HomeMy WebLinkAboutSWP272797 Shod Plat (SHPL•# ) .
REQUEST FOR PROTECT# Prelim.Plat (PP#
CAG# )
To: Technical Services Date :77/1 q I WO# 870 S I Green#
From: Plan Review/Project Manager >1• K T-Tva,Ue.
Project Name 5TAFwftD CZFST D1V a
(70 characters a=)
Description of Project: ?l A7- 1gY-oVEMGPTS 1AlCe vn 1A)(, STORM DR.glNA§& 10A A �, �57�
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Circle Size of Waterline: 8" 10" 12" Circle One: New or Extension
Circle Size of Sewerline: 8" 10" 12" Circle One: New or Extension
Circle Size of Stormline: 0 15" 18" 24" Circle One: ew or Extension
Address or Street Name(s) Ne 3Lil-" STR-er-r L NICOL1J AV 1.1E
Dvlpr/Contractor/Owner/Cnslt:: 6)Izoup `-I /NC. -
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Check each discipline involved in Project Ltr Drwg #of sheets per discipline
E� Trans-Storm CCY C
(Road way(Drainagc) (Off site improvcmcnts)Onclude basin name) (include TESC sheets)
I� Transportation (Signalizaaon,Channclization,Lighting) `1
❑ Wastewater ❑ ❑
Sanitary Sewer Main(nclude basin name)
Cl Water (Mains,valves,Hydrants) ❑ ❑ �—
(include composite&Horizontal Ctr1 Sheets)
Gy`� Suface Water ix
Improvements (CIP ONLY)(includc basin name)
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GEOTECHNICAL REPORT
XJ
Stafford Crest Division 2
NE 36th Street and 109th Place NE
Renton, Washington
Project No. T-3685-3
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2E4 Terra Associates, Inc.
bb� pppyyy p t¢ .. 4
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Prepared for:
Stafford Homes
Bothell, Washington
XXX
June 30, 1998
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ag: P
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ConSuitants ir?Gcolechnical Engi1-1ce.HrV,, Geology
and
Environmental Earth ScienccE
January 8, 1999
Project No.T-3685-3
Mr.Randy Skyles
Stafford Homes
16016-- 118th Place NB
Bothell,Washington; 98011
Subject: Building Slope Setback
Stafford Crest,Division:2
Renton,Nashington
Reference: Geotechnical Deport, 'Sniff ord Crest,Division?, prepa:rd by Cerra Associates, Inc., Prr?ject No.
T-3685-3,dated June 30, 1998.
Bear Randy:
As requested, we have completed additional review of stability conditions cri the west-facing slopes at the above
subject site. The purpose of our review was to determine if, in our opinion, it would be;possible to encroach upon
the?5-foot building setback.line(BS13L) froiT..i the slope crest that is carrentl;i shown on the grading d�`.iid�la Iecdt
discussed in the referenced report, To comp'icte ou; review, we again visi,'.ed the sits and perfo
reconnaissance of the existing slope conditions. We also requested,, :ind were supplied with, additional
topographic information fi•orn Group Fou.,,Inc:,
Based oa our additional evaluation, we do not recommend encroaching bc-ond the 25-•foot BSBL wish building
construction. All buildings and associated .structures should be loes.ted .;ist and otrt:;ide of this zone. In our
opinion, it will be possible to clear and coj`r1plLte some limited grading; 4vork within t:he first 1S f4.et of this
building setback,zone, provided free and positive surface drainage away frorra the;slope crest is maintained and the
surface revegetated to prevent erosion. Orading should be limited to exc: .vation and no fill material should be
placed within the I3SB3.. Ake;' cot:npcneni in main the existing s!.;i.bility and lyrevettting impacts w'tl1 be
noff n.tirst not be �allowcd to Clow uncat7trolled over the •,rest of the
control of surface drainage. Surface water ru
slope or on the slope face. Where necessary, a system of yard drains should be installed within this 1.5-foot zone
to collect surface runoff and direct it to a point of controlled and approvf:d dischar-,c. The irnmediate ten feet
adjacent to the slope crest should be maintained as a.buffer and left undisturbed.
12525 \/Willows Road, `quite 101, Kirkland, Washington 980:4 • p1lone 425) 821-7777
a :s�l?easesoa — -=�sio—eci� son : WVOV:c
Mr. Randy Skyles
January 8, 1999
In our opinion, with development of the site adjacent to the slope crc:its completed as described above and
discussed in the referenced report, there would be no adverse impacts.to the currem stability of the slopes on or
adjacent to the sitc. However, it m.u;yt be recognized that with all su �p slopes thot'c is an inherent risk of
instability and, however minimal, must he mcognizcd and assumed by the property owner. In our opinion, the 25-
foot building setback line would adequately rrdtigatc the risk to bLdldirg construction. 'However, the risk for
continued regression of the slope cr:st back into the;property remains.
We trust the information presented. is sufficierit for your current need.. if you 11.tte any question;, or require
additional information,please call,
W4.4
Sincerely yours,
TERRA ASSOCIAT
vlleo-d-ore J. Sche t er, AN 287Q :•
Principal Engin ter
ASS '
TJS;dvp q'+R
cc, Mr. Bill ;Staffc,�r�i I oiPir��
Mr. Bob Stokke, Stafford Homes
Project No, T-3685-3
Page No. 2
ltr 90Z L W`dtr.L B6—i1i' .? �IVI '8f10� d(1Qa�J:J9 11�8
TERRA ASSOCIATES, Inc.
Consultants in Geotechnical Engineering, Geology
4.. and
Environmental Earth Sciences
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t
June 30, 1998
E Project No. T-3685-3
Mr.Rob Purser
Stafford Homes
16016 - 118th Place NE
Bothell, Washington 98011
Subject: Geotechnical Report
Stafford Crest Division 2
NE 36th Street and 109th Place NE
Renton, Washington
Dear Mr. Purser:
As requested, we have conducted a geotechnical engineering study for the subject project. The attached report
presents our findings and recommendations for the geotechnical aspects of project design and construction.
Our field exploration indicates the site is generally underlain at shallow depths by medium dense to dense silty
sand. It is our opinion that the single-family residences may be constructed using conventional spread footings
f placed on competent native soils or on structural fills. Slab-on-grade floors and pavements may be similarly
supported.
We trust the information presented in this report is sufficient for your current needs. If you have any questions
or require additional information,please call.
Sincerely yours,
TERRA ASSOCIATES,INC.
UGC 'h
David P. Laush �s
Staff Geologist
Theodore J. Sche r, E.
Principal Engineer 21 {4F
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cc: Mr. Steve our, Inc.
." �6/1
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12525 Willows Road, Suite 101, Kirkland, Washington 98034 • Phone (425) 821-7777
TABLE OF CONTENTS
Pace No.
1.0 Project Description..................:...................................................................................... 1
2.0 Scope of Work................................................................................................................ 1
3.0 Site Conditions............................................................................................................... 2
3.1 Surface............................................................................................................... 2
3.2 Soils................................................................................................................... 2
3.3 Groundwater...................................................................................................... 3
4.0 Geologic Hazards ..,.................._..................................................................................... 3
4.1 Erosion.................:............................................................ ............................... 3
- 4.2 Seismic .............................................................................................................. 3
4.3 Slope Stability................................................................................................... 4
5.0 Discussion and Recommendations.._.............................................................................. 4
5.1 General .............................................................................................................. 4
5.2 Site Preparation and Grading............................................................................ 4
5.3 Structural Fill.............................................................._...................................... 5
5.4 Slopes and Embankments.................................................................................. 5
5.5 Excavations ...................................................................................
5.6 Foundations......................................................................_................................ 6
5.7 Slab-on-Grade Construction.............................................................................. 7
5.8 Lower-Level Walls and Retaining Walls.......................................................... 7
5.9 Stormwater Facilities......................................................................................... 7
5.10 'Rockeries........................................................................................................... 8
5.11 Drainage ............................................................................................................ 8
5.12 Utilities.............................................................................................................. 9
5.13 Pavements.......................................................................................................... 9
6.0 Additional Services...................................................................................................... 10
7.0 Limitations.................................................................................................................... 10
Figures
Vicinity Map ..................................................................................Figure 1
Exploration Location Plan.................................................................. .............................Figure 2
Retaining Wall Drainage Detail..........................................................................................Figure 3 I
Rockery Cross-Section ..............................:........................................................................Figure 4 ;
Reinforced Fill/Rockery Cross-Section................................................. .Figure 5
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Appendix
Field Exploration and Laboratory Testing................................... ......... ..:..... ..........Appendix A
�1)
Geotechnical Report
Stafford Crest Division 2
NE 36th Street and 109th Place NE
Renton, Washington
1.0 PROJECT DESCRIPTION
The project consists of a multi-lot development for single-family residences with associated utilities and
roadways. Access to the plat will be from NE 35th Street and NE 33rd Place, both located on the east side of
Division 2. Both roads will be constructed during the development phase of Division 1. The Division 2 dots will
mainly be served by a single road, 109th Place NE, which ends in a cul-de-sac. Site grading proposed to
establish lot and roadway grades will consist primarily of cuts varying from two to six feet on the east portion of
the site,to structural fills approaching ten feet on the west portion of the site. Rockery construction is proposed
to accommodate a grade break on the back of Lots 3 through 9, with heights approaching eight feet. A 25-foot
building setback line is proposed from the crest of the 40 percent slopes that adjoin the west property line.
Stormwater facilities will include a detention vault constructed on Tract A in the northwest corner of the site.
Treated stormwater will be discharged through a control structure to an off-site drainage system that will follow
existing roads. The new system will drain west on NTE 36th Street, where it will flow down the west slope from
NE 36th Street in a Drisco pipe to the discharge at Jones Avenue.
Based on our experience with similar projects, we expect the residential structures will be supported on a system
of bearing walls and isolated columns. Main floor levels will be framed over a crawl space, with garage floors
constructed as slabs-on-grade. We expect structural loads to be about 1 to 2 kips per foot for bearing walls and
about 20 kips for interior columns.
The recommendations contained in the following sections of this report are based on our understanding of the
above design features. If actual features vary, or changes are made, we should review them in order to modify
our recommendations as required. We should review the final design drawings and specifications to verify that
our recommendations have been properly interpreted and incorporated into project design and construction.
2.0 SCOPE OF WORK
From June 19, 1997 to June 11, 1998, we explored the site soils by excavating 37 test pits to depths from 6 to 20 c
feet below existing grades. Of these 37 test pits, 14 of the test pits were found to lie within or near the boundary
of Division 2. Using the information obtained from the subsurface exploration, we performed analyses to
develop geotechnical recommendations for project design and construction.
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June 30, 1998
Project No. T-3685-3
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Specifically, this report addresses the following:
• Soil and groundwater conditions
• Site preparation and grading
• Suitability of native soils for use as fill
• Recommendations for import fill material
• Slopes, embankments, and excavations
1
• Foundation support
• Slab-on-grade support
• Stormwater facilities
• Rockeries
• Drainage
• Utilities
3.0 SITE CONDITIONS
3.1 Surface
The project site is located southwest of the intersection of NE 36th Street and 110th Place SE in Renton,
Washington, as shown on the Vicinity Map, Figure 1. The property has gross dimensions of 415 feet by 950 feet.
In general, the site slopes gently down from Elev. 270 in the southeast corner to Elev. 215 in the central
northwest corner. A greater than 40 percent slope is located on the west perimeter.
The property is bordered on the west, south, and east by scattered residences and undeveloped land. May Creek
is located 500 to 1,000 feet south and west of the site. Site vegetation consists of maple, alder, and cottonwood
trees, and low-growth vegetation consisting of blackberries and stinging nettle.
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3.2 Soils
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On the site, surficial organic topsoil and forest duff range in thickness from 6 to 18 inches. We generally
encountered roots at two to three feet below grade, with occasional isolated roots to five feet. Underlying the
topsoil, we encountered medium dense to dense, fine silty sand over most of the site to the depths explored. In a j
few of the deeper excavations, we encountered glacial till consisting of very dense silty sand to silty sand with
gravel from 12 to 20 feet.
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Page No. 2
r June 30 1998
Project No. T-3685-3
A more detailed description of the subsurface conditions encountered is presented on the Test Pit Logs in
Appendix A. The Exploration Location Plan, Figure 2, shows the approximate test pit locations.
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3.3 Groundwater
With the exception of Test Pit TP-10 on Tract A of Division 1, we did not observe groundwater seepage in our
test pits. At Test Pit TP-10, we observed light seepage at a depth of 14 feet. This depth corresponds with the
depth where relatively dense till-like soils were observed. Fluctuations in groundwater seepage levels should be
expected on a seasonal and annual basis. The amount of seepage will be highest during extended periods of
heavy precipitation and during the wet winter months.
4.0 GEOLOGIC HAZARDS
4.1 Erosion
The subject property is mapped in the Soil Survey of King County Area, YYashington, (U.S. Soil Conservation
Service) as Alderwood gravelly sandy loam. This classification is not consistent with soils we observed over
most of the site. In our opinion,the soils would be more representative of the Ragnar soil series, which is also
mapped north of the site. These classifications are consistent with the soils we observed. With the existing slope
gradients over most of the site, these soils will have a low to moderate potential for erosion when exposed.
Where site gradients increase, the soil erosion potential will be high. Erosion protection measures, as required by
the City of Renton, will need to be in place concurrent with the start of grading activity on the site.
4.2 Seismic
The Puget Sound area falls within Seismic Zone 3, as classified by the 1994 Uniform Building Code(UBC).
Based on the soil conditions encountered, and the local geology from Table 16-7 of the UBC, a site coefficient of
1.2 should be used in design.
Liquefaction is a phenomenon where there is a reduction or complete loss of soil strength due to an increase in
water pressure induced by vibrations. Liquefaction mainly affects geologically recent deposits of fine-grained
sands that are below the groundwater table. Soils of this nature derive their strength from intergranular friction.
The generated water pressure, or pore pressure, essentially separates the soil grains and eliminates this
intergranular friction, thus eliminating the soil's strength. Based on the soil and groundwater conditions we
encountered, it is our opinion that there is no risk for liquefaction to occur at this site during an earthquake.
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Page No. 3
June 30, 1998
Project No. T-3685-3
4.3 Slone Stability
We did not observe site conditions that would indicate unstable.slope conditions exist at the site. Slope
conditions observed on the western slopes were stable and there was no surficial evidence that previous,slope
failure had occurred at the site. The soil conditions encountered at the test pits exhibit moderate to high strength
characteristics. In our opinion, provided recommendations outlined in this report are followed, the planned
grading and a minimum building setback of 25 feet from the slope crest, as allowed by the City building code,
would not impact the current stability of the site slopes nor those on adjacent properties.
5.0` DISCUSSION AND RECOMMENDATIONS
5.1 General
Based on our study, in our opinion, there are no geotechnical considerations that would preclude site
development as planned. The residences may be supported using conventional spread footing foundations
bearing on competent native soils below the upper 12 to 18 inches of surficial soils or, if required, on compacted
structural fill. Pavements and floor slabs may be similarly supported.
The native soils encountered at the site contain a significant amount of fines and when wet will be difficult to
compact as structural fill. The ability to use native soil.from site excavations as structural fill will depend on its
moisture content and the prevailing weather conditions at the time of construction. If grading activities will take
place during the winter season, the owner should be prepared to import clean granular material for use as
structural fill and backfill.
Detailed recommendations regarding the above issues and other geotechnical design considerations are provided
in the following sections. These recommendations should be incorporated into the final design drawings and
construction specifications.
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5.2 Site Preparation and Grading
In areas receiving fill, and below pavements, slabs, and foundations, it will be necessary to strip and remove
vegetation and organic surface soils. Based on our study, surface stripping depths of 6 to 18 inches should be
expected to remove the organic topsoil. Stripped vegetation should be removed from the site. Organic topsoil j
will not be suitable for use as structural fill,but may be used for landscaping purposes.
Prior to placing fill and to prepare building and pavement subgrades, we recommend proofrolling all exposed
surfaces to determine if any isolated soft and yielding areas are present. If excessively yielding areas are
observed, they should be recompacted in place or overexcavated to expose firm bearing soil and replaced with
structural fill to finalgrade. We should observe all proofrolling operations.
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Page No.4
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June 30, 1998
Project No. T-3685-3
Competent bearing material for building foundations should consist of medium dense to dense native soils. It
may be necessary to carry the foundations deeper through the loose surficial soils and root mat to expose
competent subgrade material. Foundations may also be placed on properly placed and compacted structural fill.
Slab-on-grade floors and pavements may be constructed on any native inorganic soil that is first compacted to a
non-yielding condition or on compacted structural fill as needed. A representative of Terra Associates, Inc.,
should perform field evaluations at the time of construction to verify stable subgrades.
5.3 Structural Fill
Our study indicates that most of the native soils contain a moderate percentage_of fines (silt size particles). In
general,the inorganic silty sand excavated on-site will be suitable for reuse as structural fill material;provided it
can be properly placed and compacted. However, the ability to use the native soils as structural fill or backfill
will depend on their moisture contents and the prevailing weather conditions when site grading activities occur.
Moisture conditioning may be necessary depending on the silt and moisture content of the material.
If site grading takes place during the wet.winter season or begins in the fall and extends into winter, it may be
necessary to import suitable wet weather structural fill. For this purpose, we recommend importing a clean
granular material that meets the following grading requirements.
U.S. Sieve Size Percent Passing
3inches 100
No. 4 75 maximum
No.200 5 maximum*
*Based on the 3/4-inch fraction.
Before use, Terra Associates, Inc., should examine and test all materials imported to the site for use as structural
fill.
Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of
95 percent of the soil's maximum dry density, as determined by ASTM Test Designation D-698 (Standard
Proctor). The moisture content of the soil at the time of compaction should be within two percent of its
optimum, as determined by this ASTM standard. In non-structural areas, the degree of compaction could be
reduced to 90 percent.
5.4 Slopes and Embankments
All permanent cut and fill slopes should be graded with a finished inclination of no greater than 2:1
(Horizontal:Vertical). When grading is complete, slope faces should be thoroughly compacted and track-walked
and then appropriately vegetated or provided with other physical means to prevent erosion. All fill placed for
embankment construction should meet the requirements described in the Structural Fill section of this report.
Subgrades should be prepared as discussed in the Site Preparation and Grading section of this report.
Page No. 5
June 30, 1998
Project No. T-3685-3
Final grades at the top of the slopes must promote surface drainage away from the slope crest. Water should not
flow uncontrolled over the slope face. If it is necessary to direct surface runoff towards the slope, it should be
controlled at the top of the slope, piped in a closed conduit or an appropriately lined channel installed on the
slope face, and taken to an approved point of discharge beyond the slope toe.
5.5 Excavations
All excavations at the site associated with confined spaces, such as utility trenches and lower building levels,
must be completed in accordance with local, state, or federal requirements. Based on current Occupational
Safety Health Administration (OSHA) regulations,the majority of the site soils consisting of silty sand outwash
would be classified as Group C soils.
For excavations more than 4 feet and less than 20 feet in depth, side slopes should be laid back at a minimum
slope inclination of 1.5. If there is insufficient room to complete excavations in this manner, you may need to
consider using temporary shoring to support the excavations.
The above information is provided solely for the benefit of the owner and other design consultants, and should
not be construed to imply that Terra Associates, Inc., assumes responsibility for job site safety. It is understood
that job site safety is the sole responsibility of the project contractor.
5.6 Foundations
Foundations may be supported on competent native soils or on structural fills that have been placed and
compacted on competent native soils, as described in the Site Preparation and Grading section of this report.
Foundations exposed to the weather should be a minimum of 18 inches below final exterior grades. Interior
foundations can be constructed at any convenient depth below the floor slab.
Foundations can be dimensioned for a net allowable bearing capacity of 2,000 pounds per square foot(psf). For
short-term loads, such as wind and seismic, a one-third increase in this allowable capacity can be used. With
structural loading as anticipated and this bearing stress applied, estimated total settlements are about one inch
and less.
For proportioning foundations to resist lateral loads,a base friction coefficient of 0.4 can be used. Passive earth
pressure development acting on the sides of the footings and buried portion of the foundation stem walls can also
be considered. We recommend calculating this lateral resistance using an equivalent fluid weight of 350 pounds
per cubic foot (pcf). We recommend not including the upper one foot of soil in this computation because it can
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be affected by weather or disturbed by future grading activity. This value assumes the foundation will be
constructed neat against competent native soil or backfilled with structural fill as described in _the .Site
Preparation and Grading section of this report. The passive value recommended includes a safety factor of 1.5.
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June 30, 1998
Project No.T-3685-3
5.7 Slab-on-Grade Construction
Slab-on-grade floors may be supported on a subgrade prepared as recommended in the Site Preparation and
Grading section of this report. Immediately below the floor slab, we recommend placing a four-inch thick layer
of clean, free-draining sand or gravel that has less than three percent fines passing the No. 200 sieve. This will j
prevent wetting of the floor slab due to capillary movement of water through the underlying soil. Where
moisture by vapor transmission is undesirable, a durable polyethylene vapor barrier should also be installed.
This vapor barrier should be placed on the capillary break layer and then covered with two inches of clean sand
to prevent damage during construction and to aid in uniform curing of the concrete floor.
5.8 Lower-Level Walls and Retaining Walls
The magnitude of earth pressures developing on lower-level,walls or retaining walls will partly depend on the j
wall backfill. We recommend placing and compacting wall backfill as structural fill. To prevent development of
hydrostatic pressure, subsurface drains must be installed behind all walls. Figure 3 shows a typical
recommended retaining wall drainage detail.
With proper wall backfill and drainage, we recommend designing unrestrained walls for an active earth pressure
imposed by an equivalent fluid weighing 35 pcf For restrained walls, an additional uniform lateral pressure of
100 psf should be added. These values assume a horizontal backfill condition and that no other surcharge
loading, such as traffic, sloping embankments, or adjacent buildings, will act on the wall. If such conditions will
exist, the imposed loads must be included in the wall design. Friction at the base of foundations and passive
earth pressures will provide resistance to these lateral loads. Values for these parameters are provided in the
Foundations section of this report.
5.9 Stormwater Facilities
As noted earlier, based on soil texture, we believe the SCS soil classification at the site would be Ragnar, as
opposed to Alderwood. However, based on extensive infiltration testing, the permeability of the soils is
indicated to be relatively low. Therefore, for analysis and design of stormwater facilities, we recommend using
Hydrologic Soil Group C.
A stormwater detention vault will be constructed on Tract,A in the northwest corner of the site. At this time, we
were not provided with any details for constructing the vault. We expect the vault will bear at a depth of six to
ten feet below existing grade. Our field exploration indicates that the soil conditions encountered in the vault
area should consist of medium dense sandy silt to dense silty sand.
The vault foundation can be designed using the parameters recommended in the Foundations section of this
report. Given the expected vault depth, its foundations, can be designed for an allowable bearing capacity of
5,000 psf. The magnitude of earth pressure development on the vault walls will partly depend on the quality of
the wall backfill. We recommend placing and compacting wall backfill as structural fill. To guard against 4
hydrostatic pressure development,wall drainage must be installed.
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Page No. 7
June 30, 1998
Project No. T-3685-3
With wall backfill placed and compacted as recommended and drainage properly installed, we recommend
designing unrestrained walls for an active earth pressure equivalent to a fluid weighing 35 pcf. For restrained
walls fixed only at the top, the wall should be designed for an effective fluid pressure of 50 pcf. These values
assume a horizontal backfill condition and that no other surcharge'loading, such as traffic, sloping embankments,
or adjacent buildings,will act on the walls.
We understand that stormwater from the vault will be discharged through a Drisco pipe, surface-mounted on the
western slopes. Based on our observations, it is our opinion that installation of the pipe would have no adverse
impacts on the stability of the slopes provided:
a) Clearing is restricted to the pipe alignment.
b) Areas of exposed soils are revegetated or provided with other covering to mitigate potential erosion.
c) The Drisco pipe is installed in accordance with the manufacturer's recommendations.
5.10 Rockeries
We understand rockeries will be used as grade breaks for the back of Lots 3 through 9 on the site. A rockery is
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not intended to function as an engineered structure to resist lateral earth pressures as a retaining wall does. The
primary function of a rockery is to cover the exposed excavated surface and thereby retard the erosion process.
Soil conditions encountered in most of our test pits indicate loose to medium dense sandy silt to silty sands,over
dense, silty sands.
The loose to medium dense silty sands will not stand near-vertical for rockery construction. If rockeries are
facing the silty sand soils with heights greater than four feet, we recommend excavating out the silty sands and
reconstructing the area as a reinforced structural fill rockery. Rockeries of four feet and less can be constructed
against the loose,to medium dense silty sands without reinforcement. We recommend limiting rockeries to a
height of eight feet where placed against the dense silty sand soils and against the reinforced fill section. Typical
rockery construction details are included on Figures 4 and 5.
The construction of rockeries is, to a large extent, not entirely controlled by engineering methods and standards.
It is imperative that rockeries are constructed properly and with care. An experienced contractor, with a proven
ability in rockery construction, should perform the work. The rockeries should be constructed with hard, sound,
and durable rock in accordance with accepted local practices.
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5.11 Drainage
Final exterior grades should promote free.and positive drainage away from the building sites at all times. Water
must not be allowed to pond or collect adjacent to foundations or within immediate building areas. In addition,
surface water must not be directed to discharge towards the western site slopes. Runoff from roofs and yards
should be collected and tightlined to the development stormwater'facilities. f
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June 30, 1998
Project No. T-3685-3
We recommend providing a minimum drainage gradient of three percent for a minimum distance of ten feet from
building perimeters, except in paved locations. In paved locations, a minimum gradient of two percent should be
provided unless provisions are included for collection and disposal of surface water adjacent to the structures.
Roof gutter drains should be tightlined away from the structure and not tied to the wall or perimeter foundation
drains. Drains and surface runoff collected from impervious surfaces should be tightlined to discharge at an
approved location, taking care not to impact adjacent slopes and properties.
5.12 Utilities
Utility pipes should be bedded and backfilled in accordance with American Public Works Association (APWA)
or City of Renton specifications. At a minimum, trench backfill should be placed and compacted as structural
fill, as described in the Structural Fill section of this report.
5.13 Pavements
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Pavements should be constructed on subgrades prepared as described in the Site Preparation and Grading section
of this report.. However,regardless of the degree of relative;compaction achieved, the subgrade must be in a firm
and relatively unyielding condition prior to paving. The subgrade should be proofrolled with heavy construction
equipment to verify this condition.
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The pavement design section is dependent on the supporting capability of the subgrade soils and the traffic
conditions to which it will be subjected. For traffic consisting mainly of light passenger and commercial
vehicles, with only occasional heavy traffic in the form of moving trucks and trash removal vehicles; and with a
stable subgrade prepared as recommended, we recommend the following pavement sections:
• Two inches of asphalt concrete(AC) over six inches of crushed rock base (CRB)
Two inches of AC over four inches of asphalt treated base(ATB)
Paving materials used should conform to Washington State Department of Transportation (WSDOT)
specifications.
Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be
subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their
supporting capability. For optimum pavement performance,we recommend surface drainage gradients of no less
than two percent. Also, some degree of longitudinal and transverse cracking of the pavement surface should be
expected over time. Regular maintenance should be planned to seal cracks when they occur. j
j
1
i
Page No. 9
i
i
June 30, 1998
Project No. T-3685-3
6.0 ADDITIONAL SERVICES
Terra Associates, Inc., should review the final design and specifications in order to verify that earthwork and
foundation recommendations have been properly interpreted and incorporated into the project design and
construction. We should also provide geotechnical services during construction in order to observe compliance
with the design concepts, specifications, and recommendations. This will allow for design changes if subsurface
conditions differ from those anticipated before the start of construction.
We request a notice of two working days minimum be given to schedule our services during construction.
7.0 LIMITATIONS
This report is the property of Terra Associates, Inc., and was prepared in accordance with generally accepted
geotechnical engineering practices. This report is intended for specific application to the Stafford Crest Division
2 project and for the exclusive use of Stafford Homes, Group Four, Inc., and their authorized representatives. No
other warranty, expressed or implied, is made.
The analyses and recommendations presented in this report are based upon data obtained from the test pits
excavated on-site. Variations in soil conditions can occur, the nature and extent of which may not become
evident until construction. If variations appear evident, Terra Associates, Inc., should be requested to reevaluate
the recommendations in this report before proceeding with construction.
Page No. 10
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EXPLORATION LOCATION PLAN
;� ► ,.<� TERRA STAFFORD CREST DIVISION 2
y \, RENTON, WASHINGTON
1 ,
1
•. ASSOCIATES
- •Geotechnical Consultants Proj. No.3685-3 Date JUNE 1998 Figure 2 f
r- - i
12" MINIMUM WIDE
FREE—DRAINING GRAVEL
SLOPE TO DRAIN
12"
r
EXCAVATED SLOPE
_ - (SEE REPORT FOR
APPROPRIA)E.
INCLINATIONS)
' COMPACTED STRUCTURAL
- - BACKFILL
\^ 12" OVER THE PIPE
4" DIAMETER PVC 3"
BELOW THE PIPE
PERFORATED PIPE
NOT TO SCALE
RETAINING WALL DRAINAGE DETAIL
TERRA STAFFORD CREST DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No. 3685-3 Date JUNE 1998 1 Figure 3
Slope 2:1(H:V)
2 i✓
Swale for surface drainage control
0 0 0
o O O
000 �
000 ;
000 ;
Cn
1 O o 0 0 Competent undisturbed
X native soils
o 0 0
E N v
E O O �.
a� o ca 0 .o
a�
C 6 0 0 0
a�
00 E 0 0
U 0 0
C N 0
O O < Crushed rock filter j
0 O O O material, between 1.5
and 3 inch size with
0 0 0 less than 2% fines.
O 0
O O �
0 0 O
0 n�
r H i3
18 in. min. 4 in. min.
a gravel bedding
Firm undisturbed __/ I I
soil to be verified Ke wa ( 12 in.
by Soil Engineer Y y —� min. 4 in. minimum diameter
drain pipe surrounded by
clean washed pea—gavel
Keyway should be sloped or gravel.
down towards the face
being protected
K d
NOT TO SCALE-
ROCKERY CROSS-SECTION
."",:.. TERRA STAFFORD CREST DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No.3685-3 Date JUNE 1998 Figure 4
Slope 2:1(H:V) max.
- 2
1
Swale for surface drainage control
Mirofi 5XT Geogrid or egj'vclent
reinforcement approved by
Geotechnical Engineer.
(see reinforcing schedule be ow)
1.5' to 2.5'
L
0 1
T
E 1.5'
w
6
co
a Compacted Structural Fill
T
•�, 1.5'
Crushed rock filter 1.5'
material, between 2
and 4 inch size.
1.0'
i`
1 o In. min:
c
Grade at Rockery face
I
Firm undisturbed �3 in. min.
Keyway soil to be verified 12 in.
by Soil Engineer min. 4 in. minimum diameter
drain pipe surrounded by
gravel meeting WSDOT
Keyway should be sloped 9-03.12(2) specifications
down towards the face
being protected
GEOGRID REINFORCING SCHEDULE
Rockery Height No. of Grid Layers Grid Length (L)
4' 2 4'
6' 3 5'
8' 4 6.5'
NOT TO SCALE_
REINFORCED FILL/ROCKERY CROSS-SECTION
TERRA STAFFORD CREST DIVISION 2'
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No.3685-3 Date JUNE 1998 1 Figure 5
APPENDIX A
FIELD EXPLORATION AND LABORATORY TESTING
Stafford Crest Division 2
NE 36th Street and 109th Place NE
Renton,Washington
We performed our field exploration using a trackhoe and rubber-tired backhoe on September 2, 18, and 19, 1997.
We explored subsurface soil conditions at the site by excavating 37 test pits to a maximum depth of 20 feet
below existing grade. Of the 37 test pits, 14 of the test pits were found to lie within or near the boundary of
Division 2. The test pit locations we used for this report are shown on Figure 2. The test pit locations were
approximately determined by pacing and visual references from existing property lines and site features. The
Test Pit Logs are presented on Figures A-2 through A-8.
A geotechnical engineer from our firm conducted the field exploration and classified the. soil conditions
encountered, maintained a log of each test pit, obtained representative soil samples, and observed pertinent site
features. All soil samples were visually classified in accordance with the Unified Soil Classification System
described on Figure A-1.
Representative soil samples obtained from the test pits were placed in closed containers and taken to our
laboratory for further examination and testing. The moisture content of each sample was measured and is
reported on the Test Pit Logs. Grain size analyses were performed on selected samples, the results of which are
shown on Figures A-9 through A-13.
Project No.T-3685-3
MAJOR DIVISIONS LETTER TYPICAL DESCRIPTION
SYMBOL
Clean GW Well-graded gravels, gravel-sand mixtures, little or no
'GRAVELS Gravels fines.
JC (less than GP Poorly-graded gravels, gravel-sand mixtures, little or
O 5 N More than 5% fines) no fines.
Cn �'� 50% of coarse Silty gravels, gravel-sand-silt mixtures, non-plastic
.5 fraction is Gravels GM fines.
W m > larger than No.
•— 4 sieve with fines
Z E � GC Clayey gravels, gravel-sand-clay mixtures, plastic fines.
0
� Clean
0 SW Well-graded sands, gravelly sands, little or no fines.
o SANDS Sands
LU =Z (less than Poorly-graded sands or gravelly sands, little or no
:c C More than 5/a fines) S P fines.
< Q 50% of coarse
0 �'
o *' fraction is S M Silty sands, sand silt mixtures, non-plastic fines.
U smaller than Sands
No. 4 sieve With fines SC Clayey sands, sand-clay mixtures, plastic fines.
Inorganic silts, rock flour, clayey silts with slight
J o SILTS AND CLAYS M L plasticity.
OU) CaCL Inorganic clays of low to medium plasticity, (lean clay).
E o Liquid limit is less than 50% — —
W 0 Z N OL Organic silts and organic clays of low plasticity.
o CO
Q � �
< C `.a) MH Inorganic silts, elastic,
C0 _E am SILTS AND CLAYS —
W 0 CH Inorganic clays,of high plasticity, fat clays..
z 0 cn. Liquid limit is greater than 50% -- —
LL OH Organic clays of high plasticity.
HIGHLY ORGANIC SOILS FAT Peat.
DEFINITION OF TERMS AND SYMBOLS
w Standard Penetration 2" OUTSIDE DIAMETER SPLIT
Q Density Resistance in Blows/Foot I SPOON SAMPLER
0 Very loose 0-4 2.4" INSIDE DIAMETER RING SAMPLER
o Loose 4-10 J! OR SHELBY TUBE SAMPLER
Medium dense 10-30 I
z Dense 30-50 1 WATER LEVEL (DATE)
< Very dense >50
Tr TORVANE READINGS, tsf
Standard Penetration Pp PENETROMETER READING, tsf
J Consistency Resistance in Blows/Foot DD DRY DENSITY, pounds per cubic foot
U Very soft 0-2 LL LIQUID LIMIT, percent
o Soft 2-4
Medium stiff 4-8 PI PLASTIC INDEX
J
Stiff 8-16 N STANDARD PENETRATION, blows per foot
Very stiff 16-32
Hard >32
UNIFIED SOIL CLASSIFICATION SYSTEM
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3685-3 Date MAY 1998 Figure A-1
Test Pit No. TP-1
Logged by: ABK
Approximate Elev. 230'
Date: 9/2/97
Depth Moisture
(ft.} Soil Description Content
0 6 inches Forest Duff.
Brown SILTY SAND; fine, trace to few gravel and clay,
medium dense, moist. (SM)
5 Gray-brown SILTY SAND; fine, dense, moist. (SM) 14
Gray-brown SILTY SAND; fine, cemented, occasional gravel and cobbles,
10 thin interbeds of hard sandy silt, dense to very dense, moist. (SM)
Test pit terminated at 11 feet.
No groundwater encountered.
15
Test Pit No. TP-2
Logged by: ABK
Approximate Elev. 232'
Date: 9/2/97
Depth Moisture
(ft-) Soil Description Content
0 3 to 6 inches Forest Duff.
Light gray-brown SILTY SAND;fine, occasional boulder and scattered
gravel, some cementation, medium dense to dense, moist. (SM)
16
5
Less silty. 16
10
8
Gray-brown SILTY SAND WITH GRAVEL; fine, fine to coarse gravel, 10
very dense, moist. (SM)(Glacial till)
15 Test pit terminated at 14 feet.
No groundwater encountered.
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No. T-3685-3 1 Date MAY 1998 1 Figure A-2
Test Pit No. TP-3
Logged by: ABK
Approximate Elev. 262'
Date: 9/18/97
Depth Moisture
(ft.) Soil Description Content
o
0
Topsoil and organic silty sand; one large boulder, loose, moist.
Gray-brown SILTY SAND;fine, occasional seam of silt, medium
dense, (moist to) very moist. (SM)
5
Test pit terminated at 7 feet.
No groundwater encountered.
10
Test Pit No. TP-4
Logged by: ABK
Approximate Elev. 245'
Date: 9/19/97
Depth Moisture
(ft.) Soil Description Content(�io)
0 6 inches Topsoil over brown silty sand;fine, loose, moist.
9
5 Gray-brown SAND; fine, trace silt, cemented, occasional angular
boulder, occasional seams of cemented till-like silt,few roots in silt,
medium dense to dense, moist. (SM)
8
10
Test pit terminated at 10.5 feet.
No groundwater encountered.
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No. T-3685-3 Date MAY 1998 Figure A-3
Test Pit No. TP-5
Logged by: ABK
Approximate Elev. 235'
Date: 9/19/97
Depth Moisture
(ft.) Soil Description Content
0 6 inches Topsoil over organic silty sand;fine, loose, moist.
Brown SILTY SAND; fine, some cementation, medium dense, moist. (SM)
5
Brown SILTY SAND to SAND WITH SILT; fine, occasional to few
cobbles and boulders, occasional seams of cemented coarse sand and 11
silt, medium dense to dense;moist(to very moist). (SP/SM)
10 Test pit terminated at 10 feet.
No groundwater encountered.
Test Pit No. TP-6
Logged by: ABK
Approximate Elev. 252'
Date: 9/19/0-7
Depth Moisture
eft ) Soil Description
Content
0 6 inches Topsoil over organic silty sand;fine, loose, moist.
Brown to gray-brown SILTY SAND to SAND WITH SILT; fine, some
cementation, medium dense to dense, moist. (SM) 8
5
10 12
Test pit terminated at 10.5 feet.
No groundwater encountered.
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No. T-3685-3 Date MAY 19981 Figure A-4
x
Test Pit No. TP-7
Logged by: ABK
Approximate Elev. 228'
Date: 9/19/97
Depth Moisture
(ft.) Soil Description Content
0
Topsoil and organic silty sand; loose, moist.
13
Brown SILTY SAND; fine,some cementation, occasional cobbles
5 and angular boulders, seams of hard sandy silt, medium dense to
very dense, moist to very moist. (SM)
1 Test pit terminated at 9.5 feet.
No groundwater encountered.
Test Pit No. TP-8
Logged by: ABK
Approximate Elev. 225'
Date: 9/19/97
Depth Moisture
Content
(ft.) Soil Description Cont nt
0 Black organics and debris.
Gray-brown SANDY SILT, (to silty sand with clay); mottled, till-like,
occasional boulders and cobbles, fine, medium dense, moist. (MUSM) 15
5
Gray-brown SILTY SAND; fine,some cementation, interbedded with finer
siltier sand, dense, moist. (SM)
12
10 Test pit terminated at 9.5 feet.
No groundwater encountered.
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechniccl Consultants
Proj. No. T-3685-3 Date MAY 1998 Figure A-5
Test Pit No. TP-10
Logged by: ABK Approximate Elev. 227'
Date: 9/2/97
Depth Moisture
Content
(ft.) Soil Description Cont
Forest Duff
Brown SILTY SAND;fine, trace to little gravel, cemented and till-like,
trace to little clay, medium dense, moist. (SM)
5
Brown SILTY SAND WITH GRAVEL;fine, some clayey seams,
dense, moist to very moist. (SM)
10
22
Gray SILTY SAND; fine, some cementation,trace to little clay,
dense to very dense, wet. (SM)
15
17
Gray SILTY CLAYEY SAND with gravel;fine, cemented, few cobbles,thin
interbeds of sandy silt,very dense, very moist to wet. (SC-SM)(Till-like/Till)
20 Test pit terminated at 20 feet.
Light groundwater seepage encountered at 14 to 15 feet.
Test Pit No. TP-22
Logged by: ABK
Approximate Elev. 240'
Date: 9/18/97
Depth Moisture
(ft.) Soil Description Content
(%)
0
Forest Duff and organic silty sand; loose, moist.
Brown SILTY SAND;fine, some cementation, laminations of silt,
medium dense, moist to very moist. (SM)
5
Test pit terminated at 6 feet.
No groundwater encountered.
10
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechnicol Consultants Proj. No. T-3685-3 Date MAY 1998 Figure A-6
Test Pit No. TP-101
Logged by: RW
Approximate Elev.
Date: 6/11/98
Depth Moisture
(ft.) Soil Description Content
(0 to 6 inches) Sandy SILT with roots and organics, dark brown, moist,
medium stiff. (ML)
Silty SAND, brown, fine, medium dense, moist, blocky structure. (SM)
5 24.6
Silty SAND to SAND with silt, light brown, fine, medium dense. (SM-SP)
10
19.6
Test pit terminated at 12 feet.
No groundwater seepage.
15
Test Pit No. TP-102
Logged by: RW
Approximate Elev.
Dater 6/11/98
Depth Moisture
(ft.) Scil Description Content
(0 to 4 inches) Sandy SILT with roots, dark brown, moist, medium stiff. (/o)
(ML)
Silty SAND, brown,fine, medium dense. (SM)
5 29.s
Trace gravel at bottom. 22.4
10
Test pit terminated at 10 feet.
No groundwater seepage.
15
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
Geotechhical Consultants Proj. No. T-3685-31Date JUNE 1998 Figure A-7
4
Test Pit No. TP-103
Logged by: RW
Approximate Elev.
Date: 6/11/98
Depth Moisture
(ft.) Soil Description Content
(0 to 4 inches) Sandy SILT with grass roots, dark brown, moist, loose.
(ML)
5 Silty SAND with gravel, brown, moist, medium dense to very dense. (SM) 20.4
10
More gravel,very dense.
12.7
Test pit terminated at 12 feet.
No groundwater seepage.
15
Test Pit No. TP-104
Logged by: RU!
Approximate Elev.
Date: 6/11/98
Depth Moisture
(ft.) Soil Description Content
(0 to 4 inches) Sandy SILT with grass roots, dark brown, moist, stiff. (ML)
5 Silty SAND, brown, fine, moist to wet, dense. (SM) 23.0
1 27.7
Test pit terminated at 11 feet.
No groundwater seepage.
15
TEST PIT LOGS
TERRA STAFFORD CREST, DIVISION 2
ASSOCIATES RENTON, WASHINGTON
L Geotechnical Consultants
Proj. No. T-3685-3 ;Date JUNE 1998i Figure A
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
�Ln� 00 0 0 0 0 0 N O) A LAN N? -P W fJ CD ?• O O S O O O 01 �. W N -�OO Ol
100 0
4
90
10
c�
0
D—I 80
(n M 20
(n�U m M
O;7 � 70 30 n
ai n D Z -ZI
D Tl 60 40
O
D
50 50 rV)
40 — 60 CO
m _
30 70 rn
o - _
CF) to 20 80
00
Cn
D —
1 �Tl
m
(ACD
D 10 90
o O
=mq-
.+ Z
CD V OW tN 00 O) N CO M .A W N 100
C- TJ fV oo S S o o �' o o -' oo o) :s- i4 iv CO Qo) o� o CA nog o 0 0 0 0 o g
m � IT' GRAIN SIZE IN MILLIMETERS CO C" � o 0
= D
z ZD COBBLES COARSE FINE COARSE MEDIUM FINE FINES
�� �
I GRAVE SAND
Oz O Cn
Z Key Test Pit Depth USCS Description Moisture
CDN Number (ft.) Content LL PL
n
• TP-2 4.0 SM silty SAND with gravel
0 TP-2 9.0 SM silty SAND
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
f:7-77r"T7 N .A rn n cNi
O O b O b OOf 4• 4r fJ -V+
100 v 0
1
90 - -
c� 10
c�
o_
`D D 80
s (n M _ 20 -0(n�7 m �
o O;U 70 30 m
c C)D Z
o D m 60 40 n
—I z o
D
� 50 50 vv))
40 60 CO
v m
= 30 70 m
v) 20 80 -
c�n D
I �TIC
m
0
Z o Z
O 10 — _ 90
z � 00
co C7 0 p pp po
m D>� N O S S O O O O O COOD O) P W N -•OD b :P 4A N OOi O O O 0 0 O 0 0 O d
� m GRAIN SIZE IN MILLIMETERS f 00 a) � W N --
= D
Z o COBBLES COARSE FINECOARSE MEDIUM FINE CO I - GRAVEL FINES
00 --<
i
O Cf)
Z Key Test Pit Depth USCS Description Moisture LL PL
N
Number (ft.) Content (�)
D
! • TP-4 8.0 SP—SW SAND
0
0 TP-5 6.0 SM silty SAND
� M
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
_ N. O O O �7 n n
iJ G� V UO O O O O O O O O O O_
1 OO N C n (A i) IJ p � 4P Cb N 00 is {a O O � O O O Cn -P C 4 N OD rn �► Cd N
4. 0
'�. 90 —
m
_ 10
0
CD —I e0
�M 20 M
� 0� C 70 30 m
v=i ` J D Z Z
60 40
z O
D
50 50 m
Cl) �7
40 — - 60 W
= 30 —— —— — — 70 m
o - _
C4 20 -{
� D 80
w D 10 - _ - -- - -- 90
o OC) Z -
co Z C7 0
100
:Z7 IV o 0 0 0 o g o o°D Q' C'' �' bo 6) � iA K3
D O O 0 0 O O
C ( i CD O C. O CD O O O O
iz >C GRAIN SIZE IN MILLIMETERS CO CM -- C-4 N
= D
CO Z� D COBBLES COARSE FINECOARSE MEDIUFA FINE FINES
00 <E
OZO �
Z Test Pit Depth Key USCS Description Moisture
CDN Number (f0 Content (%) LL PL
n • TP-10 16.5 ML sandy SILT
I
0 TP-101 5.0 SM silty SAND with gravel
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
N (n O CO 0 0 0 O O O CD CD CD O
1 OON 07 P W N N P. N oo ? O O O O O O O) 4- CAN -.COCn 41 W N
0
y t. 0
G') r 9 10
O_
D 80
n —
U)M 20
o M fTl
l �TJ
o O� n 70 30 m
Nit
c C)D
D -,1 60 40 t7
(TI M 50 50 C/)
(j) m
40 60 M
M
= 30 — 70 m
o � �
� 20 80
Cn D
-9 G7 —
O Q 710
10 90
0
CD z 0 100
�7 fV O O O O O W N f 00 O" a'' W N
O O O O O O J 'P W N O O O D O 0 0 O O O O
m >�`�' GRAIN SIZE IN MILLIMETERS N m M C o o S
= D
Z < D COBBLES COARSE FINE COARSE MEDIUM FINE FINES
-t Cn
n OZ O �
z Test Pit Depth
Key USCS Description Moisture
CDN Number (ft.) Content (%) LL PL
n
! • TP-101 12.0 SM silty SAND
N
0 TP-103 5.0 SM silty SAND with gravel
�► M
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
:74N O W N N\ \\\\
�► .A•pO N CO {a .p p g C) O 00 0) O O O O S CD O O O O
100 4` v+ N 01 P. (A N
0
90
CD 10
0
CD
80
C/)M 20
o (�� r� r�,
0�7 70 _ 30
m
a, ` J D Z Z
o D 60 40 n
-I z O
rn M 50 50 cry)
m
CO
40
60 C10
m
30 -
o �
CA _
00 20 80
cn D
(A o Q z 10 _ 90
0
Z
C7 0pp .pp ((,.�� 100
X N d O S O d 0 Np OD O) A W N 00 O) �► W N J 000 rn O O O O O O O O
m � �' GRAIN SIZE IN MILLIMETERS p p p p p o
-CO Q) CA W N
= D
z o D COBDLES COARSE FINE COARSE MEDIUM FINE
0 Q c FINES
—I
n OZ O (n
Z Key Test Pit Depth USCS Moisture
CD N Number (ft.) Description Content N LL PL
n
! • TP-103 12.0 SM silty SAND with gravel
w