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Home My WebLink AboutCT 03-06; BLACK RAIL 16; AS GRADED GEOTECHNICAL REPORT; 2014-05-29I . . .C1 0 ~7 - bife U SOUTHERN CALIFORNIA Corporate Headquarters 6280 Riverdale Street I (!LSOIL & TESTING, INC. San Diego, cA9212o SBE I SLBE I DVBE I SDVOSB . Toll Free: 877.215.4321 w.scst.com May 29, 2014 SCS&T No. 1311204 Report No. 5 I Mr. Marty McComas Davidson Communities 1302 Camino Del Mar I Del Mar, California 92014 Subject: AS-GRADED GEOTECHNICAL REPORT I . BLACK RAIL ROAD —16—SUBDIVISION CARLSBAD, CALIFORNIA I Dear Mr. McComas: PROJECT DESCRIPTION I Southern California Soil and Testing, Inc. (SCS&T) prepared this report to present the results of field observations and compaction testing performed during earthwork for the subject project. This report I presents a summary of SCS&T's observations and testing between May 7, 2014 and May 27, 2014. To assist in locating our field density tests, we were provided the referenced precise grading plan I prepared by Fuscoe Engineering, dated January 18, 2014. SITE PREPARATION I Site preparation began with the clearing and grubbing of the existing vegetation and debris. These materials were exported from the site. The mass grading consisted of excavating about 2 feet below the planned finish pad grade elevation. The surface exposed at the bottom of the I excavations was scarified to a depth of 6 inches; moisture conditioned, and compacted until field density tests indicated a minimum of 90% relative compaction. Figure 1 presents the excavation I bottom elevations. Excavated material free of organics and deleterious material was placed as compacted fill. The material was moisture conditioned and compacted until field density tests indicated a minimum of 90% relative compaction. Fill was placed until planned pad elevations were achieved. All references to optimum moisture and relative compaction in this report are based on the ASTM D 1557 laboratory test method. Figure 1 presents the approximate density test locations. I AS-BUILT GEOLOGY In our opinion the geological conditions exposed at the site were found to be similar to those I described in the referenced geotechnical report and generally as anticipated. Additionally it is our opinion that the site is suitable for the planned construction. I . I H . San Diego Los Angeles Inland Empire Central Valley I Davidson Communities - May 29, 2014 I Black Rail Road 16 SCS&TNo. 1311204-05 Carlsbad, California Page 2 I FIELD OBSERVATIONS AND TESTING Field density tests were performed in accordance to ASTM D6938 (nuclear gauge) procedures. Figures 2 through 3 present the test results. The accuracy of the in situ density test locations and I elevations is a function of the accuracy of the survey control provided by others than SCS&T representatives. Unless otherwise noted, their locations and elevations were determined by pacing and hand level methods and should be considered accurate only to the degree implied by the method used. As used herein, the term "observation" implies only that we observed the progress of work for which we were involved. We performed field density tests, which in conjunction with our observations, were the base for our opinion as to whether the work performed was in substantial conformance with the geotechnical recommendations and the requirements of the applicable agencies. A maximum dry density test was performed on two representative samples of the soil used in the compacted fill according to ASTM D1557. The results of these tests, presented on Figure 3, were used in conjunction with the field density tests to determine the degree of relative compaction of the compacted fill. The soluble sulfate content was determined in accordance with California Test 417. The soluble chloride content was determined in accordance with California Test 422. Expansion index results were determined in accordance with ASTM D4829. Figure 3 presents the test results. I CONCLUSIONS Based on our field observations and the in-place density test results, it is the opinion of SCS&T that I the geotechnical engineering aspects of the grading are in compliance with the referenced geotechnical report, the City of Carlsbad Grading Ordinance, and the California Building Code. In I our professional opinion and to the best of our knowledge, the site appears to be suitable for the planned construction. LIMITATIONS This report covers only the services performed between May 7, 2014 and May 27, 2014. Our opinions are based on our observations and the relative compaction test results and are limited by the scope of the work that we agreed to perform. Our work was performed in accordance with the currently accepted standard of practice and in such a manner as to provide a reasonable measure of the compliance of the grading and backfill operations with the project requirements. No warranty, express or implied, is made or intended with respect to the work that we have performed, and neither the performance of this work nor the submittal of this report should be construed as relieving the contractor of its responsibility to conform with the project requirements. Our work was generally performed on an "on-call" basis. Therefore, the in-place density tests performed by our field representative can only be construed as representative of the areas tested as shown on the attached figures. & Davidson Communities May 29, 2014 Black Rail Road 16 SCS&TNo. 1311204-05 Carlsbad, California Page 3 Should you have any questions regarding this document or if we may be of further service, please contact our office at your convenience. Respectfully Submitted, oESSiO4 SOUTHERN LIFOMAOILAND TESTING, INC. EOLOGIST Uj NO. 275 M ount rew K. Neuhaus, CEG 2591 Principal Geotechi Senior Engineering Geologist --. GBF:AKN:EAK:aw FE,Ø ATTACHMENTS. K. Figures (( co (('c NO. 2591 c r Exp.9,3 ) Figure 1 - In-Place Density Test Location Map cc D JJ ENGINEERING Figure 2 through 3 - In-Place Density and Laboratory Test Results GEOLOGIST (1) Cheryl Landes via e-mail at: clandesdavidsoncommunities. corn (1) Marty McComas via e-mail at: MMCComas(davidsoncomm unities. corn (1) George Sturgeon via e-mail at: gsturgeon(davidsoncornm unities. com I Davidson Communities May 29, 2014 I Black Rail Road 16 S I SCS&TNo. 1311204-05 Carlsbad, California Page 4 I REFERENCES 1. 'Preliminary Geotechnical Investigation, Proposed 17-Lot Subdivision, Black Rail Road, Carlsbad, APN 215-080-20,21,28"; prepared by Vinje and Middleton, Inc., dated May 22, 2003. Project Number 03-236-P 2. "Interim Report of Geotechnical Testing and Observation During Earthwork Construction, Lots I through 16, Black Rail TM No. 2-026"; prepared by GeoTek, Inc., dated July 25, I 2007, Project Number 3103SD3. "GeotechnicalExplorationand Review of Precise Grading Plan for Carlsbad 16 Project, Lots I . 1 through 16 of Map 15521, Carlsbad, California- DRAFT'; prepared by NMG Geotechnical, Inc., dated November 30, 2012, Project Number 12115-01. "Update Geotechnical Report, Black Rail Road - 16 Subdivision, Carlsbad, California", I prepared by Southern California Soil and Testing, Inc., dated December 31, 2013. Precise Grading Plans, Carlsbad 16, Lots 1-16 of Map 15521, Sheets 1 through 4, prepared by Fuscoe Engineering, January 18, 2014. I , S ... .5 .. I I I I I I TEST ELEVATION MOISTURE DRY DENSITY SOIL REL.COMP. NO. DATE LOCATION (feet,MSL) (percent) (p.c.f.) TYPE (percent) GRADING'. 1 5/7/14 - Lot #15-North PAD. 374.0 11.7 115.9 1 92.1 2 5/7/14 Lot# 15- North PAD 374.0 ' 12.2 113.8 .1 90.4 3 - 5/7/14 Lot# 14-North PAD .' 374.0 12.0 115.1 1 91.4 4 5/7/14 Lot# 14- North PAD 374.0 11.3 113.7 1 90.3 5 5/7/14 Lot# 13- North PAD 372.0 13.0 114.6 1 191.0 6 5/7/14 , " Lot # 13 - North PAD ' , 372.0 '.12.0 114.4 1 90.9 7 5/8/14 Lot# 15- South PAD 374.0 13.2 113.5 1'' 90.2 8, 5/8/14 . Lot# 14- South PAD . 374.0 10.1 117.8 1 93.6 9 5/8/14 Lot# 12- North PAD 366.5 10.9 , 115.6.. 1 91.8 '10 5/8/14 Lot#12-North'PAD 366.5 11.1 117.7 .1 ' 93.5 11 5/9/14 Lot 11- North PAD 362.0 9.7 113.8 1 90.4 12' 5/9/14. Lot# 11-North PAD . .' 362.0 ,- 10.6 118.1 . 1' 93.8 13 5/9/14 Lot #13- South PAD ' . 372.0 .'14.2 114.9 1 91.3 14 5/9/14 Lot# 9-North PAD ' 355.0 9.7 113.9 . 1 90.5 15 5/9/14 , ' Lot #9- North PAD " 355.0 9.9 ' , 114.5 1 - 90.9 16 5/9/14 Lot# 10 -North PAD .- . 357;0 8.6 ' 116.4 1 ' 92.5 17 5/9/14 ' Lot# 10-North PAD -.' 357.0: 10.4 113.7. . 1 90.3 18 5/12/14 Lot #'l -South PAD 373.5 13.0 114.0 .1 90.5 19 5/12/14 . Lot# 1 - Middle PAD 3735' - 12.5 113.4 1 90.1 20 5/12/14 Lot# 1 - North PAD .. ' .373.5 13.2 115.6 . ' :1 .. 91.8 21 5/12/14 Lot# 4-South PAD 371.0 -11.3 - .. 114.3 1 90.8 22 5/12/14 ' -Lot #4 - Middle PAD ' 371.0, - , 10.7 113.5 ' '1 ' 90.2 23 5/12/14' Lot #4 - North PAD 371.0 12.2 117.1 1 ' 93.0 24 5/13/14 . Lot# 11 - South PAD - 362.0 .11.4 - 114.7 1 91.1 25 5/13/14' - Lot# 8- South PAD' 356.0,, 1110 116.5 1' . 92.5 26 5/13/14 Lot #'4 FG 373.0 123 1171 1 930 27 5/13/14 ' Lot# 2-South PAD * ' -- 374.0 '11.3 . 116.4 -1 '92.5 28 '5/14/14 Lot# 10-South PAD 355.0 , - 12.4 114.4 1 90.9 29 5/14/14 Lot# 9-South PAD 3550 11.'6 1135 1 902 30 5/14/14 . Lot# 12- South PAD 366.5 ' ':11:4 115.8 . 1 92.0 31 5/14/14 Lot #3- South- PAD' - - 373.5 13.2 114.6 1 91.0 32 . 5/14/14 Lot# 3 :North PAD . . 373.5 '.11.8 ' 113.9 - - I ' 90.5 33 5/14/14 , Lot# 7-South PAD -' ' -358.5 . 12.4. 119.3 1 94.8 34 5/14/14 Lot # 7 - South PAD 358.5 .14 .3 '116.5 1 92.5 35 -5/14/14 - ..Lot# 6- South PAD ' . ' '364.5 9.9 114.3 - 1. 90.8 36 5/14/14 . ,Lot #6 -South PAD ' . 364.5 12.2 . ' 115.6 1 - 91.8 -37 5/14/14 Lot# 5-South PAD' ' 367.5 13.1 - - 110.4 1. . ' 87.7 :38 5/14/14 . Lot# 5-South PAD'' ' 367.5 12.3 - 115.8 1 ' 92.0 39 5/14/14 I, , Retest #37 '-'., ' ' 367.5 . 12.5' - 117.2 - 1 - 93.1 , 40. 5/14/14 , ,' Lot# 16- North PAD'. , 370.0' '. - 10.3 ' - 115.0 1 91.3 41 5/14/14. '-' Lot #16- North PAD 370.0 111 113.7 1 90.3 42 5/16/14 Lot# 16- South PAD 3695 55 117.1 1 930 - 43 5/17/14 Lot# 5 - North PAD - 367.5' 12.3 117.8 1 93.6 44 5/17/14 • Lot #6 - North PAD., - :364.5 .10.2 ' 121.4 - I 96.4 45 5/17/14 - Lot# 7-North PAD - - - 358.5'' 11.6 119.5 1 - 94.9 46 - 5/17/14 . Lot# 8- North PAD: ' 356.0 ,. 10.9 - 115.0 1 91.3 47 5/27/14 -' Lot 9 ' . '' .- FG 357:0 -'. - 8.4 122.6 2 95.9 48 5/27/14 ' Lot 101., FG 359.0 7.0 ,' 125.4 2 . 98.0 49 5/27/14 Lot 11 FG 364.0 55 1235 2 966 Figure No 2 I . ': :.:• JOB NAME: BLACK RAIL ROAD -16 -SUBDIVISION JOB NUMBER: 1311204-05 IN PLACE DENSITY TESTS RN I TEST ' - - ELEVATION MOISTURE DRY DENSITY SOIL REL.COMP. NO. ' DATE : LOCATION' :' (féet,MSL) (percent) (p.c.f.) TYPE (percent) 50 5/27/14 Lot 12 FG 368.5 6.7 . 126.3 2 98.7 I .51 5/27114 .-Lot 13 .• FG374.0 65 113.8 1 90:4 52 5127114. '. : Lot 14 . ' FG 376.0 6.5 ' 118.9 1. 94.4 53 :5/27/14 : Lot 15. ' FG 376.0 5.4 115.9 1 ' ' 92.1 54 5/27/14 Lot 16. . FG 372.0- ' 7.1 , 122.9 .- 2 , 96.1 I . 55 5/27/14 Lót1 ' ' FG 375.5 6.2. 114.7 1 91.1 56 5/27/14 Lot2 FG3760 79 1172 1 931 57 5/27/14 Lot FG3755 74 1159 1 921 58 5/27/14. I . Lot .. -: -FG 375.0 . 8:0.. 122.3 2 95.6 59 5/27/14 Lot FG 369.5 62 1147 1 911 60 5/27/17 Lot • FG 366.5'-, 78 1221 2 955 61 . '5/27/14. ' Lot 7 . ' ' FG 360.5 : 6.4 120.3 . 2 94.1 62 5/27/14 Lot FG3580 81 1194 2 934 I FG = Final Grade H MAXIMUM DENSITY: AND OPTIMUM MOISTURE SUMMARY (ASTM D1557) • Soil Maximum . Optimum I Type. Soil Description Density, pcf : Moisture, % Reddish Brown Silty Sand ......: - , 125.9 .. . 11.0 I 2 Brown Silty Sand 127.9 9.1 EXPANSION INDEX RESULTS '.' :1: . . EXPANSION . SAMPLE •. , . REPRESENT: .. EXPANSION. EXPANSION TEST SAMPLE. LOCATION LOTS ' INDEX POTENTIAL . El 1 . 0 feet to 5 feet ., ' -. Lot# 9 '19 . . . Very Low El 2 0 feet to 5 feet Lot # 6 28 Low El 3 . ' 0 feet to 5 feet , : . Lot # 8 ' . 23 . ' Low E14 0 feet to 5 feet ' Lot # 13 8 Very Low SULFATE TEST RESULTS, % BY WEIGHT I. SOLUBLE : -. .' . . SULFATE ' H SAMPLE '''' 'REPRESENT SULFATE- " 'SULFATE TEST SAMPLE : LOCATION - ' ' H LOTS : CONTENT(%) . EXPOSURE SS 1 • 0 feet to 5 feet - ' Lot # 9 .. 0.048 . , Negligible ,552 ' 0 feet to5feet . Lot #6 0.001 Negligible' $S3 , 0 feet to5feet • •. . ': • Lot#8. . 0.012 '. . Neligible SS 4 0 feet to 5 feet Lot # 13 6.009 Negligible o I ...!DETEST RESULTS, % BY WEIGHT SOLUBLE -' ', ' .'. :'' •. . ' I.. CHLORIDE : . SAMPLE' REPRESENT CHLORIDE CHLORIDE TEST SAMPLE :..' LOCATION LOTS-, - CONTENT (%) EXPOSURE SS 11 0 feet to 5 feet , -' ' - . . Lot # 9 : 0.01' • Non-corrosive SS 2 . - . 0 feet to 5 feet -. , ' ' . Lot # 6 . 0.01 • Non-corrosive SS 3 • 0 feet to 5 feet Lot # 8 • - 0.015 ' Non-corrosive SS 4 0 feet to 5 feet Lot # 13 0.015 Non-corrosive I - Figure NO. 3