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14039 Night Song Ct Report Of Compaction For Proposed Addition Soil Testing I Fill Control Geotechnical Investigations fST. 1973 -ENGINEERING, INC.- Client: Mr. Randy Tan February 8, 2016 c/o Hamilton Do Job No. 15-050 140.39 Night Song Ct. Chino Hills, CA 91709 Subject: REPORT OF COMPACTION Proposed Addition 14039 Night Song Ct. Chino Hills, CA 91710 Mr. Do: Thank you for the opportunity for Duco Engineering, Inc. to provide geotechnical services for your project. The following presents a synopsis of grading operations and report of compaction for the development of the proposed garage addition with second story living space at 14039 Night Song Court, in the City of Chino Hills, California. Reference material included the previous site-specific geotechnical update prepared by this firm, as well as the provided site plan (a reduced copy included herewith). Based on the supervision, testing, and analysis, it is the opinion of this firm that the grading work undertaken for the proposed garage addition is in general conformance with the recommendations made in our prior report, as well as pertinent code requirements per the California Building Code and municipal regulations. Furthermore, it is our opinion that, as reported herein, fill soils placed have been compacted to in excess of 90% of the maximum dry density, Should you have any questions with regard to this report, please contact this office. Respectfully submitted, DUCO ENGINEERING, INC. Approved by: QR0FESs 6•,,,% e G- s7-/z74( \\ ns. jI 44 IVO.0E .9 jos ±tL '30'2017j. ' , 1-r.- :G r Dbniel Dufrenne Frank C. Stillman '5, 00 vz7 Project Engineer GE No. 805 1 �`cft t31:� 14175 Telephone Ave., Ste.K Chino,California 91710 I 909.594.7414 I 800.650.4910 I office@ducoengineering.com Duco Engineering, Inc. Job No. 15-050 Page 2 OVERVIEW In accordance with your request, this firm has performed geotechnical supervision of grading operations for the proposed garage addition with living space above, between December 2, 2015 and February 5, 2016. Grading work undertaken for the proposed development consisted of overexcavation and recompaction of subgrade soils in areas of proposed construction to provide a sound, uniform bearing surface in conformance with recommendations previously made by this firm. Existing soils were removed to approved ground (previously compacted fill), 2.0 feet below existing grade, prior to placing compacted fill soils as per recommendations in prior reporting. Structural fill areas were laterally overexcavated 1:1 the fill depth outside the proposed foundation footprint in every direction, with a minimum lateral overexcavation limit of 3 feet outside the building area where possible. Prior to backfill, exposed excavation bottoms were inspected and approved by a representative of this firm. Backfill soils were then tested (at a minimum) for each subsequent 2 feet of placed material to ensure compaction in excess of 90% of the maximum density, up to finished grade, per the referenced plan. Finished grade was assumed at eight (8) inches below the existing garage floor at the door. A plan showing extents and depths of fill and test locations is attached herein. Grading After inspection and approval by a member of this firm, the excavation bottom was moistened, then scarified to an approximated depth of 6 inches and compacted to accommodate the placement of additional fill. Fill soils were spread in 6 to 8-inch-thick loose lifts, watered or dried back as necessary, and compacted to the minimum specified requirement. A water hose and rubber-tired grading equipment were used to add moisture to and compact the backfilled soils. Testing Field density tests were performed during the course of grading in accordance with ASTM test method D1556, using a standard sand cone density testing apparatus. Tests were taken for every 2 feet in thickness and/or 500 cubic feet of placed, compacted fill. The results of these tests are attached as a part of this report. Maximum density and optimum moisture were determined in accordance with ASTM test method D1557, the modified proctor method for the determination of the maximum density curve. The results of maximum density determinations are as follows. Table 1:Maximum density and optimum moisture for graded material Soil Type Max.Dry Den. (PCF) Opt.Moist. A—Silty Clay w/Sand 116.1 15.8% Duco Engineering, Inc. Job No. 15-050 Page 3 CONCLUSION AND RECOMMENDATIONS Based on the results of the field density tests, as reported herein, it is the opinion of this firm that the backfill soils as tested have been compacted to in excess of the minimum specified requirement of 90% of the maximum dry density. Furthermore, it is our opinion that grading operations were conducted, and structural fills constructed, in accordance with standard geotechnical practices and procedures. Recommended Design Values: With regards to foundation design for bearing and lateral loading, this firm offers the following recommendations for conventional spread and continuous footings and corresponding concrete slabs: Table 2: Recommended shallow foundation design values Soil Resistance Allowable Bearing Capacity(qa): 2500 psf Allowable Passive Resistance(pp): 300 psf/ft Friction Coefficient(concrete on fill): 0.35 Continuous Footings Minimum Width(B) One Story: 15 in. Two Story: 15 in. Minimum Footing Depth(Df): 24 in. Square Footings Minimum Side Length(B): 18 in. Minimum Footing Depth(Df): 18 in. Expansive Soils Expansion Index (CBC): 78 (A),—MODERATE Minimum Foundation Reinforcement: Two(2) #4 bar in ftg.top and bottom Minimum Slab Thickness: Full 4 in. Minimum Slab Reinforcement: #4 bar 18 in. c/c each way Required Slab Underlayment: 10-mil visqueen centered 4 in. wash.conc.sand Subgrade soils shall be moistened to a minimum to 120% of optimum moisture—regardless of in- place moisture content—prior to pouring concrete slabs. Additional reinforcement may be necessary at the discretion of the structural engineer. A grade beam shall be placed across any garage type door opening. Retaining walls are not proposed; see preliminary geotechnical evaluation report for guidelines. Duco Engineering, Inc. Job No. 15-050 Page 4 Drainage All site drainage should be collected and transferred to the street or approved storm water drainage structure. No drainage should pond against any foundation or retaining wall. Drainage should not be allowed to flow uncontrolled over any slope or pond at the top of any slope. Any planned area drains should be recessed below grade to allow the free flow of water into the drain inlet. Flatwork and concrete walks should be at an elevation such that they will not obstruct the flow of surface water. Proper drainage should be maintained at all times. Closure All work performed and recommendations made by this firm are considered to be in conformance with the governing codes, laws, and sound engineering practice, and applies to the above referenced construction only. No other warranty, approval, or certification is expressed or implied for any additional work not described in this report performed by this firm or others, including work done at a later date. Should any significant changes be made to this proposed project at a later date, this firm should be notified; additional grading and/or geotechnical design and oversight may be necessary to accommodate such changes. Any inquiry regarding the contents of this report or work undertaken by this firm may be directed to this office. A 1 ` / __ ��.., '.9J ,I.r I...Npf... t•i +/'ØV//7 d' _yJ jFfea' -. A / 00 3 C L 4]r /JV 1�. J pT aff Y" >,.:'''Er a'J. ty L '.Jf'' ,®'M1" /' / J ;dl'1 V'V' 6 //// -0' /0 �pe 1 • , / r ,y�` P r� J d,/,„/ JJ'ef /..0''� ' ...J'J tiJffJi ddd"' ✓ 0 t E 4 �s� �J I , � ,� 1 , 1' " 0 • PROJECT: , SHEET TITLE: DUCO Job No.15 050 PROPOSED GARAGE LIMITS 0� 1"=10' 14039 Night Song Court COMPACTION LIMITS OF -ENGINEERING, .INC - , Chino Hills, CA 91 09 FIG. 1 Duco Engineering, Inc. Field Density Tests Lot Elevations Dry Den. Soil Date No. Natural Fin. Gr. Test % Moist. P.C.F. Type % Comp. 1 2/4/16 -0.5'FG 15.2 106.3 A 91.6% 2 2/5/16 FG 14.7 105.8 A 91.1% 3 2/5/16 FG 14.9 106.1 A 91.4% Job No. 15-050 14039 Night Song Ct. Chino Hills, CA