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HomeMy WebLinkAboutR-436048DESIGN NOTES Reference: 1. Barghausen Consulting Engineers, LLC, Detailed Grading Plan, Job No. 22298, dated March 13, 2025 2. Earth Solutions NW, LLC, Geotechnical Engineering Study, updated July 3, 2023 The following design assumptions were used: • Internal angle of friction for reinforced soil = 32 degrees (general design) • Unit weight of reinforced soil = 125 pcf (general design) • Maximum total wall height = 8.00 feet • Batter of wall = 1 H : 10V • Site -modified peak ground acceleration = 0.719 g (per 2021 IBC; Site Class C) • Surcharges (Where Applicable) = 3,000-plf Footing Strip Load 2H:1 V Top Slope TECHNICAL SPECIFICATIONS FOR MECHANICALLY STABILIZED LOCK + LOAD RETAINING WALLS GENERAL A. The work involves the supply and installation of mechanically stabilized earth (MSE) retaining walls. The Concrete Panels and Counterforts will consist of Lock + Load Stone. Counterforts and Geogrid are the types of soil reinforcement. The work will include, but is not limited to: • excavation to the grades shown on the civil drawings • supply and installation of geogrid reinforcement • supply and installation of drainage fill and piping • supply and installation of segmental Lock + Load Stones • supply and installation of retained and reinforced soil fill B. The walls shall be installed on undisturbed Native Soils or Structural Fill, as appropriate. MATERIALS A. Concrete Panels and Counterforts are locked together to form a "Stone". The retaining walls have been designed on the basis of Lock + Load Retaining Wall "Stones". "Stones" are to be purchased from a licensed Lock + Load manufacturer. The Lock + Load trademark on each pallet identifies Lock + Load products. B. Information on the purchase of Lock + Load products can be obtained through: Pacific LOCK + LOAD, Inc. Telephone: (503) 682-2868 Website: www.pacificlocknload.com C. Geogrid: Structural geogrid reinforcement shall consist of Miragrid 5XT or an alternative approved by the Geotechnical Engineer. D. Drainage Fill: Drainage Fill placed around and above the perforated drainage pipe shall consist of round or angular 3/4-inch to 1-inch clean rock. E. Face Gravel: 3/4-inch to 1-inch clean crushed rock or approved equivalent by the Geotechnical Engineer. F. Reinforced and Retained Soil: Suitable granular material approved by the Geotechnical Engineer. G. Leveling Course: The Leveling Course shall consist of angular, crushed aggregate with maximum size of 3/4 inch. The Leveling Course Fill may be single size or may be well graded containing a maximum of 5% passing the No. 200 sieve. EXECUTION A. Contractor shall excavate to the lines and grades shown on the construction drawings. The Geotechnical Engineer should observe the excavation prior to the placement of the leveling material or fill soils. B. Over -excavation of deleterious soils or rock shall be replaced with material meeting the specifications described in Materials Section "F" above. The material shall be compacted to 95% of ASTM D1557 (Modified Proctor) and shall be at (or slightly above) the optimum moisture content. C. The first course of concrete Lock + Load "Stones" shall be placed on the Leveling Course, and the alignment and level shall be checked. D. "Stones" shall be placed with the top of the panel level and parallel to the wall face. The Counterfort Base shall be installed horizontal and perpendicular to the face of the retaining wall. E. Geogrid shall be oriented with the highest -strength axis perpendicular to the wall alignment. F. Geogrid reinforcement shall be placed at the levels and to the lengths shown on the drawings and shall begin at the back of the Lock + Load Panels. G. The geogrid shall be laid horizontally in the direction perpendicular to the face of the retaining wall. The geogrid shall be pulled taut, free of wrinkles, and anchored prior to backfill placement on the geogrid. H. The geogrid reinforcement shall be continuous throughout respective embedment lengths. Spliced connections between shorter pieces of geogrid are not permitted. I. The drainage pipe discharge points shall be connected to an approved system. J. Reinforced and Retained Backfill shall be placed, spread, and compacted in such a manner that minimizes the development of slack in the geogrid. K. Reinforced and Retained Backfill shall be placed and compacted in lifts not to exceed 8 inches where hand -compaction equipment is used and not more than 12 inches where heavy compaction equipment is used. Compaction should occur over the tail of the Counterfort prior to areas away from the retaining wall. Hand -operated vibratory plate compaction equipment (700 lb. to 1,000 lb.) shall be used to compact the face gravel at wall face. L. Reinforced and Retained Backfill shall be compacted to 95% of the maximum dry density as determined by ASTM D1557 (Modified Proctor) or equivalent. The moisture content of the backfill material prior to and during compaction shall be uniformly distributed throughout each layer and shall be at (or slightly above) the optimum moisture content. M. Hand -operated compaction equipment (700 lb. to 1,000 lb.) shall be used within 26 inches of the front face of the concrete facing. N. Tracked construction equipment shall not be operated directly upon the geogrid reinforcement. A minimum fill thickness of 6 inches is required prior to operation of tracked vehicles over the geogrid. O. Rubber -tired equipment may pass over the geogrid reinforcement at speeds less than 5 mph. Sudden braking and sharp turning shall be avoided. P. At the end of each day of operation, the contractor shall slope the last lift of reinforced backfill away from the wall units to direct runoff away from the wall face. The contractor shall not allow surface runoff from adjacent areas to enter the wall construction site. GEOTECHNICAL OBSERVATIONS & TESTING A. The Geotechnical Engineer shall be retained to provide observation and testing services during Lock + Load retaining wall construction. The Geotechnical Engineer shall be contacted, at least 48 hours prior to the start of wall construction and related grading activities, to observe Lock + Load wall installation on a full-time basis. B. Observations by the Geotechnical Engineer (or their representative) do not relieve the contractor of their responsibility to comply with the contract documents, including the notes, details, and specifications provided on these sheets. C. At a minimum, the Geotechnical Engineer shall be retained to observe and/or test the following: erosion control; excavation activities; subsurface drainage installation; soil bearing and subgrade/keyway competency; Lock + Load panel installation and wall batter; structural fill placement and compaction testing; and verification of proper geogrid strengths, lengths, and orientation. 6'-0" (Max.) Wall Height H = 8' (Max.) Fence 0,< (By Others) 1 10 pQ 4 a p4 v4va ° D4v�D -o 174 D 4 °a � 1 017 �Q a 4✓ d °°D a °°D Top Slope 2H:1V (Max.) 2 1� Geogrid Reinforcement (See Geogrid Schedule) Geogrid Laler 2 (etc.) a 4 Reinforced NOTES 1. Wall alignment and heights to be established by Contractor / Surveyor. 2. Geotechnical Engineer to confirm Keyway stability, support characteristics, and overall stability prior to construction. GEOGRID SCHEDULE (WEST OF TRACT A) M17wmmmiimm M==EEM ===OEM OMMEEM GEOGRID: A = Miragrid 5XT Retained Soil °oQoae4 p yx Soil ° ° D ° D 7 2.67' o a Drainage Blanket a ° o Qoa 4 (typ.) ° ° ° (As Necessary per o 17 Geotechnical Engineer) vo . Geogrid Layer 1 ° D G Level Toe Slope a ° Geogrid Length L�4ap° °oar D 4 NOTE: Geotechnical Engineer shall oa o Qoa °4 4 Q18" of Well -Compacted o o ° evaluate the need for Supplementary °a °4 o a {; Face Gravel{ ao 4a 4Drainage g Draina e behind the Reinforcement 44 4a QQQf{f�4 �Qo{�4}}Q o��4{4 oQao Qova4 / Zone during Construction. v4 v a °4Da d D a 4Da D ° 4B4 v/ aD ° v OJ e Q aif?�i}i4i{}I{f 4° _} ff° Mirafi 140N NOTE: Wall Toe Backfill must be placed 12" (Min.) =III —III —III Filter Fabric duringor immediate) after wall construction. __ = 4" Perforated Drainpipe y On -Grade (If Necessary per 4" - 6" Leveling Course ( ) Geotechnical Engineer) Surround with Clean Rock Client Ichijo USA Co., Ltd. Proj. No. 8888.02 Date 03/21/2025 Designed KDH Drawn MRS Checked KDH Approved KDH No. Date Revision MSE CONDITION WEST OF TRACT NOT - TO - SCALE EARTH SOLUTIONS 1Cd Geotechnical Engineering Environmental Services Earthwork Observation & Testing CESCL & Stormwater Services REDMOND 425-449-4704 PASCO 509-905-0275 SILVERDALE 360-722-5081 esnw.com 6'-0" (Max.) Wall Height H = 6.67' (Max.) Level Toe Slope Fence — (By Others) 1 10 GEOGRID • # of Panels Wall Height (feet) Geogrid Length (feet) Layers 1 2 3 3 4.00 6.00 A - - 4 5.33 7.00 A A - 5 6.67 7.00 A A - GEOGRID: A = Miragrid 5XT Level Top Slope 5' (Min.) Footing Setback I I I a v4D dD° ` Geogrid Reinforcement (See Geogrid Schedule) = III Retained 74 D Geogrid Layer 2 Soil 4 4 d v D°°� Reinforced ao 4 Q Qp 4 Q Q p 2 67' Soil Drainage Blanket o a ° 41 7, a (typ.) ° ° a I I (As Necessary per D4 q Geotechnical Engineer) a° °'- a vo o ° vo . Geogrid Layer 1 a o apM= o a ° ° a Geogrid Length Lb4 v°J 4 D G F NOTE: Geotechnical Engineer shall 18" of Well -Compacted ° evaluate the need for Supplementar a D a ooao oa4o''o a a a ate- G � Y ° °, v4 o a °dfff Face Gravel ea 17 Drainage behind the Reinforcement 4a a° 4'a'°fry°off°44 Q Q{v4{Q Qva}° Qva Zone during Construction. v ° v4 D a 4Da 4Da 4Da 4Da 4 v . Q D 4 p C1 a �a}}{{{{{{{{{{{{{{{ }l} { { s Mirafi 140N NOTE: Wall Toe Backfill must be placed 12" (Min.) =III —III —III Filter Fabric during or immediately after wall construction. ? _ = 4" Perforated Drainpipe (If Necessary per 4" - 6" Leveling Course (On -Grade) Geotechnical Engineer) Surround with Clean Rock MSE CONDITION BETWEEN LOTS 18 & 16117 NOT - TO - SCALE Lock + Load Wall Designs and Notes HARMONY RIDGE Renton, Washington DEVELOPMENT ENGINEERING HBray 02/10/2026 ='D R-436048 Sheet No. w2