7 CLEARING. GRADING AND TESC PLAN 16 TESC8 CLEAR ING , GRADING AND TESC PLAN 17 TESC9 CLEARING , GRADING AND TESC PLAN TYPICAL SECTIONS 18 CS 1 TYP ICAL CROSS SECTIONS PLAN & PROFILE 19 Cl PLAN AND PROFll£ 20 C2 PLAN AND PROFll£ 21 C3 PLAN AND PROFlLE 22 C4 PLAN AND PROFll£ 23 C5 INTERSECTION PLAN 24 C6 PLAN AND PR0Fl l£ 25 C7 PLAN AND PROFILE 26 CB PLAN AND PROFll£ 27 C9 PLAN AND PROFll£ 28 c,o PLAN AND PROFll£ 29 C11 PLAN AND PROFIUE 30 C12 PLAN AND PROFILE 31 C13 PLAN AND PROFILE 32 Cl 4 PLAN AND PROFll£ 33 C15 SIGN SCHEDUUE AND GRADING DETAI L 34 C16 GRADING PLAN STORM DRAINAGE 35 SDl CULVERT DETAILS WALL PROFILES 36 WP1 GRAVllY BLOCK WALL PROFlUES DETAILS 37 0 1 DETAILS 38 02 DETAILS 39 D3 DETAILS 40 D4 DETAILS SIGNALIZATION 41 TSl SIGNAL PLAN 42 TS2 SIGNAL WIRING DIAGRAM 43 TS3 SIGNAL POL£ SCHEDUUE AND DETAI LS STRUCTURAL 44 S1 BRIDGE PLAN ANO ELEVATION 45 S2 BRIDGE FOUNDATION LAYOUT 46 S3 PEDESTRIAN BRIDGE PIERS 1 AND 2 47 S4 BAIRLIST MITIGATION 48 MPl MITIGATION PLAN 49 MP2 MITIGATION PLAN 50 MP 3 MITIGATION PLAN 51 MP4 MITIGATION PLAN 52 MPS MITIGATION PLAN 53 MP 6 MITIGATION PLAN 54 MP7 MITIGATION PLANTING DETAILS 55 MPB MITIGATION NOTES TEMPORARY TRAFFIIC CONTROL 56 TC1 TRAIFFIC CONTROL PLAN 57 TC2 TRAIFFJC CONTROL PLAN 58 TC3 TRAmc CONTIROL PLAN 59 TC4 TRAIFFIC CONTROL PLAN RIGHT-OF-WAY 60 RW 1 RIGKT OF WAY PLAN 61 RW2 RIGKT OF WAY PLAN 62 RW3 RIGKT OF WAY PLAN 63 RW4 RIGHT OF WAY PLAN 64 RW5 RIGKT OF WAY PLAN 65 RW6 RIGHT OF WAY PLAN PRO...CCT NAME ENGIHEE "-ING. Pl.ANNING . EN IIIMONMENTAL 5(:IEHCll!:S LAKE TO SOUND TRAIL SEGMENT A GREEN RIVER TRA IL TO N ACHES AVE SVV 100% REVIEW SUBMITTAL FOR RENTON NOT FOR CONS TRUCTION ABBREVIATIONS AND SHEET LIST OR AWl"IG NO. 2 OF 65 G2 Puget Soun d ,- ' Lake Washington -... ~~ J, PORTION OF SECTIONS 13, 14, 23, AND 24 TOWNSHIP 23 NORTH, RANGE 4 EAST&. Lake to Sound Trail Segment A Green River Trail to Naches Avenue SW King County, Washington Contract No. C01119C17 Federal Aid No . CM-2017(110) 4f iJ'1"i UNIN.CORPORATED ', I ~ l I KING ' St,i,, l/~~. ~OUNTY / {a/11 '\~ I . Sf. V' -,,~ ---I OtJhi \ ....... I --, r -rt ~ ~~ \ a:;i __ ,. __ , " 'r-~""' I I I '· \ END I \ ~\ i \,, .., Sunset ?'~, i ~ \._,,,,,1 I \ ~ PROJECT '900'"' t ~\-.JO ~' ~ '\ ') f~ : -::~~-I • '°)\"(\ ~\ \ I ]----------".:::!... ---·-<:.'t4 Burien .! J LOCATION MAP NOT TO SCALE CITY OF RENTON LUA15-00257 SSDP , S-CUP, AND S-V 6 1 REYIS<OOS BY OCSICNEO J . DVORAK DAT[ t( 6 '% ~ ~ tO J' I I I I IORA"•N 1···--··-----------·1 : : • . : M MI LLER _ h na,, ,....,,..,.,,..,,,..,--------t t---+---------------+-----1---, CHE~~E~IKU TA ..._PPROVEO --~ ~ SW 7TH ST cl!; 3' V> ~ ~ j V> ~ 0 V) ;;: !,!;' '( ~ J s\N c;ra.oj "-J a'} 0 _., --__ .. ~\ . ~--·· -- . ~ - 1-405 ~ VICINITY MAP NOT TO SCALE PRO...CCT NAM[ LAKE TO SO UND TRAIL E.NGiNEEllt!NG.PLJINHINC.fNWONMfNlAlSCIENCH I I SEGMENT A GREEN RIVER TRAIL TO NACHES AVE SW JI CONTACT INFORMATION : APPLI CANT: KING COUNTY PARKS AND RECREATION 201 S. JACKS ON , 7TH FLOOR SEATTLE, WA 98104 ATTN : JASON RIC H (206) 427-8576 ENGINEER: PARAMETRIX, INC . 719 2ND AVENUE , SUITE 200 SEAffiE, WA 98104 ATTN : JENNIFER DVORAK (253) 604-67 50 SURVEYOR: PARAMETRIX, INC. 719 2ND AVENUE. SUITE 200 SEATTLE, WA 98 10 4 ATTN: BOB PUSEY (360 ) 850-5342 ~ 100% REVIEW SUBMITTAL FOR RENTON NOT FOR CONSTRUCTION COVER SHEET OR..._'NI NG NO. 1 OF 65 G1 t ; ,? ~ g ~ ~ ~ ~ / ~ 1 :!. I ~ ~ ® I rt" SCALE IN FEET I $~ ~=176 607.11 O 100 · 20 0· \,. E=1290388 .76 ~ ELV=35.01 Q ~ BEGIN C-LINE FOUND I.ION IN CASE I ...I STA201+00.00 SW13-23-04 IW "-SE 14-23-04 KC p""[l NO 002 \en BEGIN PROJECT """""° N•1764n.49 _ -r STA 1+00 .00A-l.lNE "-I I 0 ':.,_,"",;:'° I E-1290501 99 --------lli I ~ : ,LCss!l-"""~---/ ELV=34.95 -------Cl) ,c N !()l <O 11195003(,<) , , _ --,-• --' ---l.0&11< ---· -+ I / ""° '°"" -t-; ;""'°'., • . ,,---... --BEGIN B-1..INE --• 11 00 --' I~ t/ 'l!ACTJ<ROITON""""""':,S --~: ~= :,,PAA(,[l,,;~i '" --~~--10CM)0 STA99+94 .19 ~ENDA-LINE ---------~ -~ \:i ,' ~r:fil"--::-t---8~1~S(7-~0:' co ------.,, ---~-::------,c P..:U~IJlJOHJ20 STA 17+76. 45 ----------_......--N=~~7033 .12 :::c +00 A-LINE 4+00 -----:t7 ------:..::~ ------..--------'--:!::::-__~~ ----------------~/ E=1291310.30 (.) I---'-'--=-=-; ----+--,c PA,c[l "' I "" -""'-.. ,, PAAtn "' >,)'¥17 ELV=:I0.68 . 11:; 2Jii->• 9001 / "'-• ..---/ 0;,'~i:;,. ,.~-' SET REBAR NO CM' / , .... Ort c, 100,l.' KC P>RCEL HO. "-'),. S kt P"-CU t<J :E I ,, PIK,,"° "''°'~ _Y ,<..,,_ ', ~ ,cs..oo __--,,,,200,,, ' \ "''""'"" "' I O• RS'"" HM. co ,,,..:_ ~-.., "fl F~ -..,,_, ____:.,_.+ -ctTY" "''"" / : "" ~ssu -ul'ffl<,/ -.. , , o...,;\ ---=---------------! /-~--"'< ~ ' -------., ,' / N-1761 25 6' t~, ... '1,, >' ~ • ""' I NE 23-23-04 -,. ' ' I ' I 901 1 ' -r.: ('... ~, :iJ.P.C[l MO .mnoo11g "-.. I -· ·,0_1.m,o,90M ~ ? h" "- \ [•1290276.6 1 CITY r; Ill<"-' , -<._ "Cb ~'It,';;~~, 72362 ' / \ CITY OF TUKWILA : ElV=27.80 "-~ ~,"' '··----N=176395.57 "'-I '--. FOUND 1-W BRASS DISK , "-...... ~-[=1290884.66 \ / I ~ / PUNCH 0.5' DOWN '-._ '"-,. ELV=26.59 , I "-..._ .oa;, ' SET ~L , I I, CITYOFRENTON '-~~ '"' J \ V , " p...:c, "° ,,,.sooi,, , ~v~ , '"'-\ : '-,.,:; COOHN P8 fll[ "'°'' ~ "-'- I ;· ~~C',: '-'y ~--"" ~ ENDC-1..INE "' ~~ "-~.ffa~"Oo""-'>< STA206+50.00 "' NW 24-23-04 ly~ ~s~-:'v "'-. '-~ ..... I ' ' I "'-;-----------------...... __ __ I SCM " em y I '°' 200' \ ,, ,_ • SW 1~23"4 o SE 13.2,_.. \).'~902C " -.. >• $/ -t1 ---------------------.-.. ______ /t " ----, .. ___ I :,: .---,--' ,_ ----........ g;' I ' 115'00 ~ -~ ----.,____ -·---.. • ~ C ' --+--~ I ' -...___,_ ~ <' " ® z --7' ---~ -·-· ...... _ C, m , " : -..__ _ ,~ · ..__ ,,_ I ' N-17735 1.98 ) ~, --""-l4J ~k1 ,_,,,,,.,.,, --~ ·--...., I A!(; m ,' ELV=22.73 / • ...::o..._.__l: '.. ~ , ·-...._ 4, ~' ·, I I ""-~ ·---.,~ ~ '" """' '° CII' • " -~ ...._ (,j <• "=·· m\ ""· / :,"l;':;;,. / "-· ~,~ , ,,_,, I /~ \ ,c PAAtrl NO. / / CITY (HfflDH / il: ~, I /,;';,";\,. ( 'I I ;t I I r·,. --~. I L_______ ' ' I I \ \ \ SUR VEY NOTES: 1. HORIZONTAL DATUM, BASIS OF MERIDIAN . GRID NORTH , WA SHINGTON COORDINATE SYSTEM, NORTH ZO NE, NAD83(9 1) HELD CITY OF REN TON MONU MENTS: HORI ZONTAL AND STATIONS 1333 AND 1854 2 . VERTICAL DATU M: NAVO 88 HELD CITY OF RE NTON BENCH MARKS B M#1 333 AND BM # 18 5 4 3. THIS MAP CORRECTLY REPRESENTS COND ITIONS AND FEATU RES E XISTING AT THE TIME OF THI S TOPOGRAPHY IN OCTOBER, 20 1 0 . 4. CONVENTIONAL AND GP S SURVEY EQU IP MENT WAS USED IN THE PERFORMANCE OF TH IS SURVEY . ALL EQU IPMENT IS MAI NTA INED IN CONFO RMANC E WITH CURRENT STATE STATUTE. ,; , '} u CITY OF RE N TON LUA15-00257 SSDP, S-CU P . AND S-V 100% REVIEW SUBMITTAL FOR RENTON NOT FOR CONSTRUCT ION ~ 6 REVISIONS OA TE BY O(SJG~[O i i ~ J. DVORAK OR.A \toN K. BRAATE N 0 CrECKED G05 ~ 0. KIKUTA PRO...CCT NAME EHGINl!:ffUNC, PLANNING . f.Nl/lft.ONW:NTA L $C~NC[$ LAKE TO SOUND TRAIL SEGMENT A ~ APPRQ\l[Q ==~ -w--I GRE EN RIVER TRAIL TO NACHES AVE SW I SURVEY CONTROL PLAN DRl.."'1<.lG NO 4 OF 65 G4 l ~ 0 0 1 ~ ~ NI Ji ii ,?_ J. J -;; ::, '.,- LEGE ND DESCRIPTION RaN LINE RAILROAD C/L PROPERTY LINE CITY BOUNDARY LINE EASEt.lE NT LINE FOUND MONUMENTS REBAR & CAP HUB & TACK PK NAIL PROPERTY CORNER STREAM BUFFER STREAM EDGE OF WATER WETLAND FLAG ORDINARY HIGH WATER t.l/\RK I 00-YEAR FLOODPLAIN BOUNDARY SURFACE FLOW DIRECTION DITCH LINE STORM DRAIN LINE CULVERT QUAR RY SPALL CATCH BASIN, TYPE 1 CATCH BASIN, TYPE 2 INLET PROTECTION SANITARY SEWER LINE SANITARY SEWER MN-IHOLE SANITARY SEWER VAULT CL£AN OUT CONTOURS MAJOR CONTOURS MINOR FlL TER FABRIC FENCE HIGH VISl81UTY FENCE Cl.EARING AND GRUBBING LIMITS Fll..L LINE CUT LINE SAWCUT LINE ASPHALT EDGE CONCRffi LINE CURB ANO GUTTER LINE EDGE OF PATCH EDGE OF GRAVEL JURISDICTIONAL DITCH ROCKERY CONCRETE BARRIER PROPOSED ~ • (a) @ © -----2----- -0 -0 -0 -0 -0- --0--00-00-oa -- -----r-----r-----r -----r- -----c-----c -----c-----c- I I I I I I I I I CITY OF RENTON LUA15-00257 SSDP, S-CUP, AND S-V ~ _yN_ ___ RAILROAD C/L_ ______ ELh_ _____ _ -··-··-··-··- • • ___ _JlliW.J!_ ~ 6 R[\11S:QNS DA 1[ B'r' OCSICNEO o.. J. DVORAK ONE INCH AT F U LL SCALE. DRAWN IF N OT, SCALE ACCORD INGLY n M. MILLER O CHECKED " 0. KIKUTA LEGEND DESCR IPT ION SPLIT RAIL FENCE LINE BARBWIRE FENCE LINE CHAIN LINK FENCE LINE HOG WIRE FENCE LINE WOOO GUARDRAIL GUY ANCHOR POWER POLE WITH LICHT FLOOD LIGHT UTILITY POLE PP W/ UG DROP PP W/ UG DROP & XMFR OVERHEAD POWER POWER POWER VAULT POWER TRAN SFORMER POWER MN-IHOLE POWER HANDHOLE POWER CABINET POWER RISER POWER METER SOLID LID J-BOX LUMINARE TELEPHONE VAULT TELEPHONE RISER TE1£PHONE MANHOLE TELEPHONE TV RISER TV FlBER OPTIC GAS VALVE GAS WATER LINE FIRE HYDRANT WATER METER WATER VN..\/f. WATER BLOW OFF VALl/f. WATER POST INDICATOR SPRINKLER HEAD RC T~90 IRRIGATION CONTROL VALVE PROPOS ED ~ --11---11---11-- a a a a o o u +--)( .... PRO.,CCT NAM[ [HGIHf!l'UNG. "l.ANN!NG f NVlll;OHMf:NT.ll $Cll!NCf S LEGE ND DESCRIPT ION TRAFFIC SICNAI. POLE W / LAMP TRAFF1C SIGNAL POLE TRAFFlC CONTROL LOOP (SO) TRAFFlC CONTROL CABINET PEDESTRIAN POLE MONITORING WELL SURFACE POST SIGN SKIP LANE LINE SOLID LANE LI NE FOG LINE LEFT ARROW STRAIGHT ARROW RIGHT ARROW MAJLBOX TREES ~ffiAND SYMBOL WET\AND BOUNDARY 1/f.GETATION RETAINING WALL RIP RAP ROCKERY HANDICAPPED SYMBOL WHEELCHAIR RAMP BUILDING LINE CONCRETE STAIR LINE WOOD STIJRWAY ASPHALT PATH CEMENT CONCRETE SIOEWIJLK ENGINEERED SOIL MIX LANDSCAPE AREA RAMP OIETECTABLE WARNI NG RESTORATION PLANTING AREA TEST PIT OR BORE HOLE LAKE TO SOUND TRAIL SEG MENT A ~ APPRO,~O -~-,-I I GREEN RIVER TRAIL TO NACHES AVE SW I I PRO POSED ~ . ~ ._ < '· :1 ", I C:=J C:=J C=:J C:=J !illillillilll c=J .t. OR .t. TP-f BH-f 100% REVIEW SUBMITTAL FOR RENTON NOT FOR CONSTRUCTION I C>R.A.WNC NO. 3 OF 65 LEGEND G3 "' ~ .. z ~ l i ~ : < 0 ' .. i " a) ~ 0 i!' / i' ;, ~ I . I ~ ~ ~ § ~ ~ ' ~ :'.?- i ~ ~ ~ f t e ~ ~ -- 7" ~ -- I ______ ... _ _.-- . ----~IF\ 7K .. ~ 71<" /\ 71\7'~~~' -------------- ·---"'" ----------------WETIA -----'------------------------------- / '"-,, "-, '"-, '"-, '"-,, "-,, "-, '"-, '" ~ ', SCALE IN FE IT 0 20 40 STATE OF wCi ~~~sG[8N O N E INCH AT F ULL SCALE. IF N O T , SCALE ACCOR.DINGL Y ,u r ~ 6 REIIISIONS OAT( EY DESIGNED I I J . SWENSON LANDSCAPE ARCHITECT ORA'Nf',.I J . SWEN SON CHEg"E~IKUTA I ~a=~·••w ,cn •v'-W~~m, I AF=PN QV[Q --------- was on area dedicated to pump station access . ~l,.-w cJ, ---------~ -----------------------. Vegetation Conservation Areas (BVC3 and BVC2) --------- Total BVCA area proposed at 60% design = 42,741 SF Revised total BVCA area = 43,050 SF f:PK.IN EEll!N G ~LANNrNQ ENVIRONMENTAL SC IENCES PRQJ[Ci NAM[ LAKE TO SOUND TRAIL S EGMENT A GREEN RIVER TRAIL TO NACHES AVE SW CONSTRUCTION NOTES: (,\ MITIGATION Ci.£ARING AND GRUBBING. STAKE OR fl.AG \..:_,J PROPOSED PLANTING Ml.EA LIMITS FOR APPROVAL OF PROJ ECT REPRESENTATIVE PRIOR TO STARTING CLJEARI NG WORK. CL.EAR AND GRUB ROOTS AND REMOVE AN D DISPOSE OF All UNWAN TED VEGETATION IN THIS PlANTING AAEA LEAVE SOIL IN PLACE. SEE SPECIFICATION FOR UST OF UN WANTED VEGETATION. r;;\ COMPOST PLAC E 3• LAYER COMPOST OVER THE ENTIRE \::.J SURFACE or THIS PLANTING AAEA. f,\ WOOD CHIP MULCH. PLACE J" LAYER WOOD CHIP MULCH \.::.) OVER THE ENTIRE SURFACE OF THIS PLANTING AAEA. GENERAL NOTES: 1. SEE SHEET MP6 AND FOR PLANTING OETIJLS AND REOUIR[M[NTS. 2. LOOSEN ANY SOILS IN PLANTING Afl.EAS COMPACTED BY CONSTRUCTION ACTlVTTIES BY RIPPING OR TILLING THE AREA TO A DEPTH OF 24 • 3. PLANTING AREA LIM ITS AND INTERPLANTING LOCATIONS SHALL BE STAKED IN THE FIELD AND APPROVED BY PROJECI RlPRESENlATIVE PRIOR TO PLANTING . 4 ALL PLANTS TO BE SAVED AND PROTECTED WITHIN CLEARING AND GRUBBING Afl.EAS WILL BE fl.AGGED BY PROJEC T REPRESENTATIVE. NOTIFY ENGINEER 5 DAYS PRIOR TO STAA T Of CLEARING ACTMTY. USE ONLY HAND TOOLS AND METHODS WH EN WORKING INSIDE THE ORIPLJNE AAEA Of EXISTING TREES AND SHRUBS . 5 PLANT DEBRIS FROM REM OVAL OF INVASIVE PLIJNTS OR PRUN ING SKALL BE REMOVED FROM THE SITE AN O DISPOSED OF PROPERLY. LEGEND: --------URBAN CONSERVANCY BUFFER WETLAND 80\JNDAfl.Y ------OROI NAAY HIGH WATERLINE • ------· DESIRABLE VEGETATION EDGE EXISTING TREES ..-¥· "-7.. EXISTING TREES TO BE REMOVE D ~'?\, z'. \,. HABITAl LOG , SEE SHEET MP-6 * BRUSHPILE , SEE SHEET ~P-6 TILL Ml.EA TO 2•. DEPTH c ::::;::c;:::::;:1c::;::cJ STRAW WATTLE PLANTING QUANTITY TAB · THIS SHEET ONLY· QUANTITY BVC2 18 ,496 SF OUANTITY 11,~}\F 14 H 14 95% REVIEW SUB MITT AL NOT FOR CONSTRUCTION MITIGATION PLAN DRAWll'\C r,w 51 OF 59 MP4 . . ~ 2 .- 1 ~ " - -~-- --.----- I I \ -------- \ \ +\ '"" -----------~~-~------~----------------~--------' - /' , i l; ;! ~ ; ! ---\ ---~~----""-, ~ New Buffer Vegetation Conservation Planting Areas for ass in BVC1 and BVC2. '""-,, ' "" \ ~ a) ~ ft i ~ ! ·---...... ------. " ...... "'-~ ' "'-"" ' "' { ',..._~\~ . _ .. --C"""~ "" ----~ ------------~, 0 I ~ i ~ ~ I ~ I i ~ ~ ~ f % .. I ~ ::i " j! y OE:SIGNEO t 6 REVISIONS OA TE B J. SWENSON ORAW'-1 J . SWENSON ~ CHE CKEO ~ 0. KIKUTA ~ APPRO\'£D :'i <'. ' ' ONe INC H AT ~ULL SCA.Le:. IF N O T , SCALE ACCORDINOL Y '~ -- ~11!!"~- PLAN ® SCALE I N FEET N 0 20 40 • STATE OF W6~~~fl8N "iii:"" " + ' ~ -----... ENOINU:RIN G . P'I.ANN ING ENVIRONMENTAL SCIENCE$ PROXC1 NAM ( LAKE TO SOU ND TRAIL SEGMENT A GREEN RIVER TRAIL TO NACHES AVE SW CONSTRUCTION NOTES: r,\ MITIGATION CL£AR1NG AND GRUBBING. STAI<[ OR FlAG \_:J PROPOSED PLANTING AREA LIMITS FOR APPROVAL Of PROJECT REPRESENTATM PRIOR TO STARTING CLEARING WORK. CLEAR AND GRUB ROOTS AND REMOVE AND DISPOSE OF AU. UNWANTED VEGETATION IN THIS PLANTING AREi\. L£AVE SOIL IN PLACE. SEE SPECIFICATION FOR UST OF UNWANTf:D VEGETATION. (';\ COMPOST. PLACE J" LAYER COMPOST O'IER THE ENTIRE \:.) SURFACE OF THIS PLANTING AREA (';\ WOOD CHIP MULCH. PlACE 3• LAYER WOOD CH IP MULCH \.:::,) OVER THE ENTIRE SURFACE OF THIS PLANTING AREA. GENERAL NOTES : I . SEE SHEET MP6 AND FOR PLANTING DETAILS AND REOUlREMENTS. 2 . LOOSEN ANY SOILS IN PLANTING AREAS COMPACTED BY CONSTRU CTION ACTMTIES BY RIPPING OR TIWNG THE AREA TO A DEPTH or 24". 3. PLANTING AREA LIMITS AND INTERPLANTING LOCATIONS SHALL BE STAKED IN THE FIELD AND APPROVED BY PROJECT REPRESENTATIVE PRIOR TO Pl.ANTING. 4 . ALL PLANTS TO BE SAVED AND PROTECTED WITHIN CLEARING AND GRUBBING AREAS WILL BE FLAGGED BY PROJECT REPRESENTATIVE. NOTIFY ENGINEER 5 DAYS PRIOR TO START OF CLEARING ACTMTY. USE ONLY HAND TOOLS AND METH ODS WHEN WORKING INSIDE THE DRIPUNE AREA or EXISTING TREES AND SHRUBS. 5. PLANT DEBRIS FROM REMOVAL OF INVASM PLANTS OR PRUNING SHAU BE REMOVED FROM THE SITT: AND DISPOSED OF PROPERLY. LEGEND : "- ¥® * URBAN CONSERVANCY BUfHR WETLAND BOUNDARY ORDINARY HIGH WATERLINE DESIRABLE VEGETATION EDGE EXISTING TREES EXISTING TREES TO BE REMOVED HABITAT LOG. SU SHEET MP-6 8RUSHPIL£. SEE SHEET MP-6 TILL AREA TO 24. DEPTH ======· STRAW WATTlE PLANTING QUANTITY TAB • THIS SHEET ONLY • ---_QUANTITY Ml I M2 95% REVIEW SUBMITTAL NOT FOR CONSTRUCTION MITIGATION PLAN ORA.WING NO 50 OF 59 MP3 ~ :ii ;;; 6, ~ ~ .· t t Ji ,,, ~ 0 .i ~ ! ~ ~ § ~ / ~ . C, / g ~ ~ 0 I '.;'- ~ § 1l ~ ~ i : I :;: ;;; .i f ·! ~ f I I I ~~r~ ~ i::~ ?:: ::, u a:: --> UI---------------.. --. P/L ~' ' . . '-' ' "I " . I ~ ;,~£ . ,, --~~ 3~~ -----~ ( o..o __ \ ' . --------.:...,_i_.__ H I fif]\; ~~ ....... --------, I I 8£i4ck 9h--J .. .,.t:'Ji I ·-.. -. ·-··-.. _ .. -. / 'Vj !llJ ----/~ ~f:._4-;::_-::_--:,::; 11,719 square feet of the Buffer Vegetation Conservation Area ( BVC 1 ) proposed in the 60% design level was on railroad-owned property , and will instead be relocated to new areas along the river east of Monster Road . I I J ..... 0= i::~ u~ PLAN SCALE IN FEIT 0 20 f'/...___--\BLACK RIVER_ ------... ......._-------' ---- 1-·· --· \ V v, ~-/ ,-J ' / ~:..~"~ o, ( ----( !:: -----...... _ -- / ~,' \/~ < ' ' "\ :t ~_::.___ r--' % ________ .,_ __ t~ ~ . ' ~· -" /'~ -----------/ UI ---------' -~--~-in r -----,,_ ', -~ --~~--"'\---, ,,, , r--=---.. ~ -- > '--,.:~-' ----,=,-····· ,. ,-7'----_ ----c,,;cc,. · '-A 0' / / J'----.Le..---,-_7_7_-:_-=~--------'--.., -< ,.. , -----c' "'' /, /,..,.-; \ , -----<-----c, / '/ , ----C ''y.._C... /~ / --/ , / ' / ' / ' \ I PLAN ~ SCALE IN FEIT N 0 20 40 "\ ' 7§ ,; ' I l-----J )(~ --~~.... , __ 'y~ ---, +04-1 --:;:- _3S'~ ~ ~~ <"o,'.'Oo, 0-f() ~~ -----1:/1,_::__ ~~ ---~ ' -~ ' BLACK RIVER --/ _____ _ ~ ----------ii7ir LICENSED i!: LANDSC APE ARCHITECT PflOJE CT r-i.:.ME STRUCTION NOTES: 8 MITIGATION CLEARIN G AND GRUBBING. STAKE OR FLAG PROPOSED PLANTING AREA LIMITS FOR APPROVAL OF PROJECT REPRESENTATM: PRIOR TO STARTING CLEARING WORK. CLEAR AND GRUB ROOTS AND REl.4 0VE AND DISPOSE OF All UNWANTED VEGETATION IN THIS PLANTING AREA LEAVE SOIL IN PLACE. SEE SPECl flCATION FOR LIST OF UNWANTED VEGETATION. 0 COMPOST. PLACE 3-LAYER COMPOST OVER THE ENTIRE SURFACE Of THIS PLANTING AREA. I,\ WOOD CHIP I.IULCH. PLAC E 3• LAYER WOOD CHIP MULCH \:.) OVER THE ENTIRE SURFACE OF THIS PLANTIN G AR'fA. GENERAL NOTES : 1. SEE SHEET MP6 AND FOR PLANTING DETAILS AND REQUIREMENTS. 2. LOOSEN Al{'( SOILS IN PLANTING AREAS COf.lPAC TEO BY CONSTRUCTION ACTMTIES BY RIPPING OR TILLING THE AREA TO A DEPTH OF 2~" 3. PtANTING AREA LIMITS AND INTERPLANTING LOCATKlNS SHAll BE STAKED IN THE FIELD AN D APPROVED BY PROJECT REPRESENTATM: PRKlR TO PLANTING. 4. All PLANTS TO BE SAVED AND PROTECTED WITHIN CLEARING AND GRUBBING AREAS WILL BE FLAGGED BY PROJECT REPRESENTATM:. NOTlf'Y ENGINEER 5 DAYS PRIOR TO START OF CLEARING ACTMTY. USE ONLY HAND TOOLS AN O l.4ETHODS WHEN WORKING INSIDE THE DRIPUNE AREA OF EXISTING TREES AN D SHRUBS. 5. PtANT DEBRIS FROM REMOVAL OF INVASM: PLANTS OR PRUNING SHALL BE REt.10\/EO FROM THE SITE AND DISPOSED OF PROPERLY. LEGEND: --------URBAN CONSERVANCY BUFFER WETLAND BOUNDARY -------ORDINARY HIGH WATERLINE · ~-----• DESIRABLE VEGETATION EDGE X• I x·'· ~ ", '. , ~- ' ' \- * EXISTING TREES EXI STING TREES TO BE REf.lOVED HABITAT LOG, SEE SHEET MP-6 SRUSHPILE. SEE SHEET l.4P-6 TILL AREA TO 24. DEPTH c:=====· STRAW WATTLE PLANTING QUANTITY TAB -THIS SHEET ONLY - Q\/ANTITY SEE SHEET 1.4 PJ FOR MORE INFORMATION 95% REVIEW SUB MITT AL NOT FOR CONSTRUCTION • W~g~1~8bN t l::, R(VSIOSS DATE BY 0 "'}"'~WENSON LAKE TO SOUND TRAIL ~ DRA.7-" SWENSON AJ~·,: ... ,. ...... PLAN.iNO .EN~RONM<N"CSCIENCU SEGMENT A I MITIGATION PLAN I I 'i CHECKED " I M P2 '-0. KIKU TA GREEN R IVER TRAI L TO NACHES AVE SW I -~-----~ ORA Wl'IG NO 49 OF 59 ~ .. • 1 ~ j I ~ t / ~ . ~ ~ ~ ~ ' ~ J. ; ~ f ii j ! ; ' ii ~ ~ % ·! i :, ---~~------ ,,,,.,,--------------------0 * ,,,,,,,,i~*oO*~o o *o * o oo ~ * * o* GREEN RIVER GREEN RIVER TRAIL ~ I ·~ ** I~ ,m 111.1 1; ~x 6* I L . -=::::!---~ ~ ~. u -~~::--<§-®-~~~ ~~ I ~=--4 --=-4 --=-4--=-4 -=-4 -=--•-----•i I ----I -----------------------------------,,,,.---., ... ., ... I PLAN ® SCALE IN FE ET ~ FORT DENT PARK 40 ·-= TREE REPLACEMENT CALCULATION FOR SIGNIFICANT TREES DIAMETER• OF TREE I :~~rMrtT I NUMBER OF I N¥:E~~R TgF REMOVED (•MEASURED AT HEIGHT OF 4.5 FEET TREES REQU IRED TREES REMOVED REPLACE ONSITE FROM THE GROUNO ) 4 -6 INCHES (SINGLE TRUNK); 2 INCHES (ANY TRUNK OF A 3 1 3 MULTI-TRUNK TREE ) OVER 6 -8 INCHES 4 2 8 OVER 8-20 INCHES 6 5 30 OVER 20 INCHES 8 2 16 TOTAL 10 5 7 O 20 , / . ' ' . ' ' ~ffi '"-/ ...f/L------j ii ~-----, "-/ ---' -0 '---..___ IILACl{RIIIER / ----------------L----. * o ---..___________ /r -=-2!l!"--~-_,;:-o .,,...*,~~~c~~ * * "--"!4ot_-----,-~ ~ ---0'=--* o O ~ o ~ O:.~--,c--d-"''"'.,_.~<, · ------~-..:..~m -------------_PA -----_::-::----~· 0 ~ . ~ 0 •!>v ---.,.. ---------, · o * 4 o ~, -"-·--=-'-· ~:_~-::::--~"'---*-· -----------r------, ·! ~ ,----,' --* 0 " ,-,., ,, -/A,UE --ca· " V ~ -----c. ____ " ~-;o-!O ~? ----:;::::"'--1\ o·· ~"--.. '' ~ ,!; -' -___ ,_ ' ' ---~ -=.-.=•=-=..-.=:..F=:!.:: --... -6r-F-- __ ,. _____ ,_ X • _,.---=-=-~---. ,. , ·--' o:E J -" ' ~-;--* I I .......... .......... .......... .......... ----------i I --' ----' ----------. -----------~-----~--------------I PLAN----------------------------------------------i ---' FORT DENT PARK ----~~~-----~~-~iiiiiiSilCALE~~INiiiiiiFEiET~~. ®-_ ""' , ----- 0 20 CONSTRUCTION NOTES : 8 PLANTING AREA CLEARING AND GRUBBING. STAK E OR flAG PROPOSED PLANTING AREA LIMITS FOR APPROVAL o r PROJECT REPRESENTATM PRIOR TO STARTING CLEARING WORK. CLEAR AND GRUB ROOTS ANO REMOVE AND DISPOSE OF ALL UNWANTED VEGETATION IN THIS PLANTING AREA. LEAVE SOIL IN PLACE. SEE SPECIFlCATION FOR LIST Of UNWANTED VEGETATION. 0 0 COMPOST. PLACE 3-LAYER COMPOST OVER THE ENTIRE SURFACE OF THIS PLANTING AREA. WOOO CHIP MULCH . PLACE 3• LAYER WOOO CHIP MULC H. GENERAL NOTES : 1. SEE SHEET MP6 ANO roR PLANTING DETAILS AND REQUIREMENTS. 2. LOOSEN ANY SOILS IN PLANTING AREAS COMPACTED BY CONSTRUCTION ACTMTlES BY RIPPING OR TIWNG THE AREA TO A OEPTH OF 24 ". 3. PLANTING AREA LIMITS AND INTERPLANTING LOCATIONS SHALL BE STAKED IN ,HE FlElO AND APPROVED BY PROJECT REPR ESENTATM: PRIOR TO PLANTING. 4. ALL PtANTS TO BE SAVEO AND PROTECTED WITHIN CLEARING ANO GRUBBING AREAS WILL BE FLAGGED BY PROJECT REPRESENTATM:. NOTIFY ENGINEER 5 OAYS PRIOR TO START OF CLEARING ACTM1Y. USE ONLY HANO TOOLS AND METHODS WHEN WORKING INSIDE THE ORIPLINE AREA OF EXISTING TREES ANO SHRUBS . 5. PLANT OEBRIS FROM REMOVAL OF INVASIVE PLANTS OR PRUNING SHALL BE REMOVED FROM THE SITE AND OISPOSEO or PROPERLY. LEGEND : --------URBAN CONSERVANCY BUFFER WETLAND BOUNDARY -------OROIN.ARY HIGH WATERLINE • ------· OES1RA8LE VEGETATION EDGE EXISTING TREES ~~® EXISTING TREES TO BE REMOVED HABITAT LOG, SEE SHEET MP-6 BRUSHPILE. SEE SHEET MP-6 TILL AREA TO 24. OEPTH t * PLANTING QUANTITY TAB -THIS SHEET ONLY· QUANTITY o.c. 95% REVIEW SUBMITTAL NOT FOR CONSTRUCTION tiA.Tr lay I OES1CNE£.,NS0N ~l 6l·"''"M 1--1 m v,, ~ 2 1---4------------+---+----i DR AWN J. SWENSON CHECt<EO LICENSED IF NOT, SCALE ACCOROINGLY PROJECT NAME DRAWING NO 48 OF 59 40 • WASHI N80N ~~ === AACe"'cr LAKE~~o'.;'i.:',°,'RAIL MITIGATION PLAN 11 MP1 ONE INC H AT F ULL SCAL E . AP~ l:HGIH[ll!:JllNG .PlANNING .ll!:N Vll'\ONMl!NTALSCIENCE$ 11 " ""' 656 GREEN RIVER TRAIL TO NACHES AVE SW L _______________________ _ I I ~v '" 11 ···55·4 1521 084 {A/2C) 1 2:...!5.!""-· OV!:O l 0"1\oVEMBER 2016 l ~ 4 ~ AP PROvt( ~ ~ ~ ~ ~ .; i ~ ~ ~ < f ! t § 5 o:' / ~ . i -:, ? . 0 ~ ~ ;, ~ ,;1 i ~ :;j I i ; ~ :;; 'i % i 5 8 ~ \ \ \ \ \ \ \ \ ' I \ \ \ \ \ ) I I KC PARCO. NO. 3n9200117 CllY or ROITON PLAN SCALE IN FEET 1------~-~~---~-----------v ------------------------------------- 00 ~ ------ .c. -c..=-~ -----;uut:r _ .;:=::: r----r.-.4'·'''·=-~f. -----·--~ I I 7 I I I ,;;-;._Do· ev~ -:--- I I I I I I 1----------------------/ I --------' I I KC PARC(l NO. ll2.l049012 CllY or RENTON 0 PLAN SCALE IN r EET 40' -~ 80' ; I 6 I •<vs,oo~ ~-J~ __ _] D(S,f'?WENSON I r--;;;;;;;;;;;;;;---, ONE INCH AT FULL SCALE. IF N Oi, SCALE ACCORDINGLY WASHINGTON LICENSED LANDSCAPE AR CHITECT • STATE OF A,st I I I I I :::~~E;:~;AON 11 _ o.7~~mo•r~•V'L~v-~r l A!>?ROVCD -----.~ ---,o ,~ _=•-,ltl -::=. ::-_---=.J t/l ·----,-r-::.r:-~~ ~ v '~ I U --------- \ i WETLAN~ ,-\ 3 10 \ ~~: I / ·~ '= I I ,-, ,,-' ,," I I ,, ,," " ' I '----' I I ', ,,"" ', ,,"" ' ,," , __ .,,, KC PARCEL NO 1323049012 (lty or RENTON KC PARCEL HO. 1323049020 BNSF -------------- I I I I --....._ ' KC PARCEL NO. >77920011 7 (llY or RENTON --..... '>,,--. KC PARCU NO. 13230<9012 CllY or REIIION ------------------..... WETLAN01/2 COIFLEX /1\ --..... ......___ ......__ ENGINEEl'I.ING PU NNING l!NVl~MENTAL SClfN<::fS #4 ~ ----,·;:: ----~ --, P ROJ(CT NAM[ LAKE TO SOUND TRAIL SEGMENT A ......__ GREEN RIVER TRAIL TO NACHES AVE SW COi 0 0 0 0 JCTION NOTES: MITIGATION CLEARING ANO GRUBBIN G. STAKE OR FLAG PROPOSED PL.ANTING AREA LIMITS FOR APPROVAL OF PROJECf REPRESENTATrvE PRIOR TO STARTING CLEARING WORK. CLEAR AND GRUB ROOTS AN D REMOVE AND DISPOSE OF ALL UNWANTED VEGETATION IN THIS PLANTING AREA LEAVE SOIL IN PL.ACE. SE( SPECln CATION FOR LIST OF UNWANTED VEGETATION. COMPOST. PL.ACE 3" LAYER CO MPOST OVER THE ENTIRE SURFACE OF THIS PL.ANTNG AREA . WOOD CHIP MULCH. PL.ACE 3" LAYER WOOD CHIP MULCH OVER THE ENTIRE SURFACE OF THIS PLANTING AREA. SITE ACCESS. RESTORE AREA AITTR CONSTRUCTION PER THE REDUIREMENTS or NOTE #9 OF THE PLANTING NOTIES ON SHEET MP-6. GENERAL NOTES: 1. SEE SHEET MP6 AN D FOR PLANTING DETAILS ANO REQUIREMENTS. 2. LOOSEN ANY SOILS IN PL.ANTNG AREAS COMPACTED BY CONSTRUCTION ACTIVITIES BY RIPPING OR TILLING THE AREA TO A DEPTH or 2C 3. PLANTING AREA LIMITS AND INTERPLANTING LOCATIONS SHALL BE STAK ED IN THE nELD AN D APPROVED BY PROJECT REPRESENTATIVE PRIOR TO PLANTING. 4. ALL PL.ANTS TO BE SAVED AND PROTECTIED WITHIN CLEARING AN D GRUBBING AREAS WILL BE FLAGGED BY PROJECT REPRESENTATIVE. NOTIFY ENGINEER 5 DAYS PRIOR TO START or CLEARING ACTIV1TY. USE ONLY HANO TOOLS AN O l.lETHOOS WHEN WORKING INSIDE THE DRIPUNE AREA or EXISTING TREES AND SHRUBS 5. PL.ANT DEBRIS FROM REMOVAL OF INVASNE PLANTS OR PRU NING SHALL SE REMOVED FROM THE SITE ANO DISPOSED OF PROPERLY. LEGEND: J >!-~ ~ ·~- * URBAN CONSERVANCY BUFFER WETLAND BOUNDARY ORDINARY HIGH WATERLINE DESIRABLE VEGETATION EDGE EXISTING TREES EXISTING TREES TO BE REMOVED HABITAT LOG, SEE SHEET MP-6 BRUSHPILE. SE£ SHEET MP-6 PLANTING QUANTITY TAB -TH IS SHEET ONLY - I o.c I MYRTLE CURRANT SPS SP6 SP7 I SP8 4 2 6 2 2 15 15 10 ''! : o.c. I se;o I "" J~' 3 2 12 I 3 95% REVIEW SUB MITT AL NOT FOR CONSTRUC TI ON 0RAi'l1NG NO 53 O F 59 MITIGATION PLAN MPG KC PARCEL NO. 3779200119 cm or RENTON SP1 c5 " I ,, I ' , .~ ',, / ', ' I , ' I 0 0 0 I "'-', ', ' I "', __ ,, :! ~ e i >. i t ; _._ _._ .•. _._ ..,.._ ..LIJ.. ..LIJ.. ..,,. ..,,. ..LU.. -..WU.. = = -... .... ..LU.. ....... --_._ I .ll<. ' ...iii. ' ~ I I I I -*-_._ ..... _._ ..... .... ... ... ./ ... .._ ...W.. ..1.lL ~ ..1IL ...ilJ... ..1IL ..LlL. ..LIL ~ ..W.. I ..uw.. ..WU.. -...iu... ---~ --_._ _._ _._ _._ _._ _._ _._ L ... ... 'V.,_·..,,. ..... ..,,.-"'-..,,. _..,._..,,. ..,,.,,..,.._-"'-....._ "-~ JI.. -------~ ~ -"<'.-4.. ... ·*-... _._ _._ -*--*-_._/, _._ BR .•. "' ~ ..11.L.. ~ ..w.. ..w.. ..w.. ..w.. ..LLf.. ..w.. ~ ..w.. ..w.. ' JI.. --..WU.. ----tt:----- -,.~.. ..,,. _._ ..,.._ .... ..LIJ.. ... ..LIJ.. .... ..LIJ.. ... ..LIJ.. ... / ---...... _._ ..LIJ.. _._ """-------.,ti..-- ' I ... ,.._ ... ... ... & & & _._ .•. ....._ ..,,. --.... ·*-..,,. = .ll<. ..,,. .•. -... = ..uw.. ..,,. .., < 0 ....._-,....._ ..LIJ.. ..,,. ..LIJ.. =; ..... ...,_ ~ -~,---~· ------.... .... _......... ..... -*-... ; .... ... ... ·*-.. _ JI. i f ! /;, ..U. ..U. -'"-"( ..1.lL.. ..LlL.. ,' ...J.IL.. ..a.IL ..a.t&.. ..W.. ..W.. ..W.. ~ ~ ----1---.............. _._ ,._._ _._ ... ..W.. ..llL. ..11.t.... ' ..LIL i -11L. ..1.1.L. ..LIL ----.... .... .._ .... ..... ..... ....._ ....._ ~ ~ f i .,. ~ < i i I '.'] 'I,,,. --------' ' .... ...... .... v ..._ _ ...... llJ.. ..w.. .JJ.&.. ... ..w.. .J.IL. ..u&... ..1.lL --:.., ----~-*-..w..~,.41.L....._ ..w.. ..... ..u&... ~ ~ -' " ' '"-, ' '\ ' \ -... ..,,. ...iii. .•. = - ' ' \ -.•. ....._ -... ..,,. -·-....._ .... ~ ' ~ l ~<.. \-o i 0,t-l _____ _ELL __________________ ~~~ iii I --~ ' j f ' --. .. . .. ....._ --·-..,,. --*· .•. ' ,0 ~' ... -... CONSTRUCTION NOTES: -, 0 ~:~~~ ~~g :~ G~~~~1%t::J:AL n: ~ PROJECT REPR ESENTATM: PRIOR TO STARTI NG CLEARING ( l,_ WORK . CLEAR ANO GRUB ROOTS ANO REMOVE ANO '· ) I DISPOSE OF ALL UNWANTED VEGETATION IN THIS PLANTING • ·. AREA. LEAVE SOI L IN PLACE . SEE SPECIFICATION FOR .... -"'- \~ STREAM auJa ENHANCfi.ENT ~~SITE113 / I I I _._ --_._ ..,,_ -"'- ... ...... ...... ...... , \ \ I I I I I I I ' I~ I " ',,,, I I ', I ' I ', l ' ' ' ~ ' , ~ KC PARCiL NO. )779200118 CITY or RENTON ', ~ ~ ' ~) ,,_ ', I 'w ' , /w ..,,. ... .llJ.. ---... ... ... ..LIJ.. ....._ ....._ ---... ... ..,,. ..,,. ....._ -... .•. ..,,. ' ' l: ' I "' \ ' \ ' ,w I / ,w I ,' u, ,f ff 1., -I , I I l: //' ,~ ,' / 1: ,/ I , I ,/ I I '} UST OF UNWNITED VEGETATION. 0 0 8 COMPOST. PLACE 3" LAYER COMPOST OVER THE ENTIRE SURFACE OF THIS PLANTING AREA. WOOD CHIP MULCH. PLACE 3" LAYER WOOD CHIP MULCH OVER THE ENTIRE SURFACE OF THIS PLANTING AREA . SITE ACCESS. RESTORE AREA AFTER CONSTRUCTION PER THE REQUIREMENTS OF NOTE #9 OF THE PLANTING NOTES ON SHEET MP-6. GENERAL NOTES : 1. SEE SHEET MP 6 ANO FOR PLANTING DETAI LS ANO REQ UIREMENTS 2. LOOSEN ANY SOILS IN PLANTING ARf.J,S COMPACTED BY CONSTRUCTION ACTMTIES BY RIPPING OR TILLING THE AREA TO A DEPTH OF 24". 3. PLANTING AR EA LIMITS AND INTERPLANTING LOCATIONS SHAU. BE STAKED IN THE FIELD AND APPROVED BY PROJECT REPRESENTATM: PRIOR TO PLANTING. 4. ALL PLANTS TO BE SAVED AN D PROTECTED WITHIN CLEARING AND GRUBBING ARW WILL BE FLAGGED BY PROJECT REPRESENTATIV£. NOTIFY ENGIN EER 5 DAYS PRIOR TO START OF CLEARING ACTMTY. USE ONLY HANO TOOLS AND METHODS WHEN WORKING INSIDE THE DRIPLINE AREA OF El11STING TREES ANO SHRUBS . 5. PLANT DEBRIS FROM REMOVAL OF INVASM: PLANTS OR PRU NING SHALL BE REMOVED FROM THE SITE AN D DISPOSED OF PROPERLY . LEGEND : .:JI "' *,,J ~~ / { V t * URBAN CONSERVAN CY BUFFER WETl.AND BOUNDARY ORDINARY HIGH WATERLINE DESIRABLE VEGETATION EDGE EXISTING TREES EXISTING TR EES TO BE REMOVED HABITAT LOG. SEE SHEET MP-6 8RUSHPILE. SEE SHEET MP -6 I I (' I I ' I -I KC P/ORCO. _/ 1 'l. V , / CITY orNO 3779200111 / -,. " ' I """ L_ ,--~-,~, =~ I I I --~' , I J ' I I -,..I _ P /, DESIRABLE \ / / ·-4 ,r ' I ] PLANTING QUANTITY TAB • THIS SHEET ONLY • I •• -GETATION EDGE ' ,' I I -\ ' 1' r---' I~ ---\ / / I -~, I I """"' OUITTR • -•. '..._ ~ / ,' : ( \-----,' / / ,, I , ----L ,' : I ' I I I ' ·I I ' ,,1 --P /t• , I ' • .._,_ ' ' ,, ,, --_j ' ---~ --- ,,~STREAM BUFFER ' - - P/L ---------- O.C" o.c.: :ia.c!M sr JQ fil 15 °46 76 ~ I r 6 ,7 ~; ~ : SP3 2 2 20 20 20 Iii Iii \i i -----' VY "' ' 7 ""' 'Y ~ ~ ', ( i ,__,.. ~ i 'O 4 0' • so·· STATE OF ' ---------~--~---' 95% REVIEW SUB MITT AL NOT F OR CONSTRUCTION ,,. @ WASHINGTON :, LICENSED <= ~--~ LANDSCAPE ARCHITECT < OAT[ BY O(SICNED ~ Q. 6 RE\ 1 Sl0NS J. SWENSON ONE INC H AT FULL S CALE. OR.:.WN IF N OT, SCALE ACCORDINGLY FRO..CCT NAME DR.6.~NG NO 52 OF 59 ~ J . SWEN SON ll <a'~~~2 1084PAT01200C-MP 656 "''"""'""-""' "-"'""" MPS a. CHEOC(D N BEu..E\\lE. WASr ,-.;:,ra,,. 1J1600,1 : 0 .KIKUTA ~55°4-1 521-084 /A /2C) AF~ I:.:.;;:.~.:..,"'""''" I II GREENR IVERTRAILTONACHESAVESW II II I LAKE TO SOUND TRAIL SEGMENT A MITIGATION PLAN E NGINEEltlNG . PUNNING . ENVIRONMENTAL SCIENCES ~ APPR Ov!:D OAT~OVE MBER 2016 :. £ ~ ~ " 1 • , le ~ t f r a, § 0 It r 9 ~ ? 0 ~ ~ )', ~ ~ § ~ I i;i 1 ~ i ! ~ 1 % ~ ~ Sl ~ ~, 6 1 MITIGATION GOALS, OBJECTIVES, AND PERFORMANCE STANDARDS THE OVERAll GOAL OF THE MITIGATION IS TO REPLACE TH[ HABITATS AN O FUNCTIONS LOST AS A RESULT OF TH[ PROJECT. TH[ PROPOSED MITIGATION WOULO ACCOMPLISH THI S BY ENHANCING 0.4 9 ACRE OF WETLAND BUFf[R ANO 0.60 ACRE or STREAM BUFFER ANO 0.60 ACRE STREAM BUFFER AT MITIGATION SITES I ANO 2. SPEClnc GOALS AN D OBJECTIVES FORMULATED TO ACHl(VE THIS RESULT AR[ PRESENTED BELOW. MITIGATION GOAL GOAL· ENHANCE 0.49 ACRE OF WETLAND BUffER AN D 0.60 ACRE OF STREAM BUFFER TO NATrvE FORESTED UPLAND. ACHIMMENT OF THIS GOAL IS EXPECTED TO INCREASE THE PRODUCTION OF ORGANIC MATTER BY PLANTI NG TREES AND SHRUBS IN THE ENHANCED BUFFER; INCREASE WILOLIFE HABITAT: AND IM PROVE BIOLOGICAL DIVERSITY BY PLANTING WITH A VARIETY OF NATIVE RIPARIAN PLANT SPECIES. MITIGATION OBJECTIVES AND PERFORMANCE STANDARDS OBJ[CTrvE 1: ESTABLISH A MIN IMUM OF O 49 ACRE OF FORESTED WETLAND BUff[R ANO 0.60 ACRE OF FORESTED STREAM BUFFER BY PLANTING NATrvE TREES ANO SHRUBS. PERFORMANCE STANDARD: YEAR 1 SURVIVAL OF PLANTED WOODY SPECIES IN ENHANCED WETLAND BUFFER ANO STREAM BUFFER AREAS \\1LL BE AT LEAST 80 PERCENT. YEAR 3 NATIVE WOODY SPECIES WILL ACH IM A MINIMUM OF 35 PERCENT AREAL COVER IN THE ENHANCED WETLAND BUFFER ANO STREAM BUFFER AREAS. YEAR 5 NATIVE WOODY SPECIES \\1LL ACH IM A MINIMUM OF 60 PERCENT AREAL COVER IN THE ENHANCED WETLAND BUFFER AND STREAM BUFFER AREAS. OBJECTM: 2: LIMIT INVASM: NON-NATM: SPECIES THROUGHOUT TH[ MITIGATION SITE PLANTING AREAS . PERFORMANCE STANDARD: YEARS 1-5 HIMALAYAN BLACKBERRY, CUTLEAF BLACKBERRY (RUBUS LACINVITUS), SCOTCH BROOM (CYTISUS SCOPARIUS), BUTTERFLY BUSH (BUODL[JA SP.), POISON HEMLOCK (CONIU M MACULATUM). CANV\DA THISTLE (CIRSIUM ARVENSE), BULL THISTLE (CIRSIUM VULGAR£), ANO REED CANV\RYGRASS Will NOT EXCEED 20 PERCENT AREAL COVER IN AU PLANTING AREAS . OBJECTM: 3 . PROVIDE UPLAND WILOUFE HABITAT. PERFORMANCE STANDARD: INCREASE IN AREAL COVER or NATIVE WOODY SPECIES IN TH [ PLANTED BUFFER. AS MEASURED IN OBJECTrvE 1 TO BE USED AS A SURROGATE TO INDICATE INCREASING flABITAT FUNCTIONS OBJ[CTM: 4: PROTECT THE MITIGATION SITE FROM ANTHROPOGENIC DISTURBANCE. PERFORMANCE STANDARD, YEARS 1-5 CONDUCT YEARLY OUALITATM: MONITORING TO ASSESS TH[ STATUS OF TH[ SITES DURING TH 5-YEAR MONITORING PERIOD FOR HUMAN DISTURBANCE. INCLUDING BUT NOT LIM ITED TO FI LLI NG, TRASH, AN O VANDALISM. 2 MONITORING AND MAINTENANCE 2.1 MONITORING THE MITIGATION AREAS WOULD BE MONITORED DURING ANO AFTER CONSTRUCTION. DURING CONSTRUCTION, MONITORING WOULD ENSURE THAT TH[ BIJPS ARE OBSERVED TO MINIMIZE IMPACTS. ANO THE ON-SIT[ CONSTRUCTION WORK (INCLUDING EARTHWORK AND PLANTING) WOU LD BE COORDINATED TO ENSURE THAT TH[ SITE IS CONSTRUCTED AS DESIGNED. AFTER CONSTRUCTION IS COMPLETED. AN "AS-BUILT' MITIGATION REPORT WOULD BE SUBMITIED TO TH[ CITIES OF RENITON ANO TUKWILA WITHIN 1 MONTH OF MITIGATION INSTALLATION. POST-CONSTRUCTI ON MONITORING OF TH[ MITIGATION AREAS WOULD BE PERFORMED OVER A 5-YEAR PERIOD BY QUALIFIED BIOLOGISTS. THE CITY Of RENTON SHALL HAVE TH[ AUTHORITY TO EXTEND TH[ MONITORING PERIOD TO 10-YEA,qS AS CONDITIONED BY THE HEX DECISION . MONJTORING WOULO B[ PERFORMED OUART[RLY THE FIRST YEAR AN D ANN UALLY FOR SUBSEQUENT YEARS TO ENSURE THAT TH[ GOALS ANO OBJECTM:S OF THE MITIGATION AR[ BEING MET. A COMBINATION OF QUALITATIVE AND OUANTITATM: MONITORING ACTIVITIES WOULO BE USED TO ASSESS THE MANAGEMENT OBJECTIVES ANO ASSOCVITED PERFORMANCE STANDARDS OCSCRIBED IN THIS MITIGATION PROPOSAL. ACTMTIES WOU LD INCLUDE CONDUCTING SITE VISITS TO MONITOR UNNATURAL SITE DISTURBANCE, TAKING PHOTOGRAPHS TO DOCUMENT SITE D(V[LOPMENT, AN O COLLECTING DATA FOR TH[ QUANTITATIVE (VAL UATION OF PERFORMANCE STANDARDS. TH RESULTS or THE MONITORING \\1 ll BE SUBMITTED TO THE CITIES OF RENTON ANO TUKWILA FOLLOWING EACH MONITORING MNT. APPROPRIATE CONTINGENCY MEASURES Will 6[ DEVELOPED, AS NEEDED, BY A QUALIFIED PROFESSIONAL TO ENSURE THAT TH[ SITES OCV[LOP HEALTHY VEGETATIO N THAT MEETS THE OBLIGATIONS OCSCRIB[D IN THIS MITIGATION PLAN AND TH[ ASSOC IATE D PERMITS. DESIGNEO J. $111:N SON R[VISIONS OAT( av ~ 1--1 I I I ::;r.E~l\£NS0N I I cc oamo•~~•v•<vv~-M, 0. KIK UTA "" ••- ONE INC H A T F ULL SCALE. IF NOT, S CALE ACCORDINGLY APPROVED 2.1 .1 QUANTITATIVE MONITORING THE f0LLOl\1NG BULLETED IT[MS DESCRIBE TH[ METHODS TO 3[ USED FOR TH[ QUANTITATIVE MONITORING, MONITORING SCHEDULE, ANO R[PCRT OEADUN[S. • THE MITIGATION SIT[$ WILL BE ASSESSED BY AN APPROPRLI.TE QUANTITATIVE VEGETATM: COVER Fl[LO ASSESS MENT METHODOLOGY. TH[ LINE INTERCEPT METHOD Will BE USED FOR DITTRMINING PERCENT AREAL COVER FOR WOODY AN D INVASrvE SPECIES. • QUANTITATIVE VEGETATION ASSESS MENITS Will FOLLOW TH [ SAME METHOD IN EACH CONSECUTrvE MONJTORING YEAR. • QUANTITATIVE VEGETATION ASSESSMENTS Will BE P[RFORMW BETWEEN JUN[ 15 AND SEPTEMBER 15 OF EACH MONITOR ING YEAR . • MONITORING RE PORTS WILL BE S[NIT TO AGENCIES REQUIRING MONITORING REPORTS 8Y FEBRUARY 15 OF TH[ FOLLOWING YEAR. • QUANTITATIVE MONITORING Will INCLUDE PHOTOGRAPHIC DCC UMENTATION OF THE SITES FROM PERMANENT PHOTOGRAPH STATIONS. 2.1.2 QUANTITATIVE MONITORING OUAUITATM: ASSESSMENT Will BE PERFORMED YEARLY TO VISUALLY ASSESS THE HEALTH or PLANTS ANO IDENTIFY AREAS THAT MAY NEED CONTROL OF NON-NATM: INVASM: SPECIES OR OTHE R MAJ NTENANC[ ACTMTl[S ADDITIONALLY. DURING YEARS 1, 2, AND 3 THE SCR[[NING PLANTINGS (SP-I) Will ALSO BE OUAUITATM:LY MONITORED TO VISUALLY ASSESS THE HEAL TH OF TH[ PLANTS ANO IDENTIFY AREAS THAT MAY NEED CONTROL OF NON -NATIVE INVASIVE SPECIES OR OTHER MAJNTENANC[ ACTM11ES. 2.2 MAINTENANCE TH[ PROPOSED MITIGATION IS INTENDED TO ACH l(V[ THE PERFORMANCE STANDARDS WITH MINIMAL ONGOING MAJNTENANCE. PLANTED VEGETATION SPECIES SHOULD BE ADAPTED TO VARYING Sil[ CONDITIONS IN TH[ PUGET SOUND LOWLAND; HOWEVER, SUPPLEMENTAL IRRIGATION MIGHT 8[ NEEDED DURING THE FIRST TWO GROWING SEASONS AFT ER INSTALLATION TO ENSURE TH[ LONG-TERM SURVIVAL OF THE PLANTS. THE NEED FOR IRRIGATION WOULD BE (VALUATED BASED ON TH E CONDITIONS OBSERVED DURING TH[ [STABUSHM[NIT PERIOD. TO ENSURE RAPID ESTABLISH MENT OF THE PLANT COMMUNITY. TREES AND SHRUBS WOULD BE PLANTED CLOSER TOGETHER THAN WOULD GENERAllY OCCUR IN NATURAL MATURE STANDS. SOM[ NATURAL MORTALITY IS EXPECTED TO OCCUR DURING TH E MONITORING PERIOD. All DEAD AN D DOWN ED WOODY MATERV\L WOULO BE LEFT IN PLACE TO PROVIDE MI CROHABITATS FOR WILDLIFE PLANTS WOUUD BE REPLACED AS NEEDED TO MEET PERFORMANCE STANDARDS MAINTENANCE TO CONTROL NUISANCE SPECIES IN TH[ MITIGATION AREAS MAY B[ NECESSARY. DURING THE MONITORING PERIOD. If IT BECOMES E'.1DENT THAT INVASM: SPECIES AR[ IM PEDING ESTABUSHMENT OF DESIRABLE NATI\/[ PLANTS, MEASURES WOULO BE IMPLEMENTED TO CONTROL NU ISANCE SP ECI ES. A PROGR[SSM:LY AGGRESSIVE APPROACH WOULD BE USED TO CONTROL NUISANCE SPECIES. CONTROL MEA,~URES WOULD FIRST INCLUDE HAND CUTTING AN D/OR GRUBBING AND REMOVAL: IF THIS FAJLS, AN ENVIRONMENTALLY SENSITIVE HERBICIDE (RODEO' OR EQUIVALENT) MAY BE APPLIED. 2.3 CONTINGENCY MEASURES IF MONITORING IN~CAT[S THAT THE SITES AR[ NOT MEETING ViRFOR MANCE STANDARDS, CONTINGENCY MEASURES WOULD BE IMPLEMENTED (TABLE 2-1 ). SITE CONDITIONS WOULO BE (VALUATED TO DETERMINE TH[ CAUSE OF TH[ PROBLEM AN D THE MOST APPROPRLI.T[ COUNTER MEASURES. IN FOR MATION FROM TH[ ANN UAL MONITORING PROGRAM WILL BE USED TO IDENTIFY ANY MAJNT[NANC[ AND/OR CORRECTM: ACT IONS. IF PROBLEMS ARE IDENTI FIED IN MONITORING. KI NG COUNTY BIOLOGISTS \\1ll DETERMINE TH[ CAUSE OF THE PROBLEM AND IMPLEMENT PROPER MAINTEHANC[ OR CORR[CTM: ACTIVITIES. THESE ACTIVITI ES Will BE DISCUSSED IN THE ANNUAL MONITORING REPORT. TABLE 2-1. CONTINGENCY MEASURE S FOR THE MITIGATION SITES PROBLEM cONTINGENCY MEASURE LESS THAN 80!>: OF PLANTED WOODY I KING COUNTY BIO_OGISTS (OR OTHER OUALIFIED BIOLOGIST) SPECIES SURVIVE IN YEAR I WOULO ASSESS THE SITE TO DETERMINE v.iHAT CONDITIONS AR E PR[V[NTING THE PLANTS FROM THRMNG . APPROP RIATE MEASURES WOULD BE TAKEN TO CORRECT ANY CONDITIONS THAT AR E LI MITING GROWTH. LOST PLANTS WOULD BE REPLACED WITH A>'PROPRVIT[ NATrvE SPEC IES UNLESS APPROPRV\T[ NATIVE WOODY SPECIES AR[ VOLUNTEERING AT A RATE SUFFICIENT TO REPLACE THEM. ADDn lONAL MEASURES (SUCH AS PROVIDING ADDITIONAL PROTECTION) WOULO BE CONSIOERED IF NECESSARY. ADDITIONAL PROTECTION COUUD INCLUOC TH[ USE OF AN HERBIVORE REPELLENT (PLAN;SKYDO OR EQUIVALENT) PERCENT COVER FOR WOODY SPECIES NOT I KING COUNTY BIOLOGISTS (OR OTHER QUALIFIED BIOLOGIST) MET IN YEAR 3 OR 5 WOULD ASSESS TH[ SITES TO DITTRMIN[ WHAT CONDITIONS AR [ PRCV[NTING TH[ PLANTS FROM THRMNG. APPROPRLI.TE MEASURES WOULD 8[ TAKEN TO CORRECT ANY CONDITIONS THAT AR[ LIMITING GROWTH. INVASIVE SP[Cl[S EXCEED PERC[NIT COVER THRESHOLD PERFORMANCE STANDARDS NOT MET AT YEAR 5 WA SHINGTON LICENSED IMPLEMENT/RCVISE INVASM: SPECIES CONTROL PLAN. CONTINUE TH[ MONITORING REGIME FOR I ADDITIONAL YEAR. TH[ SITES WOULD CONTINUE TO BE (VALUATED (V[RY YEAR UNTIL THEY IIEET THE STATED PERFORMANCE STANDARDS ASSOCIATED 111TH Mv\NAG[M[NT OBJECTM:S. OTHER CONTINGENCY MEASURES MAY BE IMPLEMENTED DURING TH IS PERIOD. • STATE OF J =:=_::'"" ENG4NEERIHG . Pl.ANNING . li:NVlROH""-EHlAL $CIENCU PfWJfCT "!AME LAKE TO SOUND TRAIL SEGMENT A GREEN R IVER TRAI L TO NACHES AVE SW ·- I 95% REVIEW SU BM ITT AL NOT FOR CONSTRUC TION I 0 C1AW,NC NO 55 OF 59 MITIGATION NOTES MP8 ' ~ ~ ~ N ~ <> ~ ~ .. ~ ~ i ; ~ i ~ ,;. a, ~ ~ / ~ . ~ ~ ~ s ~ ~ ~ ! l:l ~ ~ ' ~ '.'), i lf :.':: ~ i ~ i $ Sl ~ :, 1 a. 6 PLACE J" DEPTH WOOD CH IP t.lULCH OVER ENTIRE PLANTED AREA. KEEP MULCH Off OF STEMS BACKflU WITH NATI\/£ SOILS. WATER THOROUGHLY TO REMOVE AJR POCKETS I PLANTING HOLE TO BE I 2 X DIA. OF ROOTBALL SHRUB AND SMALL TREE PLANTING DETAIL ffi NO SCALE 6 , cf TR EE 12 00 · flNISHED GRAOE COMPOST \------EXISTING SOIL lOI~ .llifil; PLANT SHRUBS IN SINGLE SPECIES GROUPS or 7 TO 12 PLANTS EACH PLANT TREES IN SINGLE SPECIES GROUPS OF I TO 5 PLANTS EACH. 4 ' ~06 ~"'"'"= RE Vl~ON S TYPICAL TREE AND SHRUB SPACING DETAIL ffi NO SC ALE DAT[ BY EDGE OF PLANTI NG AJREA OESICNED J. SWEN SON TREE STAKING "ARBOR TIE" ·eve· HEMLOCK/nR STAKE, 2" DIA (1 PER TREE) DRMN MO UNDISTURBED SUBSOIL MIN 2 4" DEPTH flNISHED GRADE BACKFILL WrTH NATI\/£ SOILS. WATER THOROUGHLY TO REMOVE AJ R POCKETS PLANTI NG HOLE TO BE 2 X DIA. OF ROOTBALL NOTE: STAKE All TREES 3' AND TALLER. PLANT so THAT TOP or ROOT BALL IS [V[N WITH THE flNISHED GRADE PLACE 3" DEPTH WOOD CHIP MULCH OVER ENTIRt: PLANTED AREA OR IN 5' DIA. t.l ULCH RINGS WHERE TREES ARE INflLL PLANTED. KEEP MULCH OFF OF STEMS COMPOST ~I ~ ~,~ ~9 'i: a) ;:R 2 :i "' I :... z :i '«:> PLANTING HOLE TO BE 2 X DIA. OF ROOTBALL NOTE: STAKE ALL TRt:ES 1 • CALIPER ANO GREATER. TREE STAK ING "ARBOR TIE" HARDWOOD STAKES PLANT so THAT TOP or ROOT BALL IS [V[N WITH THE flNISHED GRAOE PLACE 3· DEPTH WOOD CHIP MULCH OVER ENTIRE PLANTED AREA OR IN 5' OIA. MULCH RINGS WH ERE TREES ARE INFlLL PLANTED. KEEP t.l ULCH Off or STEMS flNISHED GRAOE COt.l POST BACKflLL WITH NATN[ SOILS . WATER THOROUGHLY TO RE MOVE AIR POCKETS EX ISTING SUBGRAOE PLANTING NOTES: 1. CONTRACTOR SHAU ARRANGE TO MEET ON SITE WITH PROJECT REPR ESENTATIVE TO DISCUSS LIMITS or WORK ANO METHODS. CONSTRUCTION ACTIVITIES SHALL NOT COMMENCE UNTIL ACCESS. LIMITS or WORK. AND METHODS ARE APPROVED. 2. MITIGATION PLANTING PlANS Rt:PRESENT A CONCEPTUAL PLANT LAYOUT. flNAL PLANT LOCATIONS SHALL BE AJPPROVEO BY PROJECT REPRESENTATM PRIOR TO PLANTING. 3. USE ONLY HANO TOOLS TO CLEAR ANO CULTNATE SOIL UNDER TH E CANOPY (WITHIN ANO 5' OUTSIDE THE DRIPUNE) OF EXISTING TREES. 4. ALL PLANTS SHALL BE NURSERY GROWN A MINIMUt.l or ONE YEAR. PLANT t.lATERW. IS TO BE SUPPLIED BY COM MERCIAL NURSERIES THAT SPECIALIZE IN PLANTS NATI\/£ TO TH E PAClnc NORTHWEST. PLANT SUBSTlTUTlONS ARE SUBJECT TO AJPPROVAL BY PROJECT REPRESENTATM. PLANTS SHAU MEET THE REQUIREMENTS OF THE LATEST ADDITION OF TH[ At.lERICAN STANDARD FOR NURSERY STOCK. 5. MITIGATION PLANTING SHALL TAKE PLACE DURING THE OORt.lANT SEASON (OCTOBER 1ST TO MARCH 1ST). PLANTING t.lAY BE ALLOWED AT OTHER TIMES AFTER REVIEW AND WRITTEN APPROVAL BY PROJECT REPRESENTATIVE. 6. THE CONTRACTOR SHALL BE RESPONSIBLE FOR DISPOSING or ALL DEBRIS ANO EXCESS SOIL OCCASIONED BY THIS PROJECT. 7. CONTRACTOR SHAU VERIFY THE LOCATION Of All UTILITIES PRIOR TO EX CAVATION. 8. ALL DIMENSIONS FOR LISTED HEIGHT, LENGTH ANO CONTAJNER SIZE ARE MINIMUt.l REQUIREM ENTS. 9. EXISTI NG AREAS DISTURBED BY CONSTRUCTION ACTMTIES ANO NOT SHOWN TO BE RE-VEGETATED ON THESE PLANS SHAU BE RESTORED AND SEEDED. THE CONTRACTOR SHALL REPLANT ANY NATM WOODY VEGETATKlN DISTURBED DURING CONSTRUCTION WITH SPECIES PROVIDED IN THE PLANT t.lATERW.S UST AT 1:1. CONIFEROUS TREE PLANTING DETAIL ffi DECIDUOUS TREE PLANTING DETAIL DETAIL ffi I 0. DISCREPANCIES BETWEEN THE PLANS AN D SITE CONDITIONS SHAU BE BROUGHT TO TH E AfilNTION OF TH E PROJECT REPRESENTAT II/£ PRIOR TO PROCE[DING WITH AF FECTED WORK. 11 . CONTRACTOR SHALL BE Rt:SPONSIBLE FOR WATERING PLANTS FOR THE FIRST YEAR AFTER ACC EPTAN CE OF COMPLETION or PLANTING FOR THE PROJECT. COUNTY WIU t.lAKE PROVISIONS FOR WATERING AS NEEDED FOR TH E REMANOER or THE ESTABLISHMENT PERIOD AFTER THE nRST YEAR. AMENDED NATIVE SO ILffi._/\ SEE DETAIL ~ NO SCALE .... ...... .... ;:. LIVE STAKE INSTALLATION DETAIL ffi NO SCALE I FINISH GRADE NO SC ALE SEE SPECIAL PROVISIONS FOR MATERIAL REOUIREMENTS ;,, g ;,., ' 0~--,-"/i~~-·1 8 ' , 8' I i~ BRUSH PILE DETAIL ffi NO SCALE 12" TO 18" DIA. LOGS. STAK E LOCATION OF LOG PLACEMENT WHERE INDICATED IN PLAJNS. ENGINEER SHALL APPROVE LOC ATIONS BEFORE LOG PLACEMENT EXISTING GRADE L-15' TO 25' .tiQlE.;. LOGS SHALL BE SALVAGED FROM TREES FLAGGED BY ENGIN EER FROM ONSITE WITHIN PROJECT CLEARING LIMITS. LICENSED LANDSCAPE AJRCHIT ECT HABITAT LOG DETAIL NO SCALE ffi PROJEC T NAME PLANT MATERIAL LIST BOTANICAL NAME Elli 59 ACER CIRCINATUM ' 9 4 ACER MACROPHYLLUM • 16 BETULA PAYRIF[RA • 9 FRAXINUS LATIFOLIA • 69 PICEA SITCHENSIS ' 4 6 POPULUS BALSAMIFERA • 178 PSEUOOTSUGA MENZIESII • 52 SALIX LUCIOA • 56 SALIX SITCH ENSIS ' 136 THUJA PLICATA ' ~ 266 CORNUS SERICEA 220 CORYLUS CORNUITA 247 CRATAEGUS OOUGLASII 357 HOLOOISCUS DISCOLOR 481 OEMLERL's CERAS1f0RMIS 469 MYRICA CALIFORNICA 270 RISES SANGUINEM 805 ROSA Nl/Tl<ANA 252 RUBUS PARVIFlORUS 831 SYMPHORICARPOS ALBUS ..tlQIE; 12 . PLANT TREES NO CLOSER THAN I 0-FEET ANO SHRUBS NO CLOSER THAN 8 -FEET FROM EDGE or ROADS. TRAJL WALLS OR SIGNS. CO MMON NAME MIN SIZE / CONDITION NOTES/ SPACING VINE t.lAP LE 1 • CAL. / CONT. OR 8&8 BIGLEAF t.lAPLE 1 • CAL. / CONT. OR 8&8 PAJPER BIRCH 1 • CAL. / CONT. OR 8&8 STAKE PROPOSED TREE LOCATKlNS IN OPEN OREGON ASH 3· HT. / CONT. OR B&B INnLL AREAS WITHIN SITKA SPRUCE 3' HT. / CONT. OR B&B PLANTING AREAS. PLACE WILLOWS CLOSER TO TH[ BLACK COTIONWOOO 1 • CAL. / CONT. OR B&B RMR EDGE. DOUGLAS FIR J' HT. / CONT. OR 8&8 PACIFIC WILLOW 1 • X 3· LIi/£ STAKE CUTIING SITKA WILLOW 1 • X 3' LIVE STAKE CUTTING WESTERN RED CEDAR 3' HT. / CONT. OR B&B RED -TWIG DOGWOOD 1 GAL CONT. BEAK ED HA2ELNUIT 1 GAL CONT. STAKE PROPOSED BLACK HAWT HORN 1 GAL CONT. SHRUB LOCATIONS IN OPEN INFlU AREAS OCEANSPRAY 1 GAL CONT. WITHIN PLANTING INOIAN PLU M 1 GAL CONT. AREAS CALl'ORNIA WAX MYRTLE 1 GAL CONT. FLOWERING RED CURRANT 1 GAL CONT. NOOTKA ROS E 1 GAL CONT. THlt.lBLEBERRY 1 GAL CONT. COMMON SNOWB ERRY 1 GAL CONT. • REPLACEMENT TREES. DECIDUOUS TREES ARE 1" CALIPER AN D CONIFEROUS TREES AT 3· HEIGHT ARE COUNTED />S EOUWALENT FOR I. OF CALIPER REPLACEMENT FOR TREES REMOVED BY PROJECT. 95% REVIEW SU~MITT AL NOT FOR CONSTRUCTION DRA'MNC NO. 54 OF 59 O N E INCH A T ,..ULL SCALE. IF N O T . SCA.LE A C C O RDINGLY : I I I I I:::~(;::;; I· _oL•~«vo•r~•v•L~v-Mrl ~ APPROVED • v{/,.¥'~1~8bN AJ!: ENG!Nff lUNG !"LANNING f NVtftONMf:NTAL SCIENCE& LAKE TO SOUND TRAIL SEGMENT A GREEN RIVE R TRA IL TO NACHES AVE SW MITIGATION PLANTING DETAILS MP7 ~ • JAN 2 2 2Jl7 CITY 01' RfN1::)h\ h.AN:~ING u1v:~Yj\. FINAL GEOTECHNICAL REPORT Lake to Sound Trail Segment A -Black River Bridge Renton, Washington HWA Project No. 2010-100-21 Task 200 Prepared for Parametrix, Inc. um HWA GEOSCIENCES INC. • (;Ctl!Cd111icll} f11s_1l1CCrtll__(:. • J l,rifro.i,::.eoloiy • ( ;('1_lC/Jl'il"t1flllll'l/ti// .°'i't'/"\'i(C.\ ff1m:I uua, HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 Parametrix, Inc. 719 2nd A venue, Suite 200 Seattle, Washington 98104 Attention: Subject: Dear Jenny: Ms. Jenny Bailey FINAL GEOTECHNICAL REPORT LAKE TO SOUND TRAIL SEGMENT A -BLACK RivER BRIDGE RENTON,\VASHINGTON Enclosed is the final geotechnical report for the proposed Black River Bridge on Segment A of the Lake to Sound Trail in Renton, Washington. To stabilize the river banks during a design earthquake event per AASHTO LRFD bridge design specifications, ground improvement treatment is recommended. In particular, we recommend the Deep Mixing Method for ground improvement. The bridge could then be supported on shallow foundations. We appreciate the opportunity of providing geotechnical services on this project. Should you have any questions please do not hesitate to call. Sincerely, H\V A GEOSCIENCES INC. Sa H. Hong, P .E. Principal Geotechnical Engineer ' 21312 30th Drive SE Suite 110 Bothell, WA 98021.7010 Tel: 425.774.0106 Fax: 425.774.2714 www.hwageo.com TABLE OF CONTENTS Page I. INTRODUCTION ............................................................................................................. 1 1.1. PROJECT DESCRIPTION .................................................................................. 1 1.2. SCOPE OF SERVICES AND AUTHORIZATION .................................................... 1 2. FIELD AND LABORATORY INVESTIGATIONS ................................................................... 2 2.1. FIELD EXPLORATJONS .................................................................................... 2 2.2. LABORATORY TESTJNG .................................................................................. 2 3. SITE CONDITIONS ......................................................................................................... 2 3.1. SURFACE CONDffIONS ................................................................................... 2 3.2. GENERAL GEOLOGIC CONIJITIONS ................................................................. 2 3.3. SUBSURFACE CONDITJONS ............................................................................. 3 3.3.1. Soil Stratigraphy ............................................................................ 3 3.3.2. Ground Water ................................................................................ 5 4. CONCLUSIONS AND RFCOMMENDATIONS ...................................................................... 5 4.1. SEISMIC DESIGN ............................................................................................ 5 4.1.1. General .......................................................................................... 5 4.1.2. Regional Seismicity ....................................................................... 5 4.1.3. Seismic Considerations ................................................................. 6 4.1.4. Soil Liquefaction ........................................................................... 7 4.1.5. Ground Fault Hazard ..................................................................... 7 4.2. SLOPE STABILITY EVALUATIONS ................................................................... 7 4.2.1. Static Slope Stability Analyses ...................................................... 8 4.2.2. Pseudo-Static Slope Stability Analyses ......................................... 8 4.2.3. Post-Liquefaction Slope Stability Analyses .................................. 8 4.2.4. Lateral Spreading and Sliding ....................................................... 9 4.2.5. Global Stability after Ground Improvement.. ................................ 9 4.2.5.1. Static Slope Stability Analyses ................................................... 9 4.2.5.2. Pseudo-Static Slope Stability Analyses ....................................... 10 4.3. GROUND IMPROVEMENT TECHNIQUES (GIT) ................................................. I I 4.3.1. Deep Mixing Method .................................................................... 11 4.3.2. Stone Columns .............................................................................. 14 4.3.3. Ground Improvement Verification Tests ....................................... 15 4.4. SJ !ALLOW FOUNDATIONS ............................................................................... 15 4.4.1. Spread Footing Bearing Capacity for Bridge Support ................... 15 4.4.2. Sliding Resistance on Existing Fill for Cast-In-Place Concrete Footings ......................................................................................... 15 4.4.3. Passive Earth Pressure Component of Sliding Resistance for ClP Concrete Footings .......................................................................... 15 4.5. BRIDGE ABUTMENTS, FOOTINGS AND WING WALLS ..................................... 16 4.5.1. Static Lateral Earth Pressures ........................................................ 16 October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 4.5.2. Seismic Lateral Earth Pressures .................................................... 16 4.6. GRAVITY BLOCK WALLS DESIGN .................................................................. 17 4.7. RESISTANCE FACTORS FOR WALLDESIGN ..................................................... 17 4.8. WALL BACKFILL ............................................................................................ 17 4.9. EMBANKMENT SLOPES .................................................................................. 18 4.10. STRUCTURAL FILL MATERIALS AND COMPACTION ...................................... 18 4.11. SITE DRAfNAGE AND EROSlON .................................................................... 19 4.11.1. Surface Water Control.. ............................................................... 19 4.11.2. Erosion Control ........................................................................... 19 4.12. WET WEATHER EARTHWORK ...................................................................... 19 5. CONDITIONS AND LIMITATIONS .................................................................................... 20 6. REFERENCES ................................................................................................................. 23 LIST OFT ABLES Table I Table 2 Table 3 Table 4 Seismic Coefficients for Evaluation Using AASHTO Specifications ........... 7 Global Stability Analyses Results without GIT ............................................. 9 Global Stability Analyses Results after GIT .................................................. 11 Recommended Design Parameters for Gravity Block and Str. E. Walls ....... 17 LIST OF FIGURES (FOLLOWING TEXT) Figure 1 Figure 2 Figure 3 Figure 4 APPENDICES Vicinity Map Site and Exploration Plan Cross Section A-A' Proposed Ground Improvement Areas Appendix A: Field Exploration Figure A-1 Figures A-2 -A-3 Legend of Terms and Symbols Used on Exploration Logs Logs of Boreholes BH-1 and BH-2 Appendix B: Laboratory Testing Figures B-1 -B-4 Particle Size Distribution Test Results Appendix C: Slope Stability Analyses Results Figures C-1 -C-14 Slope Stability Analyses 20 IO. J 00 T200 FR 2 HWA GEOSCIENCES INC. FINAL GEOTECHNICAL REPORT LAKE TO SOUND TRAIL SEGMENT A -BLACK RIVER BRIDGE RENTON, WASHINGTON 1. INTRODUCTION 1.1. PROJECT DESCRIPTION HWA GeoSciences Inc. (HWA) performed a geotechnical study for the proposed Lake to Sound Trail Segment A, Black River Bridge in Renton, Washington. The location of the site and the general project layout are shown on the Vicinity Map (Figure I) and the Site and Exploration Plan (Figure 2), respectively. The purpose of this geotechnical study was to explore and evaluate surface and subsurface conditions at the site and provide recommendations for the geotechnical aspects of the project. The new trail pedestrian bridge will consist of a single-span steel or concrete girder structure over the Black River with a minimum span of approximately 114 feet. The new bridge is being designed in accordance with AASHTO Load and Resistance Factor Design (LRFD) methodology. We understand construction impacts will need to be mitigated to protect the wetland located north of the trail alignment, as well as the Black River channel. 1.2. SCOPE OF SERVICES AND AUTHORIZATION Geotcchnical engineering services were authorized in a subconsultant agreement dated November 7, 20 I 4 and two subsequent amendments. Our scope of work included collecting and reviewing available geotechnical and geologic information in the vicinity of the project site, and performing subsurface explorations at the proposed ends of the bridge span to determine soil and ground water conditions. Our work also included coordinating the field activities with the project team; performing laboratory testing and engineering analyses to develop geotechnical recommendations for the proposed improvements; and preparing draft and final geotechnical reports. The need for additional work was identified during the investigation, in which seismically liquefiable soils were encountered in the borings (unlike the prior borings for the adjacent Monster Road Bridge) and therefore the need for additional analyses to address lateral spreading of the river banks, which would adversely affect the proposed bridge. October 3, 2016 HWA Project No. 2010-100-21 Task 200 2. FIELD AND LABORATORY INVESTIGATIONS 2.1. FIELD EXPLORATIONS Two exploratory borings were drilled on November 10, 2014 and January 6, 2015. Borehole BH-1 was drilled on the north side of the river to a depth of 61 feet, and BH-2 was drilled on the south side to a depth of 86.5 feet. Both borings were drilled utilizing hollow-stem auger methods. The explorations were supervised and logged by a geologist from HWA, who observed the exploratory work on a full time basis. A detailed discussion of the field exploration methodologies and the equipment used is presented in Appendix A, along with the borehole logs and a legend of terms and symbols used on the logs. The exploration locations are shown on Figures 2 and 3. 2.2. LABORATORY TESTING Laboratory tests were performed on selected samples obtained from the borings to characterize relevant engineering and index properties of the site soils. Laboratory tests included determination of in-situ moisture content, and grain size characteristics. The tests were conducted in general accordance with appropriate American Society of Testing and Materials (ASTM) standards. The test results and a discussion of laboratory test methodologies are presented in Appendix B, and/or displayed on the exploration logs in Appendix A, as appropriate. 3. SITE CONDITIONS 3.1. SURFACE CONDITIONS The proposed bridge alignment is located approximately 80 feet (south end) to 230 feet (north end) east of Monster Road Bridge in the City of Renton. The river banks in this area are inclined at approximately 2H: IV. We understand the bridge approaches will be slightly above the original ground surface on the embankments. Both banks are armored with rip-rap rock having maximum diameters ranging from approximately 12 to 24 inches. 3.2. GENERAL GEOLOGIC CONDITIONS The geology of the Puget Sound region includes a thick sequence of glacial and non-glacial soils overlying bedrock. Glacial deposits were formed by ice originating in the mountains of British Columbia (Cordilleran Ice Sheet) and from alpine glaciers which descended from the Olympic and Cascade Mountains. These ice sheets invaded the Puget Lowland at least four times during the early to late Pleistocene Epoch (approximately 150,000 to I 0,000 years before present). The southern extent of these glacial advances was near Olympia, Washington. During periods between these glacial advances and after the last glaciation, portions of the Puget Lowland filled 2010-IOOTIOOFR 2 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 with alluvial sediments deposited by rivers draining the western slopes of the Cascades and the eastern slopes of the Olympics. The most recent glacial advance, the Fraser Glaciation, included the Vashon Stade, during which the Puget Lobe of the Cordilleran Ice Sheet advanced and retreated through the Puget Sound Basin. Existing topography, surficial geology and hydrogeology in the project area were heavily influenced by the advance and retreat of the ice sheet. Surficial geological information for the site area was obtained partly from the published maps, "Geologic Map of the Renton Quadrangle, King County, Washington"' (Mullineaux, 1965) and "Geologic Map of'the Des Moines Quadrangle, King County. Washington"' (Booth and Waldron, 2004 ). The maps indicate that the uplands to the southwest and immediate north consist of Tertiary igneous bedrock predominantly mantled by Pleistocene Vashon till, while the valley floor is covered by alluvial deposits. The bedrock consists of highly jointed and faulted andesite. The till was deposited as a discontinuous mantle of ground moraine beneath glacial ice on the eroded surface of older deposits. Soils defined as Vashon till consist of an unsorted, non-stratified mass of silt, gravel, and sand in varied proportions. The till is of high density/strength due to glacial over-consolidation, and typically has low permeability. The 1965 map, which includes the subject site, indicates the valley floor is covered by alluvium deposited by the White River and Green River, prior to historical diversion of the White River south into the Puyallup in 1906. According to the map this alluvium consists of silt and fine sand at the surface, becoming medium to coarse sand with depth. Black volcanic sand is typical of White River deposits in the valley. The Black River formerly was the outlet for Lake Washington, prior to completion of the Lake Washington Ship Canal in 1917. Very little sediment would be expected to exit the lake; therefore, Black River deposits would consist primarily of reworked sediment of the Cedar River and White River. 3.3. SUBSURFACE CONDITIONS 3.3.1. Soil Stratigraphy Our interpretations of subsurface conditions were based on the results of field explorations, our review of available geologic and geotechnical data, and our general experience in similar geologic settings. It should be noted that in-situ tests performed during drilling, e.g. Standard Penetration Tests represented by N values, identified liquefiable fine sandy silt layers within both borings. For reference, the blow count values recorded during tests are included on the boring logs and are plotted on the penetration resistance chart on each log. Soil density descriptions on the boring logs are based on our observations of soil granularity vs. cohesiveness in addition to the recorded penetration values. 2010-100 T200 FR 3 HWA GEOSC!ENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 In general, the area of the proposed bridge site is underlain by a sequence of layers of recent silty and sandy alluvium deposited by the historical White River and Black River. This alluvium is underlain by glacial till. Bedrock was encountered below the till in BH-1. Suitable bearing material for bridge foundations was encountered at a depth of approximately 45 feet on the north bank (glacial till, over bedrock in BH-1) and at 67 feet at the south bank (glacial till in BH-2). The soil units encountered in the borings are described separately and in more detail below. The conditions are also summarized in Figure 3. Appendix A contains detailed summary logs of subsurface conditions encountered at the individual exploration locations. • Fill-Both borings encountered fill at the ground surface to depths of7.5 feet in BH-1 and approximately 25 feet in BH-2. The fill consisted of medium dense to dense, gravelly silty sand in the upper 4 to 7 feet, then medium dense to loose sandy silt to silty sand with variable gravel content. In BH-2 this latter material had the appearance of alluvium with fine bedding below 17.5 feet; however, a chunk of rubber in the sampler obtained from the sample taken at 20 feet indicated the material was fill to approximately 25 feet. Based on this depth of fill, we speculate that it originated as dredge tailings fill from channel modifications to the Black River. The protective surficial layer of fill on both banks of the river consisted ofloosely placed riprap rocks. • Loose Alluvium -Recent alluvial deposits were encountered beneath the existing fill in both borings. The upper portion of alluvium in BH-1 consisted of fine sandy silt and silty sand. It was typically very loose with N values ranging from Oto 10 and extended from approximately 7.5 to 30 feet deep. In BH-2, loose alluvium consisting of slightly silty sand and sandy gravel was encountered from 25 to 40 feet deep. • Medium Dense to Dense Alluvium -Gravelly, silty sand was encountered below the loose alluvium in BH-1 from approximately 30 to 40 feet. In BH-2, medium dense, clean to slightly silty sand was encountered from approximately 40 to 67 feet, with the upper 5 feet consisting of dense sandy gravel. • Glacial Till -Glacial Till was encountered below the alluvium in both borings, and consisted of unsorted, non-stratified dense to very dense, sandy, gravelly silt to silty, gravelly sand. • Bedrock -Bedrock was encountered at a depth of approximately 55 feet in borehole BH-1 at the north bank, but was not encountered within BH-2 at the south bank. This is also a pile foundation bearing strata at the site. The bedrock consisted of fractured basalt, becoming less weathered and stronger with depth. 20 I 0-100 T200 FR 4 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 3.3.2. Ground Water Ground water was observed during drilling in both borings, at depths of approximately 13.5 and 19 feet below the existing ground surface at BH-1 and BH-2, respectively. Because of relatively high permeability of the fill soils and silty sand, it is expected that ground water levels will be reflective of river level. The observed ground water levels during drilling are indicated on the boring logs and on Figure 3. The ground water conditions reported on the exploration logs are for the specific dates and locations indicated and, therefore, may not necessarily be indicative of other times and/or locations. Furthermore, it is anticipated that ground water conditions will vary in response to other factors such as rainfall, time of year, local subsurface conditions, and other factors. 4. CONCLUSIONS AND RECOMMENDATIONS The possibility of lateral spreading of the riverbanks due to soil liquefaction during a design seismic event became evident after completion of the subsurface exploration program. This was in contradiction to conditions observed by others in borings conducted for the adjacent Monster Road Bridge (Golder, 1995). The alluvium encountered in our borings was very loose to medium dense, as opposed to medium dense to dense as encountered in the Monster Road Bridge borings. Our analyses indicate the looser soils will liquefy during a design-level earthquake, resulting in lateral spreading of the riverbanks. Therefore, we recommend the bridge abutment areas be stabilized through Ground Improvement Techniques (GIT). Geotechnical recommendations are provided below for bridge seismic design, ground improvement to minimize potential liquefaction and lateral spreading damage, slope stability, bridge foundations, bridge abutments and earthwork, and site drainage. 4.1. SEISMIC DESIGN 4.1.1. General Based on the LRFD Bridge Design Specifications, 7th Edition (AASHTO, 2014 ), potential secondary effects of earthquakes on the proposed bridge include soil liquefaction, lateral spreading, seismically-induced settlement, and ground faulting. The following sections provide additional discussions and recommendations pertaining to these seismic issues for use in design of the bridge. 4.1.2. Regional Seismicity The seismicity of northwest Washington is not as well understood as other areas of western North America. Reasons for this include: (I) incomplete historical earthquake records; (2) deep and relatively young glacial deposits and dense vegetation which obscure surface expression of 201 O* 100 T200 FR 5 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 faults (Hall and Othberg, 1974); and (3) the distribution of recorded seismic epicenters is scattered and does not define map-able fault zones (Gower, et al., 1985). Historical records exist, however, of strong earthquakes with local Modified Mercalli Intensities up to VIII (indicative of structural damage such as cracked walls and fallen chimneys). Since the l 850's, 28 earthquakes of Magnitude 5 (Richter Scale) and greater have reportedly occurred in the eastern Puget Sound and north-central Cascades region. Five events may have exceeded Magnitude 6.0. Researchers consider the North Cascades earthquake of 1872, centered near Lake Chelan, the strongest (Magnitude 7.4) historical earthquake in the region. Earthquakes of Magnitude 7.2 occurred in central Vancouver Island in 1918 and 1946. The most significant recent event, the Nisqually Earthquake, occurred on February 28, 2001, near Olympia and had a magnitude of 6.8. Other significant historical earthquakes in the region include a 1949 event near Olympia (Magnitude 7 .2), and a 1965 event centered between Seattle and Tacoma (Magnitude 6.5). These latter three were intraplate Benioff Zone earthquakes, occurring at a depth of about 30 miles within the descending subducted oceanic plate. Potential sources of earthquakes that may be significant to the site include: (I) the Cascadia subduction zone, along which the Juan de Fuca oceanic plate is being thrust under the North American plate; and (2) shallow crustal faults that may generate earthquakes in the site vicinity (McCrumb et al., 1989). The latest subduction zone earthquake in the Pacific Northwest had been determined from Japanese tsunami records to have occurred in 1700, and recent offshore sedimentological research has indicated that the entire length of the subduction zone slipped at once, which would result in an earthquake of around Magnitude 9.0. 4.1.3. Seismic Considerations Earthquake loading for the proposed Black River bridge structure was developed in accordance with Section 3.4 of the AASHTO Guide Specifications for LRFD Bridge Design, 2014. For seismic analysis, the Site Class is required to be established and is determined based on the average soil properties in the upper I 00 feet below the ground surface. Based on our explorations and understanding of site geology, it is our opinion that the proposed alignment is underlain by soils classifying as Site Class D. Table I presents recommended seismic coefficients for use with the general procedure described in the guide (AASHTO, 2014), which is based upon a design event with a 7 percent probability of exceedance in 75 years (equal to a return period of 1,033 years). Ground motions for the site are based on probabilistic earthquake hazard mapping efforts including those conducted by the United States Geological Survey. Accordingly, a Seismic Design Category D, as given by the guide (AASHTO, 2014) should be used. 2010-IOOT200 FR 6 HWA GEOSCIENCES !NC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 T bl 1 S . . C ffi . a e e1sm1c oe 1c1ents i E or va uatmn U. AASHTOS "fi sm2 ,pec1 1catmns Peak Spectral Spectral Site Amplification Site Ground Bedrock Bedrock Coefficients Design Acceleration Class Acceleration Acceleration Acceleration Coefficient at 0.2 sec at 1.0 sec As, (g) PGA,(g) S..(g) s,.(g) F,,. Fa F. D 0.446 0.993 0.331 1.05 I. I 1.74 0.470 4.1.4. Soil Liquefaction Liquefaction occurs when saturated and relatively cohesionless soil deposits such as silts, sands, and fine gravels temporarily lose strength as a result of earthquake shaking. Primary factors controlling the development of liquefaction include intensity and duration of strong ground motion, characteristics of subsurface soils, in-situ stress conditions and the depth to ground water. Potential effects of soil liquefaction include temporary loss of bearing capacity and lateral soil resistance, and liquefaction-induced settlement and deformations, with concomitant potential impacts on the proposed bridge and embankment fills. Based on the saturated, loose nature of the alluvium noted below fill in BH-1 and BH-2, liquefaction will be a design consideration for this project. Based on the methods by Seed and Idriss ( I 971) and Ishihara and Yoshimine ( I 992), liquefaction of the loose alluvium/fill layer, 20 feet thick, below the upper medium dense fill will liquefy during an earthquake with PGA=0.446g and Mw=7.5. 4.1.5. Ground Fault Hazard The Seattle and Tacoma Faults are probably the most serious earthquake threat to the populous Seattle-Tacoma area. The Black River Bridge site is located between these faults. A study in 2005 (EERl and Washington Military Dept.) of bridge vulnerability estimated that a magnitude 6.7 earthquake on the Seattle Fault would damage approximately 80 bridges in the Seattle- Tacoma area, whereas a magnitude 9.0 subduction event would damage only around 87 bridges in all ofwestem Washington. The same study also found that with failure of just six bridges (the minimum damage from a Benioff M 6.5 event) there could be at least $3 billion lost in business revenue alone. Seismic retrofitting would likely reduce damage to key bridges. 4.2. SLOPE STABILITY EVALUATIONS The proposed pedestrian bridge abutments are to be constructed above the top of the river bank slopes. The stability of these slopes was evaluated using limit-equilibrium methods utilizing the computer program SLIDE 5.0 (Rocscience, 2013). Limit equilibrium methods consider force (or moment) equilibrium along potential failure surfaces. Results are provided in terms of a factor of 2010-100 T200 FR 7 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 safety, which is computed as the ratio of the summation of the resisting forces to the summation of the driving forces. Where the factor of safety is less than 1.0, instability is predicted. With limit equilibrium, the shear strength available is assumed to mobilize at the same rate at all points along the failure surface. As a result, the factor of safety is constant over the entire failure surface. 4.2.1. Static Slope Stability Analyses The static factors of safety calculated along Cross Section A-A', Figure 3, was evaluated with Spencer's method, Janbu's Simplified method, and Bishop's Simplified method with the observed site conditions. The factor of safety of the slope at the southern abutment, under static loading, is approximately 1.26 and for the northern abutment is approximately 1.1, as shown on Figures C-1 and C-4 of Appendix C, respectively. These analyses indicate that the factor of safety is slightly greater than 1, which means that the slopes are marginally stable under the static condition with the current condition of the slopes. 4.2.2. Pseudo-Static Slope Stability Analyses Cross Section A-A' was evaluated using pseudo-static methods to evaluate the response of the slope under earthquake loading prior to the onset of liquefaction. Spencer's, Janbu's Simplified, and Bishop's Simplified methods were used in this evaluation. Pseudo-static slope stability analyses model the anticipated earthquake loading as a constant horizontal force applied to the soil mass. For our analyses, we used a horizontal seismic coefficient of 0.235g, which is one- half of the design acceleration coefficient (As, in Table I). Pre-liquefaction strengths were used for all materials in this analysis. The results of these analyses indicate a factor of safety of approximately 0.65 and 0.62, for the southern and northern abutments, respectively, as shown in Figures C-2 and C-5 of Appendix C. These analyses indicate that slope instability is likely to occur during the design seismic event, prior to the onset of liquefaction. As a factor of safety less than 1.0 was calculated, we expect the existing slopes to undergo lateral spreading upon the onset of liquefaction. 4.2.3. Post-Liquefaction Slope Stability Analyses Additional stability analyses were completed for the slopes depicted in Cross Section A-A' to determine the response of the slopes after the onset of liquefaction. The post-liquefaction residual shear strengths for the liquefiable soils were used to model the anticipated loss of shear strength during a seismic event. The results of these analyses indicate a factor of safety of approximately 0.31 and 0.19, for the southern and northern abutments, respectively, as shown in Figures C-3 and C-6 of Appendix C, respectively. As a factor of safety less than 1.0 was 20 JO. J 00 T200 FR 8 HWA GEOSC!ENCES INC. October 3. 2016 HWA Project No. 2010-100-21 Task200 calculated, we expect the existing slopes to undergo large lateral spreading upon the onset of liquefaction. A summary of the anticipated factor of safety for global stability at the abutments are provided below in Table 2. T able 2. Global Stability Analyses Results Without GI T Factor of Safety South Side North Side Static 1.26 I. I 0 Pseudo-Static 0.65 0.62 Post Liquefaction 0.31 0.19 4.2.4. Lateral Spreading and Sliding Lateral spreading occurs cyclically when the horizontal ground accelerations combine with gravity to create driving forces which temporarily exceed the available strength of the soil mass. This is a type of failure known as cyclic mobility. The result of a lateral spreading failure is horizontal movement of the partially liquefied soils and any overlying crust of non-liquefied soils. We would expect displacements associated with lateral spreading to be very large at this site. Bartlett and Youd ( 1992) used a large data base of lateral spreading case histories and developed an empirical formula. According to the research, we calculated a yield acceleration (ay=0.2g) by means of a trial and error method for the existing bank slope (2H: IV) and Newmark's sliding block slope stability analyses. When an earthquake magnitude Mw=7 occurs, the estimated lateral spreading ranges from about 24 to 134 inches depending upon assumed epicenter distances, 60 km (Tacoma Fault) and 6 km (Seattle Fault) away, respectively. Although the results vary widely, the analyses demonstrate that large lateral spreading is likely during a significant seismic event. To mitigate these liquefiable soil conditions and lateral spreading, we recommend that the strength of the slopes be increased by in-situ ground improvement techniques (GIT). See Section 4.3 for a discussion of GIT methods: Deep soil mixing method (DMM) and Stone column treatment (SC). 4.2.5. Global Stability after Ground Improvement 4.2.5.1. Static Slope Stability Analyses The static factors of safety calculated along Cross Section A-A' were evaluated with Spencer's method, Janbu's Simplified method, and Bishop's Simplified method assuming ground improvement was performed per Section 4.3. 2010-100 T200 FR 9 HWA GEOSClENCES !NC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 The factor of safety of the slope at the southern abutment, under static loading assuming stone columns as GIT, is approximately 1.30 and for the northern abutment is approximately 1.24, as shown on Figures C-7 and C-8 of Appendix C. These analyses indicate that the factor of safety increases slightly after the application of stone columns as GIT. These factor of safety magnitudes confirm that the composite shear strength properties achieved from the utilization of stone columns as GIT are not adequate for the stabilization of the slope. The factor of safety of the slope at the southern abutment, under static loading assuming deep soil mixing (DMM) as GIT, is approximately 3.5 and for the northern abutment is approximately 2.5, as shown on Figures C-9 and C-10 of Appendix C. These analyses indicate that the factor of safety increases significantly after the application of deep soil mixing (DMM) and that global slope instability is not likely to occur under static loading conditions. 4.2.5.2. Pseudo-Static Slope Stability Analyses Cross Section A-A' was evaluated using pseudo-static methods to evaluate the response of the slope under earthquake loading prior to the onset of liquefaction, after the application of GIT. Spencer's, Janbu's Simplified, and Bishop's Simplified methods were used in this evaluation. Pseudo-static slope stability analysis model the anticipated earthquake loading as a constant horizontal force applied to the soil mass. For our analyses, we used a horizontal seismic coefficient of0.235g, which is one-half of the design acceleration coefficient (As). Pre- liquefaction strengths were used for all materials in this analysis. The results of these analyses assuming stone columns as GIT indicate a factor of safety of approximately 0.77 for the southern abutment and 0.68 for the northern abutment, as shown in Figures C-11 and C-12 of Appendix C. This indicates that slope instability is likely during a seismic event, prior to the onset of liquefaction. As a factor of safety less than 1.0 was calculated, we expect the SC-treated slopes to undergo minor lateral spreading (non-catastrophic) upon the onset of liquefaction. These factor of safety magnitudes confirm that the composite shear strength properties achieved from the utilization of stone columns as GIT are not adequate for the stabilization of the slope. The results of these analyses assuming deep soil mixing (DMM) as GIT indicate a factor of safety of approximately 1.6 for the southern abutment and l .2 for the northern abutment, as shown in Figures C-13 and C-14 of Appendix C. The results shown in Figures C-13 and C-14 are for a sliding surface passing beneath the deep soil mixing depth. Additional to these analyses, we evaluated potential sliding surfaces that pass through the deep mixed zone and shallow sliding surfaces as is recommended by FHW A design manual for deep soil mixing (FHW A, 2013). These analyses indicate that global slope instability is not likely during the design seismic event. The summary of the stability analyses is summarized in Table 3, below. 20 IQ. 100 T200 FR 10 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 Table 3. Global Stabilit Analvses Results after GIT Factor of Safety South Side North Side SC DMM SC DMM Static After GIT 1.3 3.5 1.2 2.5 Pseudo-Static After GIT 0.77 1.6 0.68 1.2 4.3. GROUND IMPROVEMENT TECHNIQUES (GIT) The bridge foundations should be designed to withstand liquefaction-induced lateral and down- drag loading as well as liquefaction-induced lateral spreading. To mitigate liquefaction conditions and densify the loose sand/silt layer noted below the fill, we recommend ground improvement techniques (GIT) be applied. Based on our analyses, we recommend the deep mixing method (DMM). Slope stability analyses of modeled conditions post-application of DMM present factors of safety greater than 1.0 for static and pseudo-static conditions for both abutments. Additionally, the deep mixing method reduces the potential of adverse construction impacts to the river, in comparison to stone columns. The particular methods are described in Sections 4.3.1 and 4.3.2 below. The section on stone columns is included for comparison, but we recommend against using stone columns due to inadequate factors of safety against static slope instability and lateral spreading, and greater (and partly unmitigatable) construction impacts to the river and adjacent wetland. 4.3.1. Deep Mixing Method The deep mixing method (DMM) is an in-situ method in which the physical properties of weak soils are improved by mechanically mixing in wet or dry cement. Specialized augers and mixing paddles are used to mix the soil in a column. DMM is achieved by a rotating motion with no vibration applied, such that accidental slope failure during DMM construction will not be likely. We recommend 4-foot diameter columns. Rows of overlapping soil mixed columns oriented in the direction of the possible soil movement (perpendicular to river) would resist sliding and lateral spreading. As a result of DMM, the treated rows will behave like shear walls at the bridge abutments to resist lateral movement. The rows of overlapping columns should be spaced with a 2-foot gap in between rows (6 feet center to center). The DMM treatment area should begin above the Ordinary High Water Mark (OHWM) and extend to 4 feet behind ( opposite the river from) each abutment. The width of treatment area should be 16 feet, making 3 rows of overlapping columns (see Figure 4). The columns should overlap at least 1 foot along each row. The ground improvements should be conducted in the dry summer months to take advantage of lower water levels. The treatment depths should extend to EL -2 and EL -14 at the north and south banks, respectively. The loose alluvium to be treated is about 15 to 23 feet thick, extending to depths of approximately 32 feet below ground surface on the north side and 42 feet 2010-l00T200 FR 11 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 below ground surface on the south side. These depths include a 2-foot penetration into the medium dense sand layer. Installation of the first columns should begin just above OHWM and progress away from the river. A temporary three-sided sheet pile containment wall would be necessary for each abutment area, along OHWM and perpendicular to the bank along the sides of the GIT areas as shown on Figure 4. The sole purpose of the containment wall is to prevent any wet spoils generated from the GIT operations from entering the river. This wall should be designed by the contractor who will be performing the GIT. We anticipate the sheet pile wall would be embedded approximately IO feet with a stickup of about 7 feet. We recommend a 5-foot setback distance from the sheet pile wall to the DMM columns. We recommend that DMM replacement ratio per volume be on the order of 40 percent. The cemented soil columns provide high shear strength to resist lateral movements. Typical DMM unconfined compressive strength (qam. spec) within columns ranges from I 00 to 300 psi depending upon the sand/silt contents. We recommend a 28-day unconfined compressive strength (UCS) of qu= 150 psi be achieved by the contractor for 90% of all cores obtained and tested after DMM completion and wet samples taken during DMM. The specialty contractor should obtain wet samples at every 5 feet in selected columns (at least one per day) and the samples should be tested at 7, 14, 28 and 56 days. The specialty contractor should provide drilled core samples at two DMM columns each at the south and north abutment per the owner's designation. The specialty contractor should submit laboratory cement slurry mix-design with the unconfined compressive strength. Medium dense to dense fill soils were encountered from the surface to depths of 7.5 feet to 17 feet, at the north and south bank, respectively. We recommend that this surface crust (Fill) be predrilled for each DMM column in order to facilitate the deep mixing method. The existing river banks are armored with riprap stones which should be removed prior to pre-drilling. The cost associated with predrilling, removal and restoration ofriprap on the slopes should be included for estimating the cost of the project. Riprap restoration is still needed after DMM because untreated areas between DMM will be vulnerable to erosion. DMM will bring up wet, silty and cementitious spoils to the surface from the mixing process. This will tend to flow towards the river and will need to be contained by means of a short sheet pile wall and lined with erosion mats and geotextile fencing. For the extent of ground improvement proposed, a local specialty contractor estimated about 1,500 cubic yards of soil- cement spoils would need to be hauled off for disposal. However, this amount shall be re- evaluated by each contractor based on their equipment and experience for their actual bidding. We recommend that shallow spread footings resting on the deep soil mixed columns be used to support the bridge (see Section 4.4). 2010-100 T200 FR 12 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 DMM Construction Considerations The existing rip-rap will be an impediment to driving sheet piles for the temporary containment wall, as well as to drilling for deep soil mixing. The uncertainty of rip-rap size and thickness, and therefore the relative difficulty of driving/ drilling vs. excavating out the rip rap, poses a significant cost risk to the project. The risk can be greatly reduced by evaluating the rip-rap size and thickness in advance, so that the cost of removing the rip-rap can be estimated for budgeting, and contractors can bid for rip-rap removal on an even basis. All rip-rap within the proposed treatment areas would need to be removed, as selective removal for each DMM shaft would remove most of the rip-rap anyway but at greater effort than removing all. The rip-rap size and thickness should be investigated during design with a trackhoe having at least a 30-foot reach. The contract should state that rip-rap should be removed prior to driving sheets and drilling for deep soil mixing. It will need to be done in such a way as to avoid increasing the turbidity of the river. Assuming removal of rip-rap will be from OHWM and up, the work should not be done during high tides, e.g. a buffer between the excavation work and river level should be maintained. The depth limitation of DMM is about 130 feet. The intended ground improvement depths, in the range of 30 to 40 feet, are well within the range of maximum depth. The abutment work space needs to be large enough to accommodate a large crane, other auxiliary equipment, concrete truck, and pump truck. Adjacent property ownership and land use (wetland, river and narrow foot print of embankment) constrain the available work areas. The north side work area is particularly constrained to a narrow width at the proposed bridge site, but in our opinion and based on conversations with a ground improvement contractor, there is adequate room for construction. The crane would operate from the level area above the bank crest. Based on the presence of medium dense granular fill at the surface to a depth of 7 feet, it does not appear that the north side would require ground mitigation for crane support. However, timber crane mats may be desirable. The contractor should provide a submittal regarding equipment type and size, support, and slope stability evaluations, as well as general staging procedures. Potential turbidity impacts to the river include siltation from removing rip-rap close to the water line, and runoff from spoils with cement from wet-mixing. These can be mitigated by installing a sheet pile wall on each river bank just above OHW, lined with visquene, to catch loosened soils and cement and allow for removal with heavy equipment for disposal off site. The walls would need to be embedded IO feet and stickup approximately 7 feet. The purpose of the sheet pile walls is to contain drilling spoils and stonnwater runoff only; it would not stabilize the slope. Even with predrilling of the columns through the medium dense upper soils, spoils consisting of excess soil and cement slurry will come to the ground surface and need to be contained and disposed of continuously as DMM progresses. The volume of material could potentially be up to, or greater than, the cement replacement volume, e.g. 40 percent of shaft volume. 2010-100 T200 FR 13 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 Assuming a 4-foot diameter for DMM columns, the lowermost columns would need to be at least 5 feet from the sheet pile wall to prevent destabilization of the wall. By standard procedure, adjacent column rows would not be installed on the same day, to allow for curing of the cement before installation of adjacent rows. Constraints to installation sequencing should be provided to bidders, who will need to provide submittals regarding means and methods including sequencing. After all DMM columns are installed and rip-rap reestablished on the banks, the sheet pile walls would be removed. Installation and removal of the sheet pile walls would be conducted with a crane-suspended vibratory hammer, such that the piles can be installed on a slope distant from where equipment actually sits. We recommend that the wet rotary method be specified, and the wet jet method prohibited. With the wet jet method, which utilizes high-pressure water during drilling and injection of cement slurry, there is a higher risk of turbid water eruption at the ground surface or within the river. Also, slope stability could be compromised during installation of the lower columns. We do not anticipate impacts to ground water flow from DMM. Alkalinity increases will be temporary during cement treatment and curing of soil columns. 4.3.2. Stone Columns The stone column (SC) method is a method by which vertical columns are made of compacted aggregate extending through a deposit of loose soil, and result in increased shear resistance of the slope and relief of pore-water pressure during the design earthquake event. Using the dry method, SCs are installed with a vibratory probe and a deep stone feed tube, forcing the aggregate radially into the loose soil zones, compacting the stone as well as any granular zones formed in the surrounding soil. Typical diameters of stone columns are 2 to 4 feet. Stone columns provide dissipation of excess pore pressure during strong shaking and the treated soil layer will not liquefy. As indicated in the previous sections of slope stability analyses, SC would not completely eliminate the slope instability problem during the design earthquake event, but it would prevent liquefaction of the loose alluvium layer, and thereby reduce lateral spreading (Bohn and Lambert, 2013). The wet, top-feed method can create "geysers" of silty water coming up from the ground in random, unwanted locations. If constructed in an improper order, e.g. progressing toward the river instead of away, then vibrations may cause local liquefaction and accidental embankment failure. Based on the higher risks of slope instability as well as turbidity impacts to the river and adjacent wetlands, we recommend against using the SC method. 20 I 0-100 T200 FR 14 HWA GEOSC!ENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 4.3.3. Ground Improvement Verification Tests DMM Verification Tests After DMM treatment, two borings should be made at each abutment site with core samples retrieved for unconfined compressive strength tests. The average strength should be approximately 150 psi and the minimum strength 75 psi. The geotechnical engineer ofrecord should evaluate the DMM strength improvement. The boreholes should be backfilled with grout after coring. 4.4. SHALLOW FOUNDATIONS Shallow strip and square footings, as recommended below, can be used to support the bridge structure after DMM treatment is implemented. 4.4.1. Spread Footing Bearing Capacity for Bridge Support Shallow strip and square footings supporting the bridge abutment and bridge approach retaining walls on level ground that has been treated with DMM per the strength improvement recommendations specified above can be designed with a net bearing capacity ( qn) of 12,000 psf and on sloping ground (2H: l V) 5,000 psfwith a 2-foot minimum width. A resistance factor, <pb = 0.5, should be applied for the design. All footing areas should be treated with DMM. Total settlement under the load will be one inch or less. The depths of the footings should not be less than 18 inches below ground surface for frost protection. Footings located on slopes should have a minimum embedment depth of 36 inches. The resistance factor for the extreme and service cases should be 1.0. While earthwork and concrete work for the footings can begin as soon as the next day after completion of ground improvement, we recommend that 14 days be allowed for curing of the DMM columns before installation of the bridge superstructure. 4.4.2. Sliding Resistance on Existing Fill for Cast-In-Place Concrete Footings The friction coefficient at the base of footings should be 0.4. Resistance Factor <p, =0.8 should be used. The resistance factor for the extreme and service cases is 1.0. 4.4.3. Passive Earth Pressure Component of Sliding Resistance for CIP Concrete Footings The passive earth pressures for static and dynamic cases shall be estimated per Sections 4.5.1 and 4.5.2, respectively. 2010-100 T200 FR 15 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 4.5. BRIDGE ABUTMENTS, FOOTINGS AND WING WALLS 4.5.1. Static Lateral Earth Pressures Lateral at-rest earth pressures used for design of bridge abutments under static loading conditions should be equivalent to that generated by a fluid weighing 55 pcf, assuming the tops of the abutments are restrained from lateral movement. An equivalent fluid unit weight of 35 pcf should be utilized if the tops are free to rotate (i.e. active case). The above recommendations assume a level backslope behind the wall, and that properly compacted, well-drained granular fill is placed as backfill behind the abutment walls. Traffic surcharge loads should also be included in the abutment design. The traffic surcharge should be multiplied by the active earth pressure coefficient (ka) of0.27 for a wall free to rotate, or the at-rest earth pressure coefficient (ko) equal to 0.43 for a wall restrained from movement at its top. Lateral loads at bridge abutments can be resisted by passive resistance of buried structural elements. Passive resistance may be evaluated using an equivalent fluid density of 300 pcf for structural elements cast neat against the wall on the levelled ground surface. The upper two feet should be ignored for passive resistance. The soil in front of the wall must also be level for a distance of at least twice the depth of embedment below the ground surface. If the slope geometry does not meet these requirements, we recommend the passive resistance be ignored when evaluating lateral restraint. In addition, structural elements will need to be able to move sufficiently to generate the full passive resistance. The lateral movement required to generate 100 percent of the passive pressure is a function of the type of soil bearing against the footing and the thickness of the footing. We estimate structural elements founded against undisturbed structural fill would need to move laterally a distance of0.02H, to generate 100 percent of the passive pressure, where H represents the height of the structural element. The AASHTO LRFD Bridge Design Specifications state that surveys of the performance of bridges indicate that horizontal abutment movement less than 1.5 inches can usually be tolerated by bridge superstructures without significant damage. It appears therefore that, for abutments with heights not exceeding 6.25 feet, full passive resistance can be mobilized by allowing the abutment to move laterally a distance equal to 0.02H. 4.5.2. Seismic Lateral Earth Pressures During a seismic event, seismic earth pressures acting on bridge abutments should be equivalent to that generated by a fluid weighing 55 pcf, assuming the tops of the abutments are able to deflect at least 1 to 2 inches during seismic loading. To determine the lateral earth pressure under seismic loading, the Mononobe-Okabe analysis was utilized, as formulated by Richards and Elms (I 992). For computation of the lateral seismic earth pressure a seismic horizontal coefficient (kh) of0.235 was used. This fluid pressure should be used in place of the earth 20JQ.JOOT200 FR 16 HWA GEOSCJENCES INC. October 3, 2016 HWA Project No. 20 l 0-100-2 l Task 200 pressure recommended for use under static loading. Note that the current AASHTO code recommends the resultant of the seismic earth pressures to be applied at l/3*h. 4.6. GRAVITY BLOCK WALLS DESIGN We understand that portions of the trail will be supported by either gravity block walls or structural earth walls (SEWs). We assume that the gravity block and SEW walls will conform to one of the current WSDOT pre-approved systems. and that the wall suppliers will design the walls for internal stability. The retaining walls should be designed in accordance with AASHTO Standard Specifications for Highway Bridges. We recommend that each of the walls be designed using the parameters presented in Table 4. Table 4. Recommended Desi2n Parameters for Gravity Block Walls and Structural Earth Walls Soil Properties Wall Backfill Retained Soil Foundation Soil Unit Weight (pct) 140 140 140 Friction Angle (deg) 36 36 36 Cohesion (pst) 0 0 0 AASHTOLoad AASHTO Load Group Group I VII (EP+EQ) (EP+LL) Ultimate Bearing Capacity (pst) 5,000 5,000 Acceleration Coefficient (g) NIA 0.47 4. 7. RESISTANCE FACTORS FOR WALL DESIGN The resistance factors for the Strength Limit State should be obtained from Table 11.5.7-1 of the AASHTO LRFD Bridge Design Specifications (AASHTO, 2014) for the appropriate wall type. Resistance factors for the Extreme Event Limit State are provided in Section 11.5.8 also in the LRFD Bridge Design Specifications. 4.8. WALL BACKFILL Abutment wall design and construction should be in accordance with applicable WSDOT Standards. Wall backfill materials should consist of Gravel Backfill for Walls (WSDOT 9- 03.12(2)), or Gravel Borrow (WSDOT 9-03.14), as described in the WSDOT Standard Specifications (WSDOT, 2014). Placement and compaction of fill behind walls shall be in accordance with WSDOT 2-09.3( I) E, with the exception that the compaction standard referenced in Section 2-03.3(14) D should be Modified Proctor, per ASTM D 1557. 2010-100 T200 FR 17 HWA GEOSC!ENCES ]NC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 Wall drainage systems should also be designed and constructed in accordance with the WSDOT Standard Specifications. Provisions for permanent control of subsurface water should at a minimum consist of a perforated drain pipe behind and at the base of the wall, embedded in clean, free-draining sand and gravel. The base of the drain pipe should be a minimum of 12 inches below the base of the adjacent ground surface at the toe of the wall. The drain pipe should be graded to direct water away from backfill and subgrade soils and to a suitable outlet. 4.9. EMBANKMENT SLOPES We recommend that the planned compacted fill slopes or bank slopes be constructed/restored no steeper than 2H: IV (Horizontal:Vertical). For fill slopes constructed at 2H: IV or flatter, and comprised of fill soils placed and compacted as structural fill as described above, we anticipate that adequate factors of safety against global failure will be maintained. Measures should be taken to prevent surficial instability and/or erosion of embankment material. This can be accomplished by conscientious compaction of the embankment fills all the way out to the slope face, by maintaining adequate drainage, and planting the disturbed slope face with vegetation as soon as possible after construction. To achieve the specified relative compaction at the slope face, it may be necessary to overbuild the slopes several feet, and then trim back to finish grade. In our experience, compaction of.slope faces by "track-walking" is generally ineffective and is, therefore, not recommended. Even after ground improvement treatment, riprap rocks should be installed on the banks from the toe level of the slopes to the design flood level of the river. The riprap rocks removed from the slopes can be re-used. Riprap rocks ( 18" minus in diameter) meeting WSDOT 9-13 and 9- 13.4(2) should be underlain by a 12-inch layer of 4-inch minus Quarry Spalls, per WSDOT 9- 03.6. If rip-rap is not allowed by the agencies, bioengineered erosion protection should be incorporated into the slope restoration, the design of which is beyond our current scope of work. 4.10. STRUCTURAL FILL MATERIALS AND COMPACTION In our opinion, the existing fill on site will not be suitable for use as structural fill. Imported structural fill should consist of relatively clean, free draining, sand and gravel conforming to the Gravel Borrow specification, Section 9-03.14 (Gravel Borrow) of the 2014 WSDOT Standard Specifications. If earthwork is performed during extended periods of wet weather or in wet conditions, the structural fill should conform to the recommendations provided below in Section 4.9, Wet Weather Earthwork. In general, the backfill should be placed in horizontal lifts and compacted to a dense and unyielding condition, and at least 95 percent of its maximum dry density, per test method ASTM D 1557. The thickness of loose lifts should not exceed 8 inches for heavy equipment compactors and 4 inches for hand operated compactors. 2010-100T200 FR 18 HWA GEOSCIENCES INC. October 3. 2016 HWA Project No. 2010-100-21 Task200 The procedure to achieve the specified minimum relative compaction depends on the size and type of compaction equipment, the number of passes, thickness of the layer being compacted, and on soil moisture-density properties. We recommend that the appropriate lift thickness, and the adequacy of the subgrade preparation and materials compaction, be evaluated by a representative of the geotechnical consultant during construction. A sufficient number of in-place density tests should be performed as the fill is being placed to determine if the required compaction is being achieved. 4.11. SITE DRAINAGE AND EROSION 4.11.1. Surface Water Control Surface runoff can be controlled during construction by careful grading practices. Typically, these include the construction of shallow, upgrade, perimeter ditches or low earthen berms and the use of temporary sumps to collect runoff and prevent water from damaging exposed subgrades. Also, measures should be taken to avoid ponding of surface water during construction. The use of Ground Improvement Techniques will require the use of a sheetpile containment wall for each treatment area during GIT construction. Permanent control of surface water should be incorporated in the final grading design. Adequate surface gradients and drainage systems should be incorporated into the design such that surface runoff is directed away from structures and pavements and into swales or other controlled drainage devices. 4.11.2. Erosion Control In our opinion, erosion at the site during construction can be minimized by implementing the recommendations presented in Wet Weather Earthwork, Section 4. I 2, and by judicious use of straw bales, silt fences and plastic sheets. The erosion control devices should be in place and remain in place throughout site preparation and construction. Potential problems associated with erosion may also be minimized by establishing vegetation within disturbed areas immediately following grading operations. Vegetation with deep penetrating roots is the preferred choice, since the roots tend to maintain the surficial stability of slopes by mechanical effects and contribute to the drying of slopes by evapotranspiration. 4.12. WET WEATHER EARTHWORK The on-site fill is considered moderately moisture sensitive and may be difficult to traverse with construction equipment during periods of wet weather or wet conditions. Furthermore, the near- surface soils may be difficult to compact if their moisture content significantly exceeds the optimum. General recommendations relative to earthwork performed in wet weather or in wet conditions are presented below. 20 I 0-100 T200 FR 19 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 • Earthwork should be performed in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. The size and type of construction equipment used may have to be limited to prevent soil disturbance. Under some circumstances, it may be necessary to excavate soils with a backhoe to minimize subgrade disturbance that may be caused by equipment traffic. • Material used as structural fill should consist of clean granular soil with less than 5 percent passing the U.S. Standard No. 200 sieve, based on wet sieving the fraction passing the %-inch sieve. The fine-grained portion of the structural fill soils should be non-plastic. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. • The ground surface within the construction area should be sealed by a smooth drum vibratory roller, or equivalent, and under no circumstances should soil be left uncompacted and exposed to moisture. • Excavation and placement of structural fill material should be performed under the full-time observation of a representative of the geotechnical engineer, to determine that the work is being accomplished in accordance with the project specifications and the recommendations contained herein. • Bales of straw and/or geotextile silt fences should be strategically located to control erosion and the movement of soil. 5. CONDITIONS AND LIMITATIONS We have prepared this report for use by Parametrix, Inc. and King County in design of a portion of this project. The report and any other applicable geotechnical data should be provided in its entirety to prospective contractors for their bidding or estimating purposes, but our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Experience has shown that subsurface soil and ground water conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by a geotechnical study. If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein, HWA should be notified for review of the recommendations of this report, and revision of such if necessary. If there is a substantial lapse of time between the submission of this report and the start of construction, or if conditions have changed due to construction operations at or near the site, it is 2010-100T200 FR 20 HWA GEOSCJENCES INC. October 3, 2016 HWA Project No. 2010-100-21 Task 200 recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. This report is issued with the understanding that the information and recommendations contained herein will be brought to the attention of the appropriate design team personnel and incorporated into the project plans and specifications, and the necessary steps will be taken to verify that the contractor and subcontractors carry out such recommendations in the field. Within the limitations of scope, schedule and budget, HWA attempted to execute these services in accordance with generally accepted professional principles and practices in the fields of geotechnical engineering and engineering geology in the area at the time the report was prepared. No warranty, express or implied, is made. The scope of our work did not include environmental assessments or evaluations regarding the presence or absence of wetlands, hazardous substances in the soil, or surface water at this site. This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and cannot be responsible for the safety of personnel other than our own on the site. As such, the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein unsafe. ---------0•0---- 2010-100 T200 FR 21 HWA GEOSCIENCES INC. October 3, 2016 HWA Project No. 20 I 0-100-21 Task 200 We appreciate the opportunity to provide geotechnical services on this project. Should you have any questions or comments, please do not hesitate to call. Sincerely, HWA GEOSCIENCES INC. BRADLEY W. C. THURBER Brad W. Thurber, L.G, L.E.G. Senior Engineering Geologist 2010-JOOT200 FR Sa H. Hong, P.E. Principal Geotechnical Engineer 22 HWA GEOSCIENCES INC. 6. REFERENCES AASHTO, 2014, LRFD Bridge Design Specifications, 7th Edition. Bartlett, S.F., Youd, T.L., 1992, Empirical analysis of horizontal ground displacement generated by liquefaction-induced lateral spread, Tech report NCEER-92-0021. Bohn Cecilia and Lambert Serge, 2013, Case Studies of Stone Columns Improvement in Seismic Areas, 3rd Conference. Maghrebine en Engenierie Geotechnique. Brandenberg et al, 2011, Recommended Design Practice for Pile Foundations in Laterally Spreading Ground, Pacific Earthquake Engineering Research Center. EERI and Washington Military Dept. -Emergency Management Division, 2005, Scenario.for a Magnitude 6. 7 Earthquake on the Seattle Fault. Ensoft, Inc (2002), Documentation of Computer Program LPILE. Federal Highway Administration (FI-I WA), 2013. Deep Mixing for Embankment and Foundation Support, Pub. No. FHWA-NRT-13-046, October 2013, McLean, VA. Federal Highway Administration (FHW A), 1983, Design and Construction of Stone Columns Volume I, Report No. FHW A/RD-83/026, December 1983, McLean, VA. Golder Associates Inc., 1995, Geotechnical Engineering Study -Monster Road Bridge Replacement, Renton, Washington. For INCA Engineers, Inc. dated January 23, 1995. Gower, H. D., J.C. Yount and R.S. Crosson, 1985, Seismotectonic Map of the Puget Sound Region, Washington. U. S. Geological Survey. Miscellaneous Investigations Series Map 1- 1613. Hall, J.B. and K.L. Othberg, 1974, Thickness of Unconsolidated Sediments, Puget Lowland, Washington, State of Washington, Department of Natural Resources, Division of Geology and Earth Resources. Idriss, I. M., and Boulanger, R. W., 2007, SPT and CPT based relationships for the residual shear strength of liquefied soils, Earthquake Geotechnical Engineering, Proc., 4th International Conf. on Earthq. Geotech. Engineering. Ishihara, K. and Yoshimine, M., 1992, Evaluation of Settlements in Sand Deposits following Liquefaction during Earthquakes, Soils and Foundations, Vol 15, No. I, pp 29-44. 23 McCrumb, D.R., et al., 1989, Tectonics, Seismicily, and Engineering Seismology in Washington, Engineering Geology in Washington, Vol. I, Washington Division of Geology and Earth Resources Bulletin 78, pp. 97-120. Rocscience Inc., 2013, Slide, Version 5.044, Computer Software. Seed, H.B., and Idriss, I. M. 1971, Simplified procedure for evaluating soil liquefaction potential, J. Soil Mech. Found. Div. Washington State Department of Transportation (WSDOT), 20 l l, Geotechnical Design Manual (GDM), M 46-03.06. Washington State Department of Transportation (WSDOT), 2014, Standard Specifications for Road, Bridge and Municipal Construction. / ), ( S 139th St S 144th St "' Ut 1 S 149t h St~ r. > iii ,! \. S l ~Olh St ~ 1" <.I') V, • J \3 ~ O- Ii> -S1 ~2ndSt r I • Great Amen can Casino Baker Blvd BASE MAP FROM GOOGLE MAPS -DATA MA P © 2015 IJW I HWA GEOSCIENCES INC. VICINITY MAP BLACK RIVER BRIDGE LAKE TO SOUND TRAIL RENTON , WASHINGTON SI S 1351h St • ,,. Black River R,p, ,-;Forest a nd Wetl Tukwi la Amrrak - . I . @'(~r~- FIGURE NO 1 P ROJECT NO 2010-100 T200 0 20 <IO 0 6 '6 6 'LJ Scale: 1"•20' BH-2 + BORING APPROXIMATE LOCATION AND DESIGNATION , , , ' , 11~00 ----+---------+--- ~ ' • lrlm1 I HWA GEOSCIENCES INC. BLACK RIVER BRIDGE LAKE TO SOUND TRAIL RENTON, WASHINGTON SITE AND EXPLORATION PLAN ' ' \ A• ' \ , A South • " North A' 0 L_ f!Qo1to,R<>O<l ---a Black.River Bridge (Lake to Sound Trail) ,o-,r-~~~~-===::::.._....,"-====~~~~~-:crh'======='====cc'c,'-,,====cc=========~r-~~~~~--f--n~~ FILL 2 FILL 10 ·I ALLUVIUM ? ·2 LEGEND BLOW COU~'T W~T£~ cfllfl Ar TIME OF ~·-GLAO.Al._ TILL " I ---+---1~~~~ GfOUX.IC " eonc~. Of BORJf!G 15+00 Th€ subsurface conclltklfi~ !>lvM1 <1re bil5ed on widely spaced borings and/or test pit5 and shook:! be considered approximate. Further, the cootact lines shown berween units are Interpretive in nat\Jre and "lilY vary l.iterally or 'lerticaHv over r0atively !ihort distance,; on site. 16+00 Black River 17+00 BLACK RIVER BRIDGE LAKE TO SOUND TRAIL RENTON, WASHINGTON ' __ , ' ---4llUVT(}N St< ?------t---? ALLUVIUM -'1!-to'"i =-.. I Al.t<N1("1 "'T ? ? +.GLACIAL TILL 20 :> :> ~30 BEDROCK CROSS SECTION A-A' so 60 70 om IHWAGEOSCIENCES (NC ...._ ___________________ __., 512[•\0•KOJEC~,.,,,,~,,..,,,. .. ro"""'""'-H"5>.,00Bu\C<.,.,.R.""""""'""·,,,.,.,.,,,...,,,,o""'""'"""'""''''-"""'''·""" I BLACK RIVER BRIDGE ffiltn I LAKE TO SOUND TRAIL 11uii1 HWAGEOSOENCES NC. RENTON,WASHINGTON Bl-I~ BORlNG APPROXIMATE LOCATION AND DESIGNATION • '""~'""''" "----:!:T--==.::.:...::.:.-------' ,.,_,_,,'""-'"-'"""---••••'"rn_,,.,,._,,,,,., __ .• ,_. - 2-0 0 EFK 4 PROPOSED GROUND ,-_l!l,1ITr__1,_-,-- IMPROVEMENT AREAS i"'O'io-100 10.4.16 T APPENDIX A FIELD INVESTIGATION APPENDIX A FIELD INVESTIGATION Two geotechnical borings were drilled for the proposed Black River Bridge, on November I 0, 2014 and January 6, 2015. These borings were designated BH-1 and BH-2, and were drilled at the top of the river banks in the general centerline of the proposed bridge alignment. The borings were drilled to maximum depths ranging from 61 to 86.5 feet below the existing ground surface. The exploration locations were located in the field by taping distances from known site features and plotted. The locations of the borings are indicated on Figures 2 and 3. The borings were drilled by Holocene Drilling, Inc. of Puyallup, Washington, under subcontract to HWA Geosciences Inc. The borings were advanced using a track-mounted, Diedrich D-50 drill rig equipped with hollow stem augers. Each of the explorations was completed under the full-time supervision and observation of an HWA geologist. Soil samples were collected at 2.5-to 5-foot intervals using Standard Penetration Test (SPT) methods in general accordance with ASTM D-1586. SPT sampling consisted of using a 2-inch outside diameter, split-spoon sampler driven with a I 40-pound drop hammer using a rope and cathead. During the test, a sample is obtained by driving the sampler 18 inches into the soil with the hammer free-falling 30 inches per blow. The number of blows required for each 6 inches of penetration is recorded. The Standard Penetration Resistance ("N-value") of the soil is calculated as the number of blows required for the final I 2 inches of penetration. This resistance, or N-value, provides an indication of the relative density of granular soils and the relative consistency of cohesive soils. HWA personnel recorded pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and ground water occurrence. Soils were classified in general accordance with the classification system described in Figure A-1, which also provides a key to the exploration log symbols. Representative soil samples were taken to our laboratory for further examination. The summary logs of boreholes are presented on Figures A-2 and A-3. The stratigraphic contacts shown on the individual logs represent the approximate boundaries between soil types; actual transitions may be more gradual. Moreover, the soil and ground water conditions depicted are only for the specific locations and dates reported and, therefore, are not necessarily representative of other locations and times. 2.010-100T200FR A-I HWA GEOSC!ENCES INC. RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE COHESIONLESS SOILS COHESIVE SOILS Approximate Approximate Density N (blows/ft) Relative Density(%) Consistency N (blows/ft) Undrained Shear Strength (psf) Very Loose 0 lo 4 0 15 Very Soft 0 lo 2 <250 Loose 4 to 10 15 35 Soft 2 lo 4 250 500 Medium Dense 10 to 30 35 65 Medium Stiff 4 to 8 500 1000 Dense 30 lo 50 65 85 Stiff 8 lo 15 1000 2000 Very Dense over 50 85 100 Very Shff 15 to 30 2000 4000 "'"' over 30 >4000 uses SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS ·-GW Gravel and Clean Gravel ·•· Well-graded GRAVEL Coarse Grained Gravelly Soils (11!\le or r10 fines) -~Cs GP Poorly-gr<1ded GRAVEL Soils More than 50% of Coarse Gravel w,th 0 GM Silty GRAVEL FracUon Retained Fines (appreciable on No. 4 Sieve amount of fines) ~ GC Clayey GRAVEL Sand and Clean Sand ... SW Well-graded SAND More than Sandy Soils (l1ttla or no fmes) Ii SP Poorly-graded SAND 50% Retained 50% or More ll on No. Sand with SM S111ySAND of Coarse 200 Sieve Fines (appreciable ~. So, Fraction Passing amount of fines) SC Clayey SAND No. 4 S1e~e ML SILT Fine Sill Grained aod Liquid Limit CL Less than 50% Lean CLAY Soils Clay -~-OL Organic SILT/Organic CLAY - C MH Elastic SILT Silt 50% or More Liquid Limit Passing aod CH Fat CLAY Clay 50% or More No. 200 Sieve S12e OH Organic Sil T/Organic CLAY ,,,, Highly Organic Soils PT PEAT J ,If %F AL TEST SYMBOLS Percent Fines Atterberg Limits: PL = Plastic Limit LL = Liquid Limit CBR Cal1fom1a Bearing Ratio CN Consolidation DD Dry Density (pcf) OS Direct Shear GS Grain Size Distribution K Permeability MD Moisture/Density Relationship (Proctor) MR PIO pp Resilient Modulus Photoionizat1on Device Reading Pocket Penetrometer Approx. Compressive Strength {!sf) SG Specific Gravity TC Triax1al Compression TV Torvane Approx. Shear Strength (tsf) UC Unconfined Compression ~ I B 0 ~ LI 0 SAMPLE TYPE SYMBOLS 2.0" OD Split Spoon (SPT) (140 lb. hammer with 30 1n. drop) Shelby Tube 3-1/4" OD Split Spoon with Brass Rings Small Bag Sample Large Bag (Bulk) Sample Core Run Non-standard Penetration Test (3.0" OD split spoon) GROUNDWATER SYMBOLS Groundwater Level {measured at time of drilling) Groundwater Level (measured in well or open hole after water level stabilized) COMPONENT DEFINITIONS COMPONENT PROPORTIONS COMPONENT SIZE RANGE PROPORTION RANGE DESCRIPTIVE TERMS Boulders Larger than 12 in <5% Clean Cobbles 3mto12in Gravel 3 in to No 4 (4.5mm) Coarse gravel Jin to 3/4 in 5-12% Slightly (Clayey, Silly, Sandy) Fine gravel 314 1n to No 4 (4.5mm) Sand No. 4 (4.5 mm) to No. 200 (0.074 mm) 12-30% Clayey, Silty, Sandy, Gravelly Coarse sand No. 4 (4.5 mm) to No. 10 (2.0 mm) Medium sand No. 10 (2.0 mm) to No. 40 (0.42 mm) 30-50% Very (Clayey, Silty, Sandy. Gravelly) Fine sand No. 40 (0.42 mm) to No. 200 (0.074 mm) Sill and Clay Smallerthan No. 200 (0.074mm) Components are arranged in order of increasing quantities NOTES: Soil classifications presented on exploration logs are based on visual and laboratory observation. Soil descriptions are presented in the following general order- Densitylconsistency, color, modifier (if any) GROUP NAME, additions to group name (if any), moisture content. Proportion, gradation, and angularity of constituents, additional comments. (GEOLOGIC INTERPRETATION) Please refer to the discussion in the report text as well as the exploration logs for a more complete description of subsurface conditions. -HWAGEoSclENCES INC Lake to Sound Trail Black River Bridge Renton, Washington MOISTURE CONTENT DRY MOIST WET Absence of moisture, dusty, dry to the touch. Damp but no visible waler. V1s1ble free water, usually soil is below waler table. LEGEND OF TERMS AND SYMBOLS USED ON EXPLORATION LOGS PROJECTNO.c 2010-100-200 FIGURE: LEGEND 2010-100-200.GPJ 2120115 A-1 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: Diedrich D-50 track rig with HSA SAMPLING METHOD: SPT Autohammer SURFACE ELEVATION: 26.50 :I: feet "' "' :s <.) ~ ~ i5 :c 0 "' tz-"' "' "' <.) w fil >-"' ""-"' :, DESCRIPTION 0 - ·:::t::·1:i: SM Medium dense, gray, silty to slightly silty, fine SAND, moist. -Blocky tei,:ture, light broNn at surface, trace organics and -burnt VvOOd bits. -'·' (FILL) -ML Medium dense, dark grayish brown, sandy SILT, moist. -5 -ML Very loose to medium dense, gray, fine sandy SILT, moist to wet. Trace organic bits and layers, some laminar bedding. -(ALLUVIUM) 10 - Blow counts are weight of hammer only. Sample is wet at tip of sample. Ground water seepage was 15 -observed at 13.5 feet below ground surface. Abundant organics in sample. - 20 - laminar layers or organics. - --------------------SM 25 - Lots of heave encountered, 4-5 feet cleaned out of auger. -Loose, grayish brown, silty, fine SAND, wet. : -:_:-::. .: -. '/:· 30 No recovery of sample . . -:_:--· . . -. ,._:- -SM Medium dense, gray, silty, gravelly, fine to coarse SAND, 'Net. -·:· ::: ... Wood bits and organics observed. :_:· . (ALLWIUM) 35 . : .. . -... -... · . .... :_. 40 - a: w w <.) w m ~ U) "' 0. "' >-• >->-:, "'~ "' >-z -0 w w w U) .!= >- ~ ~ ~ !,e a: 0. 0. ,d w "' "' :c " " ~e >- "' "' 0 0s-1 6-9-10 0s-2 9-9-8 GS 0 S-3 4-S.5 GS 0$-4 2-2-3 0s-5 0-0-0 GS 0S-6 1-0-1 0S-7 0-0-0 GS 0s-a 1-1-1 0S-9 1-2-2 GS ~S-10 3-6-10 ~S-11 6-10-10 For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the oeotechnical report. NOTE: ""rhis log of subsurface conditions applies only at the specified bcation and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. -HWAGEoSCIENWINC Lake to Sound Trail Black River Bridge Renton, Washington LOCA _ : See Figure 2 DATE STARTED: 11/10/2014 DATE COMPLETED: 11/10/2014 LOGGED BY: D. Coltrane a: w ~ :,: 0 z :, 0 a: CJ 0 ~ 0 Standard Penetration Test (140 lb. v.tJight, 30'' drop} A Blows per foot 10 20 30 .. .. , ... ... • .. ··• ... 20 ., • •• ••••• • 60 Water Content{%) 40 80 Plastic Limit I e I Liquid Limit Natural Water Content BORING: BH-1 PAGE: 1 of 2 PROJECTNO.: 2010-100-200 FIGLJRE" BORING 2010-100-200.GPJ 9112116 :c Ii:"' wj 50 0- 0 5 10 15 20 25 30 35 40 100 A-2 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: Diedrich D-50 track rig with HSA SAMPLING METHOD: SPT Autohammer SURFACE ELEVATION: 26.50 :I: feet J: >--CL -~! 40 45 50 55 60 65 70 75 80 "' "' '.I l) ~ ~ i5 0 "' "' "' :, l) >-"' "' ::, SM DESCRIPTION Medium dense to very dense, ijght brown, gravelly, silty, fine to coarse SAND, v.et. Angular gravel and sands, blocky texture. (GLACIAL TILL) Bluish gray, moderately weak, highly v.eathered, fractured, basalt. Speckled coloring. {WEATHERED BEDROCK) """"----1, Bluish gray, moderately strong, moderately weathered, fractured, BASALT. Speckled coloring. (TUKWILA FORMATION) Boring was terminated at 61 feet below suriace in bedrock. Ground water seepage was observed at 13.5 feet below ground surface. O'. w w l) "' 2-"' w " . CL :, >-• >->-::, "'~ "' >-2 -0 w oo .E >-w w Wm ~ ~ "' -. O'. CL CL w :, :, :i. ~ J: " " w" >- "' "' CL -0 ~S-12 9-7-16 GS ~S-13 12-27-44 ~S-14 26-13-15 ~ S-15 12-10-25 [i<J S-16 50-50/2'' For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the aeotechnical report. NOTE: lhis log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. -HWAGEoSCIENCES INC Lake to Sound Trail Black River Bridge Renton, Washington LOCATION: See Figure 2 DATE STARTED: 11/10/2014 DATE COMPLETED: 11110/2014 LOGGED BY: D. Coltrane O'. w >-~ 0 2 ::, 0 O'. "' 0 0 10 • 20 Standard Penetration Test (140 lb. v.eight, 30" drop) A Blows per foot 20 30 40 ..... •· 40 60 80 Water Content(%) Plastic Limit I e I Liquid Limit Natural Water Content BORING: BH-1 PAGE: 2 of 2 PROJECTNO.: 2010-100-200 FIGURE: BORING 2010-100-200.GPJ 9112/16 50 45 50 55 60 65 70 75 80 100 A-2 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: Diedrich D-50 track rig with HSA SAMPLING METHOD: SPT Autohammer SURFACE ELEVATION: 29.00 t feet "' 0: w "' w u '.'i w "' Z-"' " <( • u 0.. f-• f-__, ~ ::, "'~ "' z -u w __, 6 w w "'.!: f- r 0 "' __, __, ~ i: "' f--"' "' 0.. 0.. •• w o..-" u " " Z O r ~:! :,. "' <( <( ~e f- "' ::, DESCRIPTION "' "' 0 0 SP Grass at surface. SM ~ S-1 20-18-19 Dense, light brov.in, slightly silty, slightly gravelly, SANO, moist. Broken gravels and concrete. 5 (FILL) ~ S-2 9--12-15 ML ~ S-3 SM Medium dense, gray, slightly gravelly, very sandy SILT, moist. 4-5-7 GS Wood bits observed. 10 ~S-4 5-10-10 ~ S-5 3-6-6 15 ~ S-6 5-7-8 GS SM loose, gray and bro'Ml, interbedded fine to medium SAND ~ S-7 2-2-2 with SILT layers, moist to wet. 20 Ground \\later seepage observed at 19.0 feet during drilling. SP Loose, gray, slightly silty SAND, wet. Initial 6-inch blow count ~ S-8 30-1-2 is from chunk of rubber in sampler. 25 GP Loose, gray, sandy, fine GRAVEL, wet. (ALLUVIUM) ~ S-9 1-2-4 30 ~S-10 3-3-3 35 ~S-11 4-3-3 40 For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the aeotechnical report. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. -HWAGEoSCIENCFS INC Lake to Sound Trail Black River Bridge Renton, Washington LOCA See Figure 2 DATE STARTED: 1/6/2015 DATE COMPLETED: 116/2015 LOGGED BY: D. Coltrane 0: w i " z ::, 0 "' co 0 ~ 0 Standard Penetration Test (140 lb. weight, 30" drop) A Blows per foot 10 20 30 40 •• •• • •• •• • • •• • • • • ·••· ...... • • 20 40 60 Water Content(%) Plastic Limit I e I Liquid Limit Natural Water Content BORING: BH-2 PAGE: 1 of 3 PROJECTNO.• 2010-100-200 FIGURE· BORING 2010-100-200.GPJ 9112116 r tc;:- wfil 50 "~ 0 5 10 15 20 25 30 35 40 A-3 DRILLING COMPANY: rlolocene Drilling DRILLING METHOD: Diedrich 0-50 track rig with HSA SAMPLING METHOD: SPT Autohammer SURFACE ELEVATION: 29.00 :t feet _, I 0 Ii:= "' " ~! >-"' 40 45 50 55 60 "' "' '.'i u _, i5 "' "' u "' ::, GP SP DESCRIPTION Dense, gray, slightly silty, sandy GRAVEL, wet. Broken gravels in sampler. Medium dense, black, fine to medium SAND, wet. Bits of w:xx:l noted in samples. Medium dense, dark gray, slightly silty, fine to medium SAND, wet. Shells observed. O'. w w u Z-w "' "'. Q. " f-• ~ ::, "'~ z -u w w Cl).!: w~ _, _, O'. " Q. Q. •• " " z 0 ;\ "' w- "' a. e ·~s-12 6-16-19 .. ~S-13 4-8-11 ~S-14 2-11-10 ~S-15 7-10-11 ~S-16 6-10-13 "' f- "' w f- O'. w I f- 0 GS GS LOCATION: See Figure 2 DATE STARTED: 1/6/2015 DATE COMPLETED: 1/6/2015 LOGGED BY: D. Coltrane O'. Standard Penetration Test w a' (140 lb. weight. 30" drop) " A Blows per foot 0 z ::, 0 O'. CJ 0 10 20 30 . .. ••• I f--a.-~! 40 50 40 45 50 55 60 • • 70 75 BO GM Drilling becomes gravelly. Poor recovery; broken gravel. Dense, gray, sandy, silty GR<\VEL, wet. Broken gravels in sampler. (GLACIAL TILL) ~S-17 6-20-19 ~S-18 9-11-20 GS For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the oeotechnical report. NOTE: ]his log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. -HWAGEoSCIENCES INC Lake to Sound Trail Black River Bridge Renton, Washington 0 20 40 60 80 Water Content(%) Plastic Limit I e I liquid Limit Natural Water Content BORING: BH-2 PAGE: 2 of 3 PROJECT NO• 2010-100-200 FIQLJRE: BORING 2010-100-200.GPJ 9112116 70 75 80 100 A-3 DRILLING COMPANY: Holocene Drilling DRILLING METHOD: Diedrich D-50 track rig with HSA SAMPLING METHOD: SPT Autohammer SURFACE ELEVATION: 29.00 :i: feet "' "' '.S Ll ~ ~ 5 J: 0 "' li::c <D <I) " Ll ~! >-<I) "' :, DESCRIPTION 80 Becomes medium dense, broken gravel in sampler. 85 "' w w Ll <D Z-w <( • 0. " t-• >-:, <I)~ t-z -0 w w U) .:: ~ ~ Ww 0. 0. "' ., " " •• Z a " " ~e "' "' 03-19 12-13-17 C:S.!Ll_-1., Very dense, gray, sandy, gravelly SILT, wet. rv1ost likely driven ZI S-20 50/4" 90 95 100 105 110 115 120 on boulder. Boring terminated at 86.5 feet below ground surface due to refusal. Ground water seepage was observed at 19 feet below-ground surface during the exploration. <I) t- <I) w t- "' w :c t- 0 GS For a proper understanding of the nature of subsurface ccnditions, this exploration log should be read in conjunction with the text of the qeotechnical report. NOTE: lhis log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. -HWA.GEoSCIENCEs INC Lake to Sound Trail Black River Bridge Renton, Washington LOCA : See Figure 2 DATE STARTED: 1/6/2015 DATE COMPLETED: 1/6/2015 LOGGED BY: D. Coltrane "' Standard Penetration Test w i Cl z :, 0 "' " 0 0 {140 lb. weight, 30" drop) .&. Blows per foot 20 30 40 20 40 60 80 Water Content(%) Plastic Limit I e I Uquid Limit Natural Water Content BORING: BH-2 PAGE: 3 of 3 PROJECTNO., 2010-100-200 FIGURE: BORING 2010-100-200.GPJ 9112116 J: li::c ~! 50 80 85 90 95 100 105 110 115 120 100 A-3 APPENDIXB LABORATORY INVESTIGATION APPENDIXB LABORATORY TESTING Laboratory tests were performed on selected samples obtained from the borings to characterize relevant engineering and index properties of the site soils. Because of the predominantly coarse- grained nature of the encountered soils, the collected and tested samples should not be considered representative of the existing soils. For the same reason, only a limited number of laboratory tests could be performed on the obtained soil samples. HWA personnel performed laboratory tests in general accordance with appropriate ASTM test methods. We tested selected soil samples to determine moisture content and grain-size distribution. The test procedures and results are briefly discussed below. Moisture Content Laboratory tests were conducted to determine the moisture content of selected soil samples, in general accordance with ASTM D-2216. Test results are indicated at the sampled intervals on the appropriate boring logs in Appendix A. Grain Size Analysis The grain size distributions of selected soil samples were determined in general accordance with ASTM D 422. Grain size distribution curves for the tested samples are presented on Figures B-1 through B-4. 2010-1001'200 FR B-1 HWA GEOSC!ENCES ]NC. I GRAVEL I SAND I Coarse Fine I Coarse Medium Fine U.S. STANDARD SIEVE SIZES 314" 3" 1-1/2" I 5/8" 318" 100 ' : I I I I 90 ' I ' I I I BO f-I I I ! I I g I 70 w I I ;;: ' ! ' I >-60 "' I O'. I w 50 II z u: ,I f-40 :1 z II I 11 w 0 I O'. 30 . w I Q_ • I 20 I I 10 . I II I I 0 50 10 SYMBOL SAMPLE DEPTH (ft) • BH-1 S-2 5.0 -6.5 • BH-1 S-3 7.5-9.0 • BH-1 S-5 12.5-14.0 mm, HWAGEOSCIENCES INC HWAGRSZ 2010-100-200GPJ 2120115 #4 #10 #20 #40 •'!" #100 #200 -,,.-~ -] • I I I ' " -"1 \ I I 'I ' '\ I .\ I I 'I • I I ' :1 ; : I II I I " I ' I -, ,, I • I I : : Ii I II I I I I " 1 05 0.1 0.05 GRAIN SIZE IN MILLIMETERS CLASSIFICATION OF SOIL-ASTM 02487 Group Symbol and Name (ML) Dark grayish brown, Sandy SILT (ML) Dark grayish brown, SILT with sand (ML) Gray, SILT with sand Lake to Sound Trail Black River Bridge Renton, Washington SILT CLAY 11 ' ' i ! ' ' ' ! ' I I I I I ' I I ' ' i ! 0.01 0.005 0.001 0.0005 %MC[ LL PL Pl "Grovel Sand Fines ,, ,, ,, 16 i 1.7 40.4 57.9 i :1 0.7 21.7 77.6 15.0 85.0 PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D422 PROJEC7NO 2010-100-200 FIGURE B-1 I GRAVEL I SAND I Coarse I Fine I Coarse I Medium I Fine l U.S. STANDARD SIEVE SIZES 3/4" 3' 1-1/2" I 5;8" 3/8" #4 #10 #20 #40 #60 #100 #200 ~ 100 Ii ~ ~ . I I I '11--i "' I I I I I 90 I' 11 I ~ jl I ~ I ,. I I I 1--I I I 80 " 1, f--I I I 11 I I (!) " 70 w I I 11 s: 1: 1! ! I >-60 I I I co 0:: 1' w 50 I z ,: U: " f--40 11 II I z w ,: () 0:: 30 I' I' ' w a. 20 " " ' " " . 10 !I ,: ,: . 0 50 10 ~YMBOI SAMPLE DEPTH {ft) • BH-1 S-7 17.5 -19.0 • BH-1 S-9 25.0 -26.5 .. BH-1 S-12 40.0-41.5 um HWAGEoSclENcEs INC isWAGRSl 2010-100-200GPJ 2120115 " ~ I I I I I ! \ ! " I IC,-_ r+ ~ 1; I II ' I [\" I I \ ~ I I ' I I ~ I I ,, I I I I I I ; ; I I I I 1! ' ' ' 1 0.5 0.1 0.05 GRAIN SIZE IN MILLIMETERS CLASSIFICATION OF SOIL-ASTM 02487 Group Symbol and Name (ML) Gray, SILT 'Mth sand and organics (SM) Grayish brown, Silty SAND (SM) Yellowish brown, Silty SAND with gravel Lake to Sound Trail Black River Bridge Renton, Washington SILT CLAY 0.01 0.005 0.001 0.0005 %MC LL PL Pl Gr:_vel s~,nd Fi~es 56 20.4 79.6 38 71.8 28.2 25 15.3 39.4 45.3 PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D422 PROJECT NO 201 Q-1 QQ-2QQ FIGURE: 8-2 GRAVEL SAND Coarse Fine Coarse Medium Fine U.S. STANDARD SIEVE SIZES 314' 3" 100 1 1/2" 5/8" 3/8" >-I Cl w ;;: 90 BO 70 >-60 "' 0:: W 50 z u: f-40 z w ~ 30 w c.. 20 10 a ', I I I I I I I ! ,! 'I 1, I ,, 50 SYMBOL SAMPLE • BH-2 • BH-2 .. BH-2 mm, I I ' Ii i I II I I " I I ,: I I: I I Ii ! S-3 S-6 S-13 HWAGEoSCIENCES INC HWAGRSZ 2010-100-200GPJ 2120115 I I I , I i ! I I I I DEPTH (fl} 7.5 -90 15.0-16.5 45.0 -46.5 #4 #10 #20 #40 #60 #100 #200 I i i ', ~ I I I I ~ ~ " ~, I I '" ! I I ' Ki I I ! I j I I I~ I I I ! I Ii ! 1 I I I i I I I I I I I \ I I I I i I I ,, II ' i i i I I I I I " i i I " 'i I I I I " !I i\ ' I I i " " i ! '-I I I I!, !I i ! I~. I I ' 1 0.5 0.1 0.05 GRAIN SIZE IN MILLIMETERS CLASSIFICATION OF SOIL-ASTM 02487 Group Symbol and Name (ML) Dark grayish brown, sandy SILT (ML) Dark grayish brown, sandy SILT (SP) Black, Poorly graded SAND Lake to Sound Trail Black River Bridge Renton, Washington SILT CLAY ! I ! ' i ' ! I I i ' i ! I 0.01 0.005 0.001 0.0005 %MC LL PL Pl Gravel I Sand Fines "' ' "' "' 19 18 29 1.2 46.8 52.0 3.2 44.2 52.7 5.7 89.9 4.3 PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM D422 PROJECTNO.: 2Q1Q-10Q-2QQ FIGURE· B-3 GRAVEL SAND Coarse Fine Coarse Medium Fine U.S. STANDARD SIEVE SIZES 3' 100 90 60 314" 1-1/2" I 516" 318" \ ~I I \ti I I #4 I I r Ii #10 #20 #40 #60 #100 #200 . . ~ I I I I I I I I I I -I i i I ! ! I f- I ~ 70 Ii ~ ~~ 1: ; I \ I I ~ I I ! ! I w ;;: >-Ol c:: w z u: I;: w ~ w a. SYMBOL • • • 6-0 ,, 50 40 " 3-0 I' 20 10 Ii 0 so SAMPLE BH-2 BH-2 BH-2 um 1: ' I! ' 1: ' 1: ; Ii S-16 5-18 S-20 HWAGEOSCIENCFS INC H\l\'AGRSZ 201(>.100·200.G~J 2120115 10 DEPTH (ft) 60.0 -61.5 75.0 -76.5 86.0 -86.5 I I I I I 1! I I ~ ' I l : ~ I I I I I I I I \ I I I I I 1: ' ' ' I I I I I 1, ' i ' I I i I I j\ I 1! i ! N I I I ,! I I I . ' 5 1 0.5 0.1 0.05 GRAIN SIZE IN MILLIMETERS CLASSIFICATION OF SOIL-ASTM 02487 Group Symbol and Name (SP-SM) Dark gray, Poorly graded SAND with silt (GM) Gray, Silty GRAVEL with sand (Ml) Gray, Sil T with sand Lake to Sound Trail Black River Bridge Renton, Washington SILT CLAY I I 0.01 0.005 0.001 0.0005 %MC LL PL Pl Gravel Sand Fines " '" •; . 23 0.9 92.0 7.1 21 27.7 22.7 49.6 21 12.3 23.5 64.2 PARTICLE-SIZE ANALYSIS OF SOILS METHOD ASTM 0422 PROJECT NO.: 2Q1Q-1QQ-2QQ FIGURE B-4 APPENDIXC SLOPE STABILITY ANALYSES, COMPUTER CALCULATION RESULTS :5atety r•c"Cor 0 .000 ~ 0 .500 1.000 1,500 ~ 2.000 2.SOO :!.000 3.SOO ~ '4,000 4.SOO s.ooo ~ 5.SOO (i,0001- ~ ~ ~ ~ ~ .... Project Number . 20 10-100-21 Task·200 P,oject Name . 8'ack Rtver Bndge lake lo Sound Tra il Renlon . Washington Analysis Methods use-d Bishop simplified Spence, Janbu simplrfie<I South Side· Static Analysis •100 Material: Fill Slrenglh Type: Mohr.Coulomb Uno Weight 1 JO lb/Ill Fr,c11on Angl e 36 degrees T •120 Material · Loose Sand Strenglh Type : Mohr.Coulomb Un< Weight 110 lb/113 Fnc11on Angle 28 degrees Material: Medium Dense .4Jh.Mum Strength Type Mohr-Coolomb Unit Wetgln: 124 ll>'lll Friction Angle: 35 degrees Matenal: Glacial TiH Strength Type. Mohr-Cou!omb Und Weigh t· 134 lb/113 Fricti on Angle: 36 degree, .,.., ., ... ~11D STATIC STAB ILITY: SOUTH ABUTMENT u~ I HWA GEOSCIENCES INC BLACK RIVER BRIDGE LAKE TO SO UND TRAIL RENTON, WA e,oo PROJECT 00 2010-100-2 1 Sa.!ety F<?.c tor 0.000 ! 0 .500 1 .0 0 0 1 .5(10 ~ 2 .000 2.500 3 .000 ! 3.500 4 .000 4 .5 00 5.000 ~ 5.500 ,.ooo + ~ ~ ~ ~ § .... .... Pro1ec1 Number· 20 10-100-21 Tas k·200 PJ oiect Name. Black RN'E'1 Budge lake to Sound T1a1I Rerioo . W3shtnglon Material: F1U S11eng1h Type Mohr-Coulomb Und W eight 130 1Wft3 Fu ct ion Angle. 36 deg1ees ·,.....-.!!.. _______ _ Analysis Methods used· Bishop s1mptrfied Spencer Janbu s1mplrfied Malena! l oose Sand Strength Type· Mohr-Coulomb Unit We;gt,1 110 11>i11 3 Fnctrnn Angle 28 degrees Maten.al· Medium Dense Allwum Strength Type . Moh1.Coulomb Unn Weight 124 lblft3 F ricttOn Ang.e: 35 degr ees Mateual. Qac1al Tin St1ength Type Moh,.Coulomb Unit Wei ght. 13d lt.'ft3 Fnct1on Angle : 36 degrees 1"------------------1·~·1----------------., e-100 et 0!00 <220 e,240, e2ao e,oo SEIS MI C STABILITY: S OUTH ABUTMENT (DE SIGN EVENT) u~, I HWAGEOSCIENCEs lN C. B LACK R IVE R BRIDGE LAKE T O SOUND T RAIL RENTON, WA PROJECT NO 2010-100-2 1 ~ Sal~t v !'actor 0.000 0 .500 1 .(100 ! 1.soo 2 .(100 2.500 ~ 3.000 3 .500 4..000 4 .500 § 5.000 5 .500 6.000+ ~ ~ ~ ~ § .... P1oiec1 Number. 2010-100-21 Task:200 Pro.,ec1 Name . Black Rr.-er Sndge lak.e to S ound Trail R&nton. Washington South SKl e: Post Liquefaction Anatysis M.rteriaJ F~I Strength Type . Mohr-Coul omb Uno We~ht. 130 lblft3 Fuctton Angle : 36 di gree s . , .. 0'20 M atenal· loose Sand Strengt h Type : Mohr -Coolomb Unil Weight 11 0 lb/113 FnC11on Angle· 5 degrees ~fatena1· Medium Dense AIILMum Stre ngth Type. Moh r.Coulomb Uni! Weighl 124 11>'!13 Frict ion Angle: 35 degees Matenal: Glacial Til St,engt h Type· Mol-.-Coulon-b Unit Weight: 134 lb/113 Frid ion Angle. 36 degrees ..... e110 o~, I HWA GEosc,ENCES INC. 0200 <280 POST LIQUEFACTIO N STABILITY: SOUTH A BUTMENT (DES IGN EV ENT) BLACK RIVER BR IDGE LAKE TO SOUND TRAIL RENTON .WA PROJ ECT NO. 2010-100-21 Safety !'ac tc-:: ' 0.000 o.soo l .lJOO 1 .500 ~ ,.ooo ;.500 ).000 ~ 3.500 4 .0(10 4.50(' ~ 5 ,00{'1 s.soo 6,0(10 ,j, ~ ~ ~ ~ ~ e 120 Proiect Number. 2010-100-21 Tssk.200 Project Narne Black River Bridge Lake to Sound Trai l Rent on , Washington North Side: S1auc. Anatys1s Material. Medium Dense AJh.MUm Strength Type· Mohr-Coulomb Un< We,ghl 124 lblft3 Cohesion· 1 psf Fnclion An9'e 34 degrees .... 6110 Material Medium Dense Glac ial Till Suength Type Mohr-Coulomb Unrt We ight. 130 11>1ft 3 Cohesion· 1 psf Fnctioo Angle. 36 degrees ::r~ I HWAGEOSCIENCES INC Analysis Methods used Bishop s,mphfied Janbu simplified Spencer Mateual FiU S1re1191h Type-M ohr-Coolomb Un,t we,gt,1 130 lb/113 C hes1on: O psf F 1ction Angle 36 degees Material. Loose Sand Strengih Type-Mohr-Coulomb Umt We,ghl tlO 11>'!1 3 Cohesion· 1 psf F nctionAngle . 28 degrees M.tenal Bed Rock S1rength Type · Mohr-C oulomb Unrt Weight 145 lblft3 Cohesion 1 psf Fuc:t1on Angle 45 deg,ees STATIC STABILITY: NORTH ABUTMENT BL AC K RIVER BRIDGE LAKE TO SO UN D TRAIL RENTON , WA PROJECT NO 20 10-100-21 Safety f actor ! 0.000 0,500 1.000 ! 1.SOO 2.000 2 .500 3.000 ~ 3.500 ,.ooc 4 ,500 ~ 5,000 5.500 6 .(100+ ~ ~ ~ ~ ~ 0120 0140 Project Number. 20 10-100 -21 Ta sk.200 Projecl Name Black Aiyer Bridge l ake to Sound Trail Aen1on. Washington Nor1h Side . Ps,udo ~ Static Analysis Malerial. Medium Denn Alluvium Strength T)'J)e. Mohr-Coulomb Umt We,ght 124 lblft3 Cohesion· 1 psf Friction Angle : 34 degrees .... ~110 D&i1 I HWA GEOSCIENCES IN C. Material: Medium Dense Glacial Till Strength Type · Mohr-Coulomb Unrt Weight: 134 ID!ft 3 Cohesion: 1 psf frict ion Anfje . 36 degrees 0200 Matenal: Fill Strength Type Mot.-Coulomb Uno Weight: 130 tb/113 Cohes,on· 0 psi Friction Angle 36 deg,ees ',,..~------..,::, __ ...;• Mattrial· loose Sand Strength Type. Mohr-Coulomb unn Weight · 11 0 tb/113 CohesW>n· I psr Friction AnfJ.e : 28 degree s Matenal: Bed Rock St,ength Type : Moh r-Coulomb Un,t Weight. 145 lbtl3 Cohesion· 1 psf Fnt11on Angle · 4 S degrees L.'"'"' F'" . ..., SEISMIC STABILITY: NORTH ABUTMENT (DES IGN EVENT) BLACK RIVER BR IDGE LAKE T O SOUND TRAIL RENTON, WA PROJECT NO 2010-100-21 ~ Sduy Factor 0 .000 0.500 1.000 ' 1.SOO 2.000 2.500 3 .000 ~ 3. soo 4 ,000 4 • .500 ~ s.ooo 5.500 ,.oOO • ~ i ~ ! e120 .... Project Number 201 0-100 -21 Ta sk 200 Pro1ect Name Black River Bndge La~e to Sound Trail Renton. W ashing1on North Side. Post Liquefaction Analysis Matenal· Med10m Den se All~um Strength Type Mohr -Coulomb Unrt Weight 124 lb/!1.3 Cohe sion 1 psf Fricuon Angle 34 de91ees Material: Medium Dense Glacial Ttll Strength Type · Mohr-Coulomb UM Weight · 134 lb/!13 Cohesion. 1 psf Friction Angle: 36 degrees e,eo 0180 ., .. :r~, I HWAGEOSCIENCES INC Mate nal Fri! Strength Type . Mohr-Coulomb Unn Weight 130 lb/!1.3 Cohesion· 0 psf Friction Angle 36 degree• Material Loose Sand Strength Type. Mohr-Coulomb UM Weight 110 lblft3 Cohes,on 1 psf Friction Angle 5 deg,ees Matenal Bed Rock Strength Type : Mohr-Coulomb Unn Weight 145 tbl!l.3 Cohesion · 1 psf Friction Angle 45 degrees ... .. P OST LI QUEFACTION STABILITY: NORTH A B UTM ENT (DESIGN EVENT) BLAC K RIV ER BRI DGE LAKE T O SOUND T RAIL RENTON , W A •• PROJECT NO 201 0-100 -2 1 Safety F•etcr 0 .000 ¥ 0 .500 1.000 l.SOO 2,000 ~ 2,500 3 .000 3.SOO ! •• ooo 4..SOO S.000 § s.soo 6 .000+ ~ ~ ~ ~ ~ .... 0020 Fill Strengch Type . Mohr-Coulomb Un,1 Weight 130 lb/113 CohOSl()l1 " 0 psi Frit110n Angle · 36 deg:tes Water Surface Water Table Loos, Sand Slrength Typo . Mohr-Coulomb Unn Weight . 110 lblllJ Cohesion: 1 psf Fnchon Artg.e · 28 degrees Water Surface Wate r Tabte Medium Dense .A.Jh.Mu m Strength Typo . Mohr-Coulomb Unl Weight. 124 lblft3 Cohesion 1 psi Fnclion Angle 35 degrees Water Surface: Water Ta~e .... 0000 n~, I HWA GEOSCIINCEs INC. Projecl Numbe~ 2010-100-21 Task·200 Project Name . Black River Budge Lake lo Sound Trail Ren1on , Washington South S,de : Stat«: Anelysis After Ground lmprovemenls (Stone Columns) GJacial Till Slrength Type . Moh r-Coulomb Unn Weight . 134 lb'lJ Cohesion· 1 psf Fnction Angle · 36 degrees Wmer Surlace: Water Table lmproved Matenal Strength Type: Mohr-Coulomb Unit Weigh!. 115 lb/113 Coliesion . 1 psi Friction Angl e 32 degrees Wate r Surface· Water Table eoso 15100 0120 .... !Mediu m DenseAlllMum! .... 15110 .. .. STATIC STABI LITY AFTER GROUND IMPROVEMENTS : STONE C OLUMNS -SOU T H ABUTMENT BLACK R IVER BRIDGE LAKE TO SOUND TRAIL .... PROJECT NO 2010-100-21 .... Proj<cl Number 2010-100-2 1 Task ·200 Pio~cl Name· Blatk R.,,., Bridge L.ake 10 Sound Tra,I Renton . Wa shing1on Nonh Stde S1a11c A.nalysis Afte r Ground lmprcwemenl s {Stone Columns) Fill Strength Type Mohl-Coulomb Unrt W e,ghl 130 lb/113 Cohesion o psf Friction Angle 36 degrees Water Surface Water Table Loose Sand Strenglh Type. Mohl-Coulomb Uno We,ght 110 lb/!13 Cohes,on 1 psf Ftict1onAngle. 28 d&g,ees Wate r Surface Water Table Medium Dense AlllMum Strengl h Type Mohr-Coulomb Unn Weight 124 lb/113 Cohes,oo. 1 psf F ri<;hon Angle 34 degrees Water Surfsce . Water Table •• .... Glaci al HI Strength Type Mohr-Coulomb Unrt Wetght 134 lblft3 Cohesion · I p<f FncttonAngle · 36 degrees Water Surface · Water Ta bl e Bed Roc k Strength Type· Mohl-Coulomb Unn Weight· 14 5 lblft3 Cohes oo 1 psf Fnct1on Angle 45 degrees Wal er Surface · Water Table knproved Malena! Strength Type · Mohr-Coulomb Unrt Weight· 115 lblft3 Coheston 1 psf Fnction Angle 32 degrees W ater Surface Wal er Tabl e .... Ir~ I HWA GEOSCIENCES lNC. !Dense Glacral Tin! Analysis ~1ethods used Btshop simpldied Janbu simplified Spencer 1"<---------------i1:::::?1J---------------t .,., . ... 0200 .,., e ,oo STATIC STABI LIT Y AFTER GROUND IMPROVEMENTS : STONE COLUMNS -NORTH ABUTMENT BLACK RIVER BRIDGE LAK E TO SOUND TRAIL PROJECT NO 2010-100-21 ! ' ! § S•!dy F•ct-or .. 0 .000 0 .500 1.000 1 .500 2 .000 2 ,500 3 .000 3 .500 4.000 -t .~oo S.000 5.500 6 .000+ FIii Strength Type · Mohr.Coulomb Uni Weight · 130 lblft3 CohesK>fl· O psf Fnctioo Angle. 36 dogrees Wa1e1 Suri.le, Waler fable Loose Sand Sueogth Type Mohl-Coulomb Un< Weigh! 110 lb/113 Cohesion. 1 psf Fnction Angl e· 28 degree s Wate r Sutface Wa1e1 Table Medium Dense AJh.Mum Strength Type · Mohr.Coulomb Uni We;gt,1 124 lb/113 Cohes,on: 1 psf Fnction Angle. 35 deg,ee'.I Water Surface· Waler Tab(e .... Project Number 2010-100-2 1 Task 200 Project Namt: 81ac.k Riwr Bndge Lake 10 Sound Tral Renton, Washington SolJth &de· Pseudo.Static Analysis Mer Ground lmpn1trement s (0.ep S0<I Mixing) Glaci8'T1II Strength Type: Mohr-Coulomb Unn Weight. 134 lb/113 Cohesion: 1 pst Frie.Mn Angle 36 degrees Water Suiface Wster Table Improved Materi8' Sllenglh Type. Mohr-Coulomb Unn Weight 120 lb/11 3 Cohesion: 2000 ps1 Friction Angle . 32 degrees Water Surface· Wal.er Ta bl e ... , o,oo .. ,. ::rw I HWAGmsc,E NCEs INC . ... .... ~110 ST ATIC STABI LI TY AFTER GROUN D IM PROVEMENTS: DEEP SOI L M IX IN G -SOUT H ABUTM ENT BLACK RIVER BRIDG E LAKE TO SOUND T RAIL PROJECT NO 2010-1 0 0-21 ! ! ~ § ~ Sa!ny r a c:t o i: 0 ,000 0.500 1.000 Pro,ect Number 2010-1 00-21 Task.200 P,ot9ct Nsme Black Rive, Sndge 1.5-00 2 .000 Lakt t o Sound Trail Renton . Washington ,.soo 3.000 North SHie Pseudo·Stahc Analysis M er Ground lmprovemems {De ep So,I Moxing) 3.500 ,.ooo ,.soo S.O<IO 5 .SOO 6.000+ 6 100 Fdl Streng1h Type Mohr-Coulomb Unn Weight· 130 lblft3 Coheston O ps f FncllonAngle. 36 deg,ees Water Sutface Water Table l oose Sa~ Strt ngth Type M ohr-Coulomb Unn We,ght 110 lb/113 Cohesion 1 psf friction Angle 28 de,grees Wa1a1 Sortace Waler Table Medium Dense AlllMum Strength T1'PO Moht.Coulomb Unrt We;gt-< 124 lblllJ Cohesion 1 psf Fnc1ionA.n9'e 35 deg,ees Wa1 er Surface Water Table .. ,. .... G1~1:alTill Stiength Type Motu-Coolomb Unn Wetgnt· 134 lb/ft) Cohesion 1 psf Fnct1on Angl e 36 deg,ees Wa1e, Surtace Wmtr Tablt S.d Roc k Strength Type· M ohr.Coulorrib Unn Weight 14S lblft3 Cohesion 1 psf FnctionAngle 4S degrHs W mer Surface Water Table Improved Malena! Strength Typo Mohl-Coulomb Unn Weigh• 120 lblftJ CoheslOI\ 2000 psf Fnction Angle 32 degrees Water Surtace Watu Tabl e .... ~110 IJW I HWA GEOSCIENCES INC. !De nse Glacial Ti!! ..,,. An,tys,s: Methods used B ishop simphfied Janbu $1mpltfled Spenctr 030 STATIC STABILITY AFTER GROUND IMPROVEMENTS: DEEP SOIL MIXI NG -NORTH ABUTMENT BLACK RIVER BRIDGE LAKE TO SOUN D TRA IL PROJECT NO 2010 -100-21 Sa.re~y fac'tOr 0.000 ! o.soo 1.000 LSOO ! 2.000 2.soo 3.000 3.500 ¥ ,.ooo ,.soo S.000 § S.500 6 .000+ ! ~ ~ ~ § Fill Strength Type Mohr-C oulomb Uno Weigh1 · 130 lb/113 Cohe&1on· O pst Friction Angle 36 degrees Water Surface· Water Table loose Sand Strength Type Mohr-Coulomb Uno Weight · 110 lblll3 Cohesion: 1 ps:f Friction Angie. 28 degrees Water Surface· W3ter Table Medium Dense Alluvium StrengJh Type Mohr-Coulomb Unn Wei9h1 : 124 lblft3 CoheSton. 1 psf Friction Ang.e. 35 degrees Water Surface. Water Table .... .... Projeet Number: 20 10-100-21 Task:200 Pro1ect Name Black Rive, Bridge Lake to Sound Trail Renton. Washington So'"h Side Pseudo Static Analysis After Ground lmp,OWtments (Stone Columos) Glacial Till StrengJh Type. Mohr.Coulomb Uno Weigh1: 134 lblll3 Cohe,i9n: 1 p,f Friction Angle. 36 degree s Wa!.tr Surface . Water Table Improved Material Strer,glh Type . Mohr-Coulomb Unn Weigh1 . 11 5 lblll3 Cohes,on 1 psf Fnchon Angle. 32 degree s Water Surface Wa1 er Tabte .... ., .. 01'0 n~, I HWA crnscrENCE s INC. 01<0 ., .. !Medium Dense Allooum! e.110 .... PS EUD O STATI C STABI LI TY AFTER GROUND IMPROVEMEN TS : STON E COL UM NS-SOUTH ABUTM ENT BLAC K RIVER B RIDGE LAK E T O SO UND T RAI L .. PROJECT NO 2 010-100 -2 1 .. ~ ~ ! § ~ Sa!r:ty fa c t or 0.000 o.soo Project Numbet 2010-100-2 1 Task:200 Project Name · Bleck River Bndge 1.000 Lake to Sound Tr ail Renton . Washingt on 1.500 2.000 Nonh Side Pseudo-5tattC Anatys1s Afte, Ground lmiwovements 2.500 (Slone Columns ) 3.000 3.500 L OOO 4. soo S.000 s. soo 6 .MO+ 0100 Fill Streng1h Type Mohr-Coulomb Urnt Weogt,, 1 JQ lblllJ ~sion Ops! Friction Angle. 36 degrees Wa1e1 Surface:. Water Table loose Sand S1teng1h Type · Mohr-Coulomb Unit Weight 11 0 lb/113 Cohesion . 1 psf Friction Art<}e 28 deg,ees Water Surtac e Waltr Table Me<fium Dense Alh.Mum S1 reng1h Type : Moh,-Coulomb Uni! W eight 124 lt.'113 Cohesion 1 psf Frict ion ~e 35 degrees Water Surface · W.Jt.er Tabl e 01'0 ..... Glaci al Till S1reng1h Type Mohr-Coulomb UM Weight· 134 11>'11 3 Coheo oOI\ I psf Fncl1on Angle 36 degrees Waler Surface Watef Tabte Bed Rock S1reng1h Type Mohr -Coul om b Uno Weight · 145 lblll3 Cohe sion-1 psf Fnct1on JJ,.rt<je· 45 degrees Waler Surface Wal e, Table lmp,oved Mal enal S1reng1h Type . Moh1-Coulom b Uno! Weight 115 lblll3 Cohesion. 1 psf Friction Angle. 32 degrees W aler Surfac e Water Table o,eo e1 10 ::r~, I HWAGEOSCIEN CES IN C. I Loo se Sand I !Den se Glacial nnj .... 0210 0300 PSEUDO STATI C STABILITY AFTER GROUND IMPROVEMENTS STONE COLUMNS-NORTH ABUT MENT BLACK RIVER BRI DGE LAKE TO SOUND T RAIL PFIOJEC-NO 2010 -100-2 1 !! S•t'~ty F•ctor 0.000 0.500 1 .000 1 .SOO 2,000 '2 .500 3.000 3.SOO (.000 •l.500 s.ooo 5.SOO 6.000+ ~ ~ ~ ~ ~ 0000 .... Fil St1ength Type: M-0111-Coulomb Unn W191t 130 lblftJ Cohesion . O psi Fricuon Angl o· 36 degrees Water Surface· Waler Table Loose Sand St1ength Type · Mohr.Coulomb Uno Weight 110 lb/113 Cohesion 1 psf Friction Angle 28 deg,ees Water Surface Water Tabl e Medium Oe nH Alluvium Strength Type· Moh r.Coulomb Un( Weight: 124 lblft 3 Cohesion 1 psi Friction Angle· 35 degree s Waler Sufface: Water Table .... .... Ir~ I HWA GEOSCIENCES INC. P,oject Number: 20 10 -100-21 Task·200 P,oject Name Black River Bndge Lake lo Soood Trail Renlon . Was hington Soulh Side: Pst-udo-Stat ic. Analysis Aft er Ground lmprOYements (Deep Soil Mixing) Glacial Till S1Jength Type : Mohl -Coulomb Unrt Wei9h1 · 134 lb/113 Cohts,on· 1 psi Friciioo Angle: 36 deg<••• Wate1 Surface. Water Table lmprowd Maenal Strength Type· Mohr-Coulomb U,,,t Weight. 120 lb/113 Cohesion· 2000 psf Friction Angle · 32 degree s Wttttt Sutface . Water Table .... . , 0 120 .... Midtum Dense Alll.Nium .... eu o 0220 PSEUDO STATIC STAB I LITY AFTER G RO U ND IMPR OVE MEN TS : DEEP SOI L M IXIN G. SOU TH A BUTMENT BLAC K R IVER BRI DG E LAKE TO SO UN D T RAIL , .... PROJECT NO 201 0-100 -21 •' . •• Pro1ect Numbe, 2010-100-2 1 Task·200 Pro1ect Name Black RNer Bndge Lake to Sound Trail Renton W ashington North Side Pseudo-Stahc Analys is Aft er Gtound lmprovemenls (Deep Soll Muong) Fill Srrengih T\1)0 Mohr-Coulomb Unn we,ght 130 11>'113 Cohesion: 0 psf Fnction A.ngle 36 degrees Water Surlace· Water Table Loose S.nd Strength Type Moh<-Coufomb Unrt We,ght t 10 lblft3 Cohesion t psi Friction Angle 28 de9'ees W ater Surface Water T;1bfe Medium Dense AU\Mu m Strenglh Type . Mohr-Coulomb Unit Weight 124 lbffl) Cohesroo 1 psf Fnct1on Angle 35 degrees Water Surface Water Table 0120 0 1'0 Glacial Till St,ength Type Mohr-Coulomb Unn We1gh1· 134 lblft3 Cohesion· 1 psf f nct1onAng.e 36 degree, Wate r Surface· Wate, Table Bed Rock Sl rengih Type Mohr-Coulomb Unn Weight 145 11>'113 Cohe$10ff 1 psi Fnclion Angle 45 degrees Water Surface· Wal er Table lmpor•;ed Material Strength Type Mohr-Coulo mb Unrt W.,ght. 120 11>'113 Cohesion 2000 psf Fnclion Angle 32 degrees Water Surface Water Ta bfe 0 100 e ,10 :r~, I HWA GEOSCI ENCES [NC. 0200 !Dense Glacial Till! i.---------------~,t~l----------------..i .,., 0 )00 PS EUDO STATIC STABILITY AFTER GRO UND IMP ROV EM ENTS DEE P SOI L MIXING -NORTH ABUTME NT BLAC K R IVER BRIDGE LAKE TO SO UN D TRA IL ~om PROJECT NO 2010-1 00-2 1