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HomeMy WebLinkAboutCT 06-15; TABATA RANCH; INTERIM AS-GRADED GEOTECHNICAL REPORT; CDP 16-09, CDP 16-10, CDP 16-11, CDP 16-26, CDP 16-27, DWG 480-5A, DWG 480-5B, DWG 480-5C, DWG 480-5D, DWG 480-5E, DWG 480-5F; 2015-08-02-CTE~ Construction Testing & Engineering, Inc. Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering 1 ·surveying INTERIM AS-GRADED GEOTECHNICAL REPORT PROPOSED TABATA RANCH SUBDIVISION LEMON LEAF DRIVE CARLSBAD, CALIFORNIA PREPARED FOR: TABATA FAMILY TRUST C/0: GREGG HARRINGTON P.O.BOX943 CARLSBAD, CALIFORNIA PREPARED BY: CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CALIFORNIA 92026 CTE PROJECT NO. 10-12101G JULY 6, 2015, MODIFIED AUGUST 2, 2015 --~-----·-· -----------· ------··---··----··-----------------------·. ·-- 1441 Montiel Road, Suite 115 I Escondido, CA 92026 I Ph (760) 7 46-1955 I Fax (760} 7 4&-9806 I www.cte-inc.net TABLE OF CONTENTS SECTION PAGE 1.0 BACKGROUND ....................................................................................................................... 1 2.0 PROJECT INFORMATION .............................................................. : ....................................... 2 3.0 FILL PLACEMENT ..................................................................... : ............................................ 3 4.0 TESTING ................................................................................................................................... 3 5.0 ADDITIONAL CONSTRUCTION OBSERVATION ................. ; ........................................... .4 6.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................... .4 7.0 LIMITATIONS .......................................................................................................................... 5 TABLES TABLE I TABLE II FIGURES FIGURE 1 FIGURE2 COMP ACTION TEST SUMMARY LABORATORY TEST DATA SITE INDEX MAP COMP ACTION TEST LOCATION MAP \\Esc _server\projects\I0-12101G\Rpt_Interm Comp 10-12101 [07-06-2015].doc Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 Page 1 CTE Job No. 10-12101G LO BACKGROUND This document provides information regarding testing of compacted fill for the grading operations completed in 2014 at the proposed Tabata Ranch Subdivision located on Lemon Leaf Drive in Carlsbad, California. Our work was authorized through CTE proposal no. G-3191, dated June 1, 2014. Part of the site was previously graded (Lots 1 and 2) based on the preliminary geotechnical investigation performed by Vinje & Middleton Engineering, Inc. (Job No. 01-364-P) dated August 2, 2006. Grading procedures and testing of compacted fill for these lots was conducted by Vinje & Middleton Engineering, Inc. personnel. CTE reviewed field grading observation reports from the testing and observations of these lots, in addition to performing surface testing on these two lots, with adequate compaction test results. CTE also reviewed the previously prepared geotechnical report and was in general agreement with the data, conclusions, and recommendations. Based on the previously performed limited investigation, the site had Quaternary Previously Placed Fill soils overlying sedimentary bedrock units of the Eocene Age. Fill soils were generally found to a maximum depth of 5 .5 feet below existing grades. The attached Figure 1 shows the approximate location of the site and surrounding area. \\Esc _ server\projects\10-12101 G\Rpt_Intenn Comp 10-12101 [07-06-2015].doc Page2 Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 CTE Job No. 10-12101G 2.0 PROJECT INFORMATION This report includes a summary of test results and observations performed by CTE during the recent (2014) placement of compacted fill for the proposed building pads and associated improvements. Conditions encountered at the site were found to consist of previously placed fill and residual soils overlying sedimentary bedrock. Previously placed fill and other disturbed near surface soils were generally found to consist ofloose, silty sand. These materials were removed beneath improvement areas prior to placement of compacted fill as part of the recent grading operations. As indicated, loose and disturbed surface soils and previously placed fill were excavated to between elevations 253 feet above mean seal level (msl) and 272 msl, depending on location. The exposed bottoms of excavations were observed, tested, and confirmed ( as appropriate) prior to placement of the compacted fill. Exposed areas to receive fill were then scarified, moisture conditioned, and compacted in general accordance with project requirements. Following subgrade preparation, fill materials were moisture conditioned, placed in thin uniform lifts, and then compacted. Excavations and compaction within the improvement areas were conducted with a D8 bulldozer and a 980 rubber-tired front loader. Mountain Movers was the grading contractor for the project. Additional grading throughout the subject site consisted of parking and drive areas, minor excavations, wall backfill, and utility installation. Minor grading and compaction testing for utility tie-ins conducted in the adjacent Lonicera Street right-of-way is also documented herein. \\Esc_server\projects\10-12101G\Rpt_ Interm Comp 10-12101 [07-06-2015].doc Page3 Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 CTEJob No. 10-12101G 3.0 FILL PLACEMENT Fill soils consisting of onsite stock piled materials were generally placed in uniformly compacted lifts at above optimum moisture content. Compaction was performed to the appropriate minimum values (90% for building pad areas and 95% for pavement sub grade areas), as determined by ASTM Dl557. Grading was performed using standard construction equipment, followed by mixing, moisture conditioning, and compaction procedures. Backfill placement and compaction were performed in overall conformance with the project geotechnical recommendations. 4.0TESTING Testing was performed to supplement field observations. Testing of compacted fill addressed by this report was conducted, as scheduled by the contractor, between July I, 2014 and November 10, 2014. Field-testing of the compacted fill soil was conducted in accordance with ASTM D-693 8-08a (nuclear method). Results of the field-testing indicate that fill materials were compacted to at least 90 percent or 95 percent ( depending on location) of the laboratory maximum dry density, as required, in accordance with ASTM D 1557. Fill material was generally compacted at above optimum moisture content. Tabulated results of the field compaction testing are provided in the attached Table I, "Compaction Test Summary." Laboratory determination of the reference compaction values for the fill materials is provided in Table II, "Laboratory Test Results." Figure 2 shows the approximate location of the compaction tests performed, as well as other pertinent as-graded information. \\Esc _server\projects\10-12101 G\Rpt_Intenn Comp 10-12101 [07-06-2015].doc Page4 Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 CTE Job No. 10-121010 Based on site observations and laboratory testing, it appears the expansion potential for onsite materials is generally very low (Expansion Index < 20). 5.0 ADDITIONAL CONSTRUCTION OBSERVATION CTE observed subsurface water seepage along the dense formation contact during the overexcavation of the lower building pad (proposed elevation 276.0 feet) of Lot 3. Based on our observations and discussions, the installation of a subdrain, which consisted of a typical minimum four-inch diameter perforated pipe, surrounded by 3/4-inch rock/gravel, and surrounded by filter fabric, was installed and connected to the south end of the adjacent retaining wall backdrain. The subdrain extended along the entire Lot 3 toe of slope that connects the upper and lower building pads. Additional grading and backfilling, if any, should be observed and tested by CTE. In addition, prior to any significant future development, an appropriate update geotechnical investigation and report should be completed; 6.0 CONCLUSIONS AND RECOMMENDATIONS CTE concludes that the soil engineering and engineering geologic aspects of the grading covered by this report are in compliance with the approved geotechnical report and the grading plans (City of Carlsbad Drawing No. 471-9A, Assessors Parcel Numbers APN: 214-631-20 & 214-630-20). However, we understand that the site structures are not proposed for construction at this time. Therefore, prior to commencing with future construction, CTE should review the final proposed structural locations and details in order to provide update recommendation for building pad \\Esc _)erver\projects\10-12101 G\Rpt_ Interm Comp 10-12101 [07-06-2015].doc Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 Page5 CTE Job No. 10-12101G overexcavations, as appropriate. Due to the passing of time since building pad preparations, at a minimum, surficial remediation should be anticipated prior to recommencing building construction. Any vegetation, debris, or any other loose or dry material should be removed and replaced by compacted backfill to the required subgrade elevations, as necessary. As such, we anticipate (at a minimum) it will be appropriate to remove any vegetation and then scarify, moisture condition, and recompact the top six to 12 inches of building pad sub grade soils. However, CTE should confirm the adequacy of the building pad and surrounding areas during construction. CTE should also observe and confirm all footing excavations, as they are performed, in order to confirm adequate conditions. 7.0 LIMITATIONS As limited by the scope of the services that CTE agreed to perform, opinions presented herein are based on observations, test results, and understanding of the proposed site development. CTE's service was performed according to the currently accepted standard of practice by reputable consultants. No warranty, express or implied, is given or intended with respect to the performance of the project in any respect. Submittal of this report should not be construed as relieving the grading contractor of his responsibility to comply with the project requirements. The opportunity to be of service is appreciated. If you have any questions regarding testing conducted, observations made during construction or recommendations presented herein, please do not hesitate to contact this office. \\Esc _server\projects\10-12101 G\Rpt_ Interm Comp 10-12101 [07-06-2015].doc Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California July 6, 2015, Modified August 2, 2015 Respectfully submitted, Page6 CTE Job No. 10-12101G CONSTRUCTION TESTING & ENGINEERING, INC. Dan T. Math, GE #2665 Principal Engineer RJJ/DTM:nri \\Esc _ server\projects\10-121 OIG\Rpt_ Interm Comp 10-12101 [07-06-2015].doc Job Nattiet \ .. ' . ~ '. ' . ~ . ,IoltAd4tt&~: \ · ··uate · · ·rest No: 7/1/2014 1 7/1/2014 2 7/1/2014 3 7/1/2014 4 7/1/2014 5 7/1/2014 6 7/2/2014 7 7/2/4014 8 7/2/20i4 9 7/2/2014 10 7/2/2014 11 7/2/2014 12 7/2/2014 13 7/2/2014 14 7/2/2014 15 7/2/2014 16 7/2/2014 17 7/V2014 18 7/3/2014 19 7/3/2014 20 7/3/2014 21 7/3/2014 22 7/7/2014 23 7/7/2014 24 7/7/2014 25 7/7/2014 26 7/7/2014 27 7/7/2014 28 7/8/2014 29 7/8/2014 30 7/8/2014 31 7/8/2014 32 7/8/2014 33 7/8/2014 34 7/8/2014 35 7/8/2014 36 7/8/2014 37 7/8/2014 38 7/9/2014 39 7/9/2014 40 7/9/2014 41 7/9/2014 42 7/9/2014 43 7/9/2014 44 7/9/2014 45 7/9/2014 46 7/10/2014 47 TABLE I COMPACTION TEST SUMMARY '.i'abata Ranch · Job No. Lemon Leaf I>rive, Carlsbad Date: Location Elevation Density or Depth pcf Feet Strawberrv Place/Street 254.0 114.8 Strawberry Place/Street 256.0 115.2 Strawberry Place/Street 256.0 114.1 Strawberrv Place/Street 258.0 113.7 Strawberrv Place/Street 260.0 112.5 Strawberrv Place/Street 260.0 114.0 Strawberrv Place/Street 258.0 114.7 Strawberrv Place/Street 262.0 113.3 Strawberrv PlacefStreet 262.0 115.1 Strawl;,errv Place/Street 264.0 115.9 Strawberrv Place/Street 264.0 113.8 Strawberry Place/Street 263.0 116.4 Strawberrv Place/Street 265.0 114.5 Strawberrv Place/Street 265.0 115.0 Strawberrv Place/Street 263.0 113.9 Strawberrv Place/Street 267.0 113.8 Strawberrv Place/Street 267.0 116.0 Strawberrv Place/Street 265.0 115.7 Strawberrv Place/Street 269.0 114.2 Strawberrv Pl~ce/S~et 269.0 113.7 Strawberrv Place/Street 264.0 119.0 Strawberrv Place/Street 266.0 117.0 Strawberrv Place/Street 266.0 116.3 Strawbeny Place/Street 266.0 115.5 Strawberrv Place/Street 268.0 118.2 Strawberrv Place/Street 268.0 118.5 Strawberrv Place/Street 270.0 116.6 Strawberrv Place/Street 270.0 115.9 Lot 5 Fill Slope 265.0 110.0 Lot 5 Fill Slope 267.0 111.2 Lot 5 Fill Slope 267.0 111.6 Lot 5 Fill Slope 269.0 110.3 Lot 5 Fill Slope 269.0 109.4 Lot 5 Fill Slope 271.0 105.7 Lot 5 Fill Slope 271.0 108.0 Lot 5 Fill Slope 271.0 109.1 Strawberrv Place/Street 271.0 108.6 Strawberrv Place/Street 271.0 110.7 Lot4 273.0 113.4 Lot4 273.0 110.1 Lot4 273.0 112.4 Lot4 274.0 110.3 Lot4 274.0 109.3 Lot4 274.0 111.8 Lot5 273.0 112.0 Lot5 273.0 109.5 Lot 3/Upper Pad 284.0 105.3 ** TEST FAILED, SEE RETEST 1 . 10_;l21-0J(L ··•· .. 07/06/02015 '.Moisiure. . Relative . Soil'. · Content· Compaction Type· %Dry % Weitth.t 9.8 91% 1 10.3 92% 1 10.5 91% 1 10.9 90% 1 11.9 91% 2 12.3 92% 2 12.8 92% 2 12.6 91% 2 12.2 93% 2 11.4 93% 2 11.8 92% 2 12.7 94% 2 12.0 92% 2 12.3 93% 2 11.1 92% 2 11.5 92% 2 12.4 93% 2 12.0 93% 2 12.4 92% 2 11.6 91% 2 11.8 96% 2 12.6 94% 2 12.2 94% 2 12.0 93% 2 11.7 95% 2 12.0 95% 2 12.4 94% 2 13.3 93% 2 15.1 95% 3 15.7 97% 3 14.9 97% 3 15.9 96% 3 13.6 95% 3 13.5 92% 3 14.4 94% 3 14.0 95% 3 14.5 94% 3 15.2 96% 3 13.5 98% 3 13.8 96% 3 13.6 98% 3 12.9 96% 3 13.2 95% 3 13.7 97% 3 14.2 97% 3 14.8 95% 3 15.1 91% 3 Job NB}rl,e: Job A,q!:4"f,ss: ··.Date •. Test .No. 7/10/2014 48 7/10/2014 49 7/10/2014 50 7/10/2014 51 7/10/2014 52 7/10/2014 53 7/11/2014 54 7/11/2014 55 7/11/2014 56 7/14/2014 57 7/14/2014 58 7/14/2014 59 7/14/2014 60 7/14/2014 61 7/15/2014 62 7/15/2014 63 7/15/2014 64 7/15/2014 65 7/15/2014 66 7/15/2014 67 7/16/2014 68 7/16/2014 69 7/16/2014 70 7/16/2014 71 7/17/2014 72 7/17/2014 73 7/17/2014 74 7/17/2014 75 9/4/2014 76 9/4/2014 77 9/4/2014 78 9/4/2014 79 9/4/2014 80 9/4/2014 81 9/4/2014 82 9/4/2014 83 9/4/2014 84 9/4/2014 85 9/4/2014 86 9/5/2014 87 9/5/2014 88 9/5/2014 89 9/5/2014 90 9/5/2014 91 -92 -93 10/10/2014 94 TABLE I COMPACTION TEST SUMMARY tabata Ranch Job-No'.. . Lem,on Leaf Drive. Ca,rlsbad Date: Location . ;eievation Densjty or Depth pcf Feet Lot 3/Unner Pad 285.0 106.6 Lot 3/Unner Pad 284.0 107.0 Lot 3/Uorier Pad 285.0 105.1 Lot5 273.0 108.4 Lot5 273.0 111.3 Lot5 273.0 112.0 Lot5 274.0 111.7 Lot5 274.0 111.1 Lot5 274.0 110.8 Lot 3/Lower Pad 273.0 107.5 Lot 3/Lower Pad 274.0 107.7 Lot 3/Lower Pad 275.0 109.0 Lot 3/Uooer Pad FSG 105.5 Lot 3/Unner Pad FSG 106.1 Lot5 FSG 113.0 Lot5 FSG 1122 Lot5 FSG 111.5 Lot4 FSG 109.8 Lot4 FSG 112.0 Lot4 FSG 110.3 Lot 1 FSG 120.6 Lot 1 FSG 119.9 Lot2 FSG 122.8 Lot2 FSG 121.0 Rebuild Fill Slope at Lot 3 Wall 286.0 109.2 Rebuild Fill Slope at Lot 3 Wall 287.0 109.5 Rebuild Fill Slope at Lot 3 Wall 288.0 109.9 Rebuild Fill Slope at Lot 3 Wall 288.0 110.6 Retaining Wall East of S:trawberrv Place 276.0 106.3 Retaining Wall East of Strawberrv Place 275.0 103.9 Retaining Wall East of Strawberrv Place 273.0 105.6 Retaining Wall East of Strawberrv Place 272.0 105.1 Retaining Wall East of Strawberrv Place 270.0 104.5 Retaining Wall Ea,st of Strawberrv Place 269.0 111.9 Retaining Wall East of Strawberrv Place 262.0 113.5 Retaining Wall East of Strawberrv Place 277.5 112.9 Retaining Wall East of Strawberrv Place 273.0 103.8 Retaining Wall East of Strawberrv Place 268.0 108.3 Retaining Wall East of Strawberrv Place 264.5 107.5 Retaining Wall South ofStrawberrv Place 250.0 105.7 Retaining Wall South of Strawberrv Place 251.0 104.4 Retaining Wall South ofStrawberrv Place 252.0 106.9 Retaining Wall South of Strawberrv Place 253.0 104.1 Retaining Wall South of Strawberrv Place 254.0 105.4 Not Used -- Not Used - - Back Horseshhoe Shape Wall 2' Below Top of Wall 272.0 105.1 ** TEST FAILED, SEE RETEST 2 IO~ 12.i.Oi-Ci" 07/06/02015 . Mois:tut~ .·· .· ·i.l¢lative Soil c9nt~~1: Gompaction Type %Dfy % .W~ii:i'ht 15.3 93% 3 15.0 93% 3 15.5 91% 3 14.2 94% 3 14.0 97% 3 14.6 97% 3 14.8 97% 3 15.0 96% 3 14.4 96% 3 12.9 93% 3 13.5 93% 3 14.9 95% 3 15.3 92% 3 15.6 92% 3 14.4 98% 3 14.0 97% 3 13.9 97% 3 13.1 95% 3 13.6 97% 3 13.7 96% 3 5.4 97% 2 6.0 96% 2 6.7 99% 2 6.9 97% 2 12.5 95% 3 13.8 95% 3 14.0 95% 3 14.2 96% 3 12.8 92% 3 13.4 90% 3 12.9 92% 3 13.8 91% 3 13.6 91% 3 12.1 90% 2 10.9 91% 2 11.7 91% 2 13.3 90% 3 13.7 94% 3 14.4 93% 3 14.1 92% 3 13.9 91% 3 14.6 93% 3 12.5 90% 3 13.8 91% 3 -NIA - -NIA - 13.2 91% 3 -------------------------------------------------------------- JohNw.e: JQb A.ddtes$: Date Test No. 10/10/2014 95 10/10/2014 96 10/10/2014 97 10/10/2014 98 10/10/2014 99 7/28/2014 100 7/28/2014 101 7/29/2014 102 7/29/2014 103 10/23/2014 104 10/23/2014 105 10/27/2014 106 10/27/2014 107 10/29/2014 108 10/31/2014 109 11/10/2014 110 11/10/2014 111 11/10/2014 112 11/10/2014 113 tabataRimch TABLE I COMPACTION TEST SUMMARY .ri;ih::NQ. - _ u:IQ.on ~afDrive, Carlsba<;l t>fl,~: -----10'-121ofd 07/06/0ZOlS Location -Ele~atlon· ---Density · --• ·Moisture _ orDepth pcf Content Feet %Dry Weil!:ht Back Horseshhoe Shape Wall 2' Below Top of Wall 270.0 104.8 12.9 Back Horseshhoe Shape Wall 2' Below Top of Wall 267.0 104.4 13.4 Back Horseshhoe Shape Wall 2' Below Top of Wall 262.0 105.7 10.5 Back Horsesbhoe Shape Wall 2' l3elow Top of Wall 272.0 107.9 10.9 Back Horseshhoe Shape Wall 2' Below Top of Wall 270.0 107.6 11.3 Lower Ha'.lf of Slope (Sewer) -2.0 108.2 14.9 Lower Ha'.lf of Slope (Sewer) -1.0 106.0 15.3 Lower Ha'.lf of Slope (N. Sewer) -1.0 106.3 14.5 Lower Half of Slope (N. Sewer) -2.0 105.2 15.2 SDI-storm drain on Lonicera St 244.0 110.6 14.1 SD2-stonn c1rain on Lonicera St SG 107.6 15.8 Stonn Drain Manhole -2.0 110.2 14.6 Stonn Drain Manl;tole FSG 112.3 15.1 Stor;m Drain Tie-In SG 111.2 13.1 Sewer Tie-in SG 114.4 13.3 8-inch Sewer Line 250.0 109.6 12.7 8-inch Sewer Line 252.0 112.7 12.7 8-inch Sewer Line 253.0 110.4 13.1 8-inch Sewer Line 254.0 109.8 12.9 ** TEST FAILED, SEE RETEST 3 --_ Relative .·son··_ -Conipaction 1 ..... ·Type % 91% 3 91% 3 92% 3 94% 3 93% 3 94% 3 92% 3 92% 3 91% 3 96% 3 93% 3 96% 3 97% 3 97% 3 99% 3 95% 3 98% 3 96% 3 95% 3 Jc;,b Name: tafiata'Rmicii · J~b Address: Lemon Leaf Prive, Carl~b~d Maximum Sample No. Dry Density pcf 1 125.9 2 124.3 3 115.2 TABLE II LABORATORY TEST DATA Optimum Moisture Content %wt 9.5 10.0 12.3 4 J9~N.o. Dat~ ·10:121010 ,' 7/6/ZQIS Soil Description Light brown silty SAND with rock correction Light brown silty SAND Yellowish brown silty SAND . . \ \ \ ,:; / ,/ ', .,·.,· ./" \~, ' . . ,'\ ..... . \ ~- ,,- . ( .. ~ .:.~. -'-li,,;,:;,~ .::·,~::-..::. . .;; c~ Construction Testing & Engineering, Inc. . ~c 1441 Montiel Rd Ste 115, Esccndido, CA 92026 Ph (760) 7464955 SITE INDEX MAP PROPOSED TABAT! RANCH SUBDIVISION LOON WF DRIVE CARISBAD, CALD'ORNJA SCALE: AS SHOWN CTE JOB NO.: 10-12101G DATE: 07/15 FIGURE: 1 r , Lw •• ,.J ~, UJ u.. 0 z t; Qw ~ l-o z oQ ...J 1-w () I--5. z 0 ~ > w ...J w w (fJ I--!