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Home My WebLink AboutCT 05-03; LINCOLN & OAK MIXED USE; GEOTECHNICAL OBSERVATION & COMPACTION TEST;I H / f---- V/\ \\-J I ENGINEERING AND ENVIRONMENTAL 4373 Viewridge Avenue Suite B San Diego, CA 92123 858.292.7575 I Fax 858.292.7570 www.usanova.com Mr. Russell Bennett January 24, 2012 Lincoln & Oak Mixed Use Project No. 10125-1011071.000 I Carlsbad, California Subject: Summary of Geotechnical Observation and Compaction Test Results I Lincoln & Oak Mixed Use 3112 Lincoln Street Carlsbad, California I Permit No. GR110011, Drawing No. 451-7/7A Gentlemen: In accordance with your request, NOVA Engineering and Environmental, LLC's (NOVA) has provided geotechnical observation and compaction testing services during site grading for the Lincoln & Oak Mixed Use project located at 3112 Lincoln Street in the City of Carlsbad, California. The scope of our services reported herein includes the following: Observation of earthwork operations Compaction testing of fill during grading I • Laboratory testing of fill materials to evaluate relative compaction I . Preparation of a Field Density Test Location Plan Preparation of this final report I PROJECT DESCRIPTION The Lincoln & Oak Mixed Use project consists of a two- to three-story retail and residential building development. The project site is bounded by Lincoln Street to the west, Oak Avenue to the north I and existing driveways for residential and retail buildings to the east and south, respectively. GEOLOGIC CONDITIONS The geologic units encountered during grading at the site included artificial fill and Terrace Deposit materials. As encountered, the fill materials consisted of brown silty sand and the Terrace Deposits I consisted of reddish brown, friable silty sandstone. In addition, a vertical pit with an approximate diameter of five feet and an empty brick-lined tank were encountered during grading at the south- Offering services nationwide: Environmental Consulting and Remediation - Geotechnical Engineering - Construction Materials Testing and Inspection Services Facility Engineering - Building Envelope Consulting - Loss Prevention - Municipal Support/Outsourcing Code Compliance - Construction Defect Mitigation TM - Private Provider TM Lincoln & Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 west area of the project. Undocumented fill and debris in this area were completely removed and replaced with two-sack sand/cement slurry. SUMMARY OF EARTHWORK OPERATIONS AND SHORING INSTALLATION Based on our observations, the potentially compressible soils consisting of undocumented fills were completely removed during grading. Preparation of the soils exposed at the bottom of the remov- als for fill placement consisted of scarifying to a depth of 6 inches, moisture conditioning, and com- compacting the soils to 95 percent relative compaction as evaluated by ASTM D 1557. Stockpiled fill soils derived from on-site excavations were processed, moisture conditioned, and placed in lifts ap- proximately 6 to 8 inches in loose thickness and compacted. The contractor used dozers to spread the materials and a loader and vibratory roller to compact the soils placed as fill. Test results indi- cate the areas tested were compacted to a relative compaction of 95 percent as evaluated by ASTM D 1557. The approximate locations of the field density tests are shown on the attached Figure 1, Field Density Test Location Plan. Observation and testing services performed during grading as re- ported herein were provided by NOVA during the period of November 10 through November 22, 2011. LABORATORY TESTING Laboratory determination of maximum dry density and optimum moisture content for representative samples of on-site soils placed as compacted fill were performed in accordance with I ASTM Test Method D 1557. Laboratory and field testing results developed during grading are sum- marized in the text of this report and in Tables I and II of this report. The expansive potential of the I fill materials was evaluated in general accordance with ASTM D4829 and the results are presented in Table 1. TABLE 1 I LABORATORY EXPANSION INDEX TEST RESULTS I Sample Location Building 2 - Unit 2 Expansion Index Expansion Potential 3 Very Low Corrosivity testing was performed on a representative sample of the on-site soils to evaluate pH I and electrical resistivity, as well as soluble chloride and sulfate contents. The pH and electrical resis- tivity tests were performed in accordance with California Test Method 643 and the sulfate and I chloride tests were performed in accordance with California Test Methods 417 and 422, respective- ly. These laboratory test results are presented in Table 2. I S 2 Lincoln & Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 TABLE 2 LABORATORY CORROSIVITY TEST RESULTS Sample Location pH Resistivity Water-Soluble Water-Soluble (ohm-cm) Sulfate (ppm) Chloride (ppm) Building 2 - Unit 2 7.2 3600 18 43 Caltrans Corrosion Guidelines (2003) identify a site as being corrosive if the tested soils have more than 500 ppm chlorides, more than 2,000 ppm sulfates, or a pH of 5.5 or less. According to the results of our laboratory testing, the site is not considered to have a corrosive potential based on Caltrans criteria. A corrosion engineer may be consulted for additional recommendations. CONCLUSIONS AND RECOMMENDATIONS Cuts and fills covered by this report have been completed under NOVA's testing and observation. NOVA certifies that the soil engineering and engineering geologic aspects of the grading are in com- pliance with the project geotechnical reports (Geosoils, 2004, 2010) and grading plans, Drawing No. 451-7A prepared by Conway & Associates, Inc. (2011). It is anticipated that building foundations will be underlain by compacted fill, formational materials, or sand-cement slurry extending to formational materials. Continuous footings should have mini- mum width and depth of 12 inches and isolated footings should have minimum width and depth of 24 inches. Shallow footings may be designed using an allowable bearing capacity of 1,500 pounds per square foot (psf) with an increase of 300 psf per additional foot of depth to a maximum value of 2,500 psf. These allowable bearing capacities may be increased by one-third when considering loads of short duration such as wind or seismic forces. Footings should be reinforced in accordance with the recommendations of the project structural engineer LIMITATIONS This report presents information and data relative to the grading of the subject site. Representa- tive(s) of this firm conducted periodic tests and made observations during the progress of the construction in an effort to evaluate whether compliance with the project drawings, specifications and applicable Building Code was being obtained. The presence of our personnel during the work progress did not involve any direct supervision of the contractor or his work forces. Professional and technical advice and suggestions were provided to the owner and/or his designated repre- sentative based upon our observations. Completed work under the purview of this report is considered suitable and adequate for the intended use. 3 Lincoln & Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 Conditions of the referenced reports remain applicable unless specifically superseded herein. Should you have any questions, please do not hesitate to contact the undersigned at (858) 292- 7575, or e-mail at abernal@usanova.com. Respectfully submitted, NOVA Engineering and Environmental 2J No. 2715 Exp.aA49~ 9/30/13 Andres Bernal, E2L15 4*0 Principal Geotechnical &4f4/44"A ryan iller- icks, CEG 1323 Engineering Geologist AL Distribution: (2) Addressee (2) City of Carlsbad, Attn: Mr. Jay Jordan Attachments: Figure 1- Field Density Test Plan Table I -Summary of Density Curves Table II - Summary of Compaction Test Results 7c U 5/2OtA fBRYAN Mll.LER-HtCKS\ I NO. 13 I CERIIFIED ENGINEERING / 401: r, AVN~,O~~ No. 2715 Exp.913Q16 4 IN Lincoln & Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 REFERENCES Conway & Associates, Inc., 2011, Grading Plans for Lincoln & Oak Mixed Use, Drawing No. 451-7A. GeoSoils, 2004, Preliminary Geotechnical Evaluation, 3112 Lincoln Street, Carlsbad, San Diego County, California, dated: January 14 (their W.O. 4147-Al-SC). GeoSoils, 2010, Geotechnical Update for Structural Design, 3112 Lincoln Street, San Diego County, California, dated: September 27 (their W.O. 4147-Al-SC). GeoSoils, 2011, Geotechnical Review of Grading Plans, Lincoln & Oak Mixed Use, 3112 Lincoln Street, dated: February 11 (their W.O. 4147-A2-SC). NOVA Engineering and Environmental, 2011a, Assumption of Geotechnical Engineer of Record, Lincoln & Oak Mixed Use, Permit No. 110011, dated: October 27. NOVA Engineering and Environmental, 2011b, Additional Grading and Foundation Recommendations, Lincoln & Oak Mixed Use, Carlsbad, California, dated: November 4. 5 PH OAK AVENUE ENTRANCE / .. - / L : All --4 -- - "- .-goo a () 49 51 I47.5I,. • 8 149 I t I 20 2R -T, ,/ 1 5 3 , ..'''G-6 ' " ' " 2 CA GROUND BD 1 50 2C !34° c'iI k GAI it 'c 24 4 9.6CA AA'4.i . 12 2 6 ____ • A 48 5I , I 49 AR R 39 EjjjA ..) I _____ I " 49 4G 25 I37I PAAKINÔ GA9AGE . • Aft 1 47 ' LJ 4 40 Afc 61A T 14631 l46.6I 0 iL. , 4Qt)_. RO I' / Q_3' -/ G-4' '- I.3l38 IARjZ7 :. AC . 2CAR ''r °f 1481 ...... 1 I 2 • GRON LEVEL LD 2 J J • I! • >A 30 27 .13 14 ,. -29 - I 48 I I _4 .J465I 0)7.5 -- : LEGEND 10' 5' 0 10, 20' Afc Artificial Fill - Compacted SCALE 1" = 20' Qt Terrace Deposits (bracketed where buried) 41 Approximate Location of Field Density Test REFERENCE: CONWAY & ASSOCIATES, 2011, GRADING PLANS FOR LINCOLN AND OAK MIXED USE. 147.51 Approximate Elevation of Removal Bottom (feet, MSL) g. . . Approximate Location of Slurry Backfill - - - Approximate Limits of Grading NOTE: ALL DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. Lincoln and Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 TABLE I Summary of Density Curves Laboratory Maximum Density ASTM:D 1557 (All Soil Types) Optimum Maximum Moisture Dry Density Soil Type & Description (% dry wt.) (lbs./cu.ft.) A Brown Silty Sand . 8.0 133.5 B Reddish Brown Silty Sand 7.0 137.0 LEGEND Test Location - Indicated by Building Pad or Driveway area. Elevation - Indicated by approximate Elevation (feet, msl), or Finish Grade (FG) level. R,R1... - Indicates retest of previous compaction test failure, following moisture conditioning and/or recompactio TEST TYPE N - Indicates test by Nuclear Gauge (per ASTM:D 6398). NOVA ENGINEERING AND ENVIRONMENTAL Lincoln and Oak Mixed Use January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 TABLE II Summary of Compaction Test Results Test Depth/ Moisture Unit Dry Density Rel. Soil Test Proj. Date Number Test Location Elevation Opt. Field Max. Field Comp. Type Type Spec. Pass/Fail 11/10/11 1 Building Pad 1 - West 48.0 8.0 7.0 133.5 126.4 95 A N 95 Pass 2 Building Pad 1 - West 48.0 8.0 7.0 133.5 127.1 95 A N 95 Pass 3 Building Pad 1 - Center 48.0 8.0 7.3 133.5 126.3 95 A N 95 Pass 4 Building Pad 1- Center 48.0 8.0 7.4 133.5 126.5 95 A N 95 Pass 11/14/11 5 Building Pad 1 - Center 49.0 8.0 9.0 133.5 127.7 96 A N 95 Pass 6 Building Pad 1 - Center 49.0 8.0 9.7 133.5 126.5 95 A N 95 Pass 7 Building Pad 1 - West 49.5 8.0 9.4 133.5 126.9 95 A N 95 Pass 8 Building Pad 1 - Center 49.5 8.0 8.7 133.5 127.2 95 A N 95 Pass 9 Building Pad 2- G1 47.0 8.0 8.8 133.5 127.0 95 A N 95 Pass 11/15/11 10 Building Pad 1 - East 49.5 8.0 8.1 133.5 126.7 95 A N 95 Pass 11 Building Pad 1 - Center 49.5 8.0 8.0 133,5 130.1 97 A N 95 Pass 12 Building Pad 1 -West 49.5 8.0 9.7 133.5 126.6 95 A N 95 Pass 13 Building Pad 2 - Gi 47.0 8.0 9.0 133.5 126.8 95 A N 95 Pass 14 Building Pad 2 - Stairway G1/G2 47.5 8.0 9.4 133.5 126.7 95 A N 95 Pass 15 Building Pad 2- Gi 48.0 8.0 8.6 133.5 126.5 95 A N 95 Pass 16 Building Pad 2- G2 48.0 8.0 8.1 133.5 126.9 95 A N 95 Pass 17 Building Pad 2 - G2 48.0 8.0 8.6 133.5 127.7 96 A N 95 Pass 18 Building Pad 2 - G4 48.0 7.0 7.8 137.0 131.8 96 B N 95 Pass 19 Building Pad 2 - Storage 48.5 7.0 8.2 137.0 130.4 95 B N 95 Pass 11/16/11 20 Building Pad 2 - G6 50.0 7.0 5.9 137.0 124.0 91 B N 95 Fail 21 Building Pad 2 - G5 49.5 7.0 5.6 137.0 124.6 91 B N 95 Fail 20 R Building Pad 2- G6 50.0 7.0 8.1 137.0 129.9 95 B N 95 Pass 21 R Building Pad 2- G5 49.5 7.0 8.0 137.0 130.4 95 B N 95 Pass 22 Building Pad 2 - Stairway G5/G6 49.5 7.0 7.5 137.0 131.9 96 B N 95 Pass 23 Building Pad 2 - Stairway G6/Storage 49.0 7.0 8.4 137.0 129.9 95 B N 95 Pass 11/16/11 24 FG Building Pad 2 - G6 50.2 7.0 7.3 137.0 131.3 96 B N 95 Pass 25 FIG Building Pad 2- G5 49.5 7.0 7.7 137.0 131.1 96 B N 95 Pass 26 FIG Building Pad 2 -Trash Room 48.9 7.0 7.1 137.0 130.2 95 B N 95 Pass 27 FIG Building Pad 2 - Storage 48.9 8.0 8.6 133.5 127.1 95 A N 95 Pass 28 FIG Building Pad 2- G4 48.7 7.0 8.1 137.0 131.2 96 B N 95 Pass NOVA ENGINEERING AND ENVIRONMENTAL Lincoln and Oak Mixed Use S January 24, 2012 Carlsbad, California Project No. 10125-1011071.000 TABLE II - Summary of Compaction Test Results Test Depth/ Moisture Unit Dry Density Rel. Soil Test Proj. Date Number Test Location Elevation Opt. Field Max. Field Comp. Type Type Spec. Pass/Fail 11/16/11 29 FG Building Pad 2 - G3 48.2 8.0 8.8 133.5 127.6 96 A N 95 Pass (cont.) 30 FG Building Pad 2 - G2 48.4 7.0 7.5 137.0 133.8 98 B N 95 Pass 31 FG Building Pad 2 - G1 48.6 8.0 8.3 133.5 129.5 97 A N 95 Pass 11/18/11 32 FG Building Pad 1 - West 50.2 8.0 6.9 133.5 131.3 98 A N 95 Pass 33 FG Building Pad 1 - Center 50.2 8.0 6.2 133.5 130.8 98 A N 95 Fail 34 FG Building Pad 1 - East 50.2 8.0 7.6 133.5 130.6 98 A N 95 Pass 35 FG Parking Garage - West 48.2 7.0 6.8 137.0 131.7 96 B N 95 Pass 36 FG Parking Garage - West 48.3 7.0 6.4 137.0 132.7 97 B N 95 Pass 37 FG Parking Garage - Center 47.8 7.0 4.4 137.0 118.7 87 B N 95 Fail 38 FG Parking Garage - East 48.2 7.0 4.6 137.0 117.2 86 B N 95 Fail 11/22/11 37 R Parking Garage - Center 47.8 7.0 8.5 137.0 130.0 95 B N 95 Pass 38 R Parking Garage - East 48.2 7.0 8.0 137.0 130.6 95 B N 95 Pass 39 FG Parking Garage - Center 47.0 7.0 8.1 137.0 130.1 95 B N 95 Pass 40 FG Parking Garage - East 48.5 7.0 7.9 137.0 130.7 95 B N 95 Pass 41 FG Driveway - North 50.0 7.0 7.4 137.0 129.8 95 B N 95 Pass NOVA ENGINEERING AND ENVIRONMENTAL