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1996-4905 G 1 1 5f/(JS Category lfq()5 Name G-; Street Address / c¿; I ç, If;;¿ Serial # / Description Plan ck. # Year recdescv I NORTH COUNTY COMPACTION ENGINEERING, INC. February 18, 1997 Project No. CE-5325 Dan Davis 3369 Calle Margarita Olivenhain, CA 92024 Subject: Report of Certification of Compacted Fill Ground Proposed Davis Residence 3369 Calle Margarita Olivenhain; California I::' j rES L Dear Mr. Davis: i:::I\jC!N EE 1-\11";(;; ;.:;1:::-, \j ;\./ c;;:' CITY OF ENC!NITAS In response to your request, the following report has been prepared to indicate results of soil testing, observations, and inspection of earthwork construction at the subject site. Testing and inspection services were perfonned from January 6, 1997 through February 13, 1997. Briefly, our findings reveal filled ground has been compacted to a minimum of ninety percent (90%). Ther~fore, we recommend construction coptinue as scheduled. SCOPE Our fInn was retained to observe grading operations with regard to current standard practices and to detennine the degree of compaction of placed fill. Grading plans were prepared by Resource Development Corporation, dated December 5, 1996, Grading operations were perfonned by Lane Fukuda of V ista, California Reference is made to our previously submitted report entitled, "Preliminary Soils Investigation"; dated December 5, 1996. Approximate locations and depth of filled ground and extent of earthwork construction covered in this report are indicated on the attached Plate No. One entitled, "Test Location Sketch". Grading operations were perfonned in order to create a level building pad to accommodate raised floor construction and a detached garage. Should the finished pad be altered in any way, we should be contacted to provide additional recommendations. The site was graded in accordance with recommendations set forth in our previously submitted report. P.o. BOX 302002 . ESCONDIDO, CA 92030 (619) 480-1116 NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-5325 Page 2 ~RATORY TESTING Representative soils samples were collected and returned to the laboratory for testing. The following tests were peñormed and are tabulated on attached Plate No. Three. 1. Optimum MoisturelMaximum Density (ASTM D-l 557) 2. Expansion Potential Test SOIL CONDmONS Native soils encountered were clayey-sands, silty-clays, and clayey-sands. Fill soils were imported and generated from on-site excavation. The building site contained a transition from cut to fill. However, cut areas located within the building areas were over excavated a minimum of 3 feet and brought to grade with compacted soil. Over excavation was carried a minimum of 5 feet beyond the exterior building perimeter. Hence, no consideration need be given this characteristic. Soils were not imported as originally planned. Therefore, the site could not be graded selectively and soils possessing an expansion index of 100 exist at finish grade. Special foundations will be required to reduce the probability of structural damage occurring from excessive subgrade and foundation movement. Preliminary foundation recommendations presented in our "Preliminary Soils Investigation", dated December ,5, 1996, should not be utilized. Foundations should be constructed in accordance with the recommendations presented in this report. The key was approximately 15 feet wide and varied between 3 to 6 feet in depth, and was inclined back into slope. During earthwork construction, native areas to receive fill were scarified, watered, and compacted to a minimum of ninety percent (90%) of maximum density. Subsequent fill soils were placed, watered, and compacted in 6 inch lifts. Benches were consttucted in natural ground at intennediate levels to properly support the fill. To detennine the degree of compaction, field density tests were peñormed in accordance with ASTM D-1556 or D-2922 at the approximate horizontal locations designated on the attached Plate No. One entitled, "Test Location Sketch". A tabulation oftest results and their vertical locations are presented on the attached Plate No. Two entitled "Tabulation of Test Results". Fill soils found to have a relative compaction of less the ninety percent (90%) were reworked until proper compaction was achieved. ~COMMENDA TIQNS AN¡) CONCLUSIONS Continuous inspection was not requested to veritY fill soils were placed in accordance with current standard practices regarding grading operations and earthwork construction. Therefore, as economically feasible as possible, part-time inspection was provided. Hence, the following recommendations are based on the assumption that all areas tested are representative of the entire project. NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-5325 Page 3 1). Compacted fill and natural ground within the defined building areas have adequate strength to safely support the proposed loads. 1). Slopes may be considered stable with relation to deep seated failure provided they are properly maintained. Slopes should be planted within 30 days of this report with light groundcover (no gorilla ice plant) indigenous to the area. Drainage should be diverted away from the slopes to prevent water flowing on the face of slope. This will reduce the probability of failure as a result of erosion. 3). Temporary slopes to be retained and/or completed at a later date should be considered unstable and may prove to be a detrimental condition. Furthermore, we should be contacted to supervise backfill operations. Backfill materials should consist of non-expansive soils (having a swell of less than 2%) placed at a width behind the wall equivalent to two-thirds of the retained height. Crushed rock (I inch minus), approved by this office, may be an alternate method. All walls should be provided with drains. Drains should consist of 4 inch perforated pipe surrounded with crushed rock placed at a minimum of 2 cubic feet per lineal foot of pipe and have a minimum fall of one percent (1 %). A structural engineer should be contacted for a retaining devise recommendations. 4). Continuous footings having a minimum width of 12 inches and founded a minimum of 24 iriches below lowest adjacent grade for one and two stories, respectively, will have an estimated aUowable bearing value of 1200 pounds per square foot. S). Footings located on or adjacent to slopes should be founded at a depth such that the horizontal distance from the bottom outside face of footing to the face of the slope is a minimum of 8 feet. 6). Plumbing trenches should be backfilled with non-expansive soils having a swell of less than two percent (2%) and a minimum sand equivalent of 30. Back- fill soils should be inspected and compacted to a minimum of ninety percent (90%) 7). Unless requested, recommendations for future improvements (additions, pools, recreational slabs, additional grading, etc.) Were not included in this report. Prior to construction, we should be contacted to update conditions and provide additional recommendations. 8). Completion of grading operations were left at rough grade. Therefore, we recommend a landscape architect be contacted to provide finish grade and drainage recommendations. Drainage recommendations should include two percent (2%) fall away from all foundation zones. NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-5325 Page 4 9). Expansive soils conditions observed during grading operations will require special recommendations to reduce structural damage occurring from excessive subgrade and foundation movement. Recommendations set forth will reduce the probability of future damage and should be strictly adhered to: In the case for slab on grade foundations, all continuous footings should be founded a minimum of 24 inches below lowest adjacent grade. In the case of raised floor construction, exterior perimeter footings should be continuous and founded a minimum of 24 inches below lowest adjacent grade. Isolated interior footings should be founded a minimum of 24 inches below lowest interior grade. All continuous footings should be reinforced with two #5 bar top and bottom (a total of 4). Steel should be positioned 3 inches above bottom of footing and 3 inches below top of footing or finish floor. Garage slabs should be a minimum of 5 inches thick and reinforced at mid-point with #3 bars at 18 inches on center both ways. Garage slabs should be free floating and underlayed with 4 inches of washed sand with a visqueen moisture barrier installed at 'mid-point (2 inches $all~ visqueen, 2 ,inches sand). Sand should be tested in accordance with ASTM D-24 19 to insure a minimum sand equivalent of 30. Clayey soils should not be allowed to dry prior to placing concrete. They should be watered to insure they are kept in a very moist condition or at a moisture content exceeding optimum moisture content by a minimum of five percent (5%). Prior to pouring of concrete, North County COMPACTION ENGINEERING, INC. Should be contacted to inspect foundation recommendations for compliance to those set forth. During placement of concrete North County COMPACTION ENGINEERING, INC. And/or a qualified concrete inspector should be present to document construction of foundations. UNCERTAINTY ANP~IMITATIONS It should be noted, foundation inspections on projects located within the county of San Diego jurisdiction may not require inspection by our rum. Therefore, the project owner and/or the general contractor may waive the inspection and assume responsibility to assure that all recommendations presented in this report are incorporated into the construction phase of the project. However, North County COMPACTION ENGINEERING, INC. Cannot assume liability for projects not inspected by our firm. NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-5325 Page 5 In the event foundation excavation and steel placement inspection is required and/or requested, an additional cost of$170.00 will be invoiced to perform the field inspection and prepare a "Final Conformance Letter". Iffoundations are constructed in more than one phase, $120.00 for each additional inspection will be invoiced. It is the responsibility of the owner and/or his representative to carry our recommendations set forth in this report. San Diego County is located in a high risk area with regard to earthquake. Earthquake resistant projects are economically unfeasible. Therefore, damage as a result of earthquake is probable and we assume no liability. We assume the on-site safety of our personnel only. We cannot assume liability of personnel other than our own, It is the responsibility of the owner and contractor to insure construction operations are conducted in a safe manner and in conformance with regulations governed by CAL-OSHA and/or local agencies. If you have any questions, please do not hesitate to contact us. This opportunity to be of service is sincerely appreciated. Respectfully submitted. ~orth County COMPACTION ENGINEERING, INC. ~~ Ronald K. Adams President RKA:kla cc: (3) submitted .~~ , , NORTH COClNlY COMPACTION ENGINEERING, INC. SOIL TESTING PROPOSED DAVIS RESIDENCE 3369 Calle Margarita 01ivenhain, California I :..-1 -- {þ Approx. Scale 1" = 40' N 2'2$'1g- If 516. ~ - - ...., ~ 11 I //~ .:; \ \ I L I ---- I I TEST LOCATION SKETCH . PROJECT No. CE-5325 PLA TE No. ONE NORTH COUNTY COMPACTION ENGINEERING, INC. Test # Date Horizontal Vertical Field Moisture Dry Density Soil Percent of Location Location % Dry Wt. LB Cu. Ft. Type Compaction 1 01122/97 See 332.0 20.0 102.0 II 91.8 2 Plate 334.0 18.9 101.3 11 91.2 3 02104/97 One 328.0 19.7 103.0 1 90,7 4 ,. " 330.0 18.7 108.2 I 95,3 5 327.0 16.7 102.4 I 90,2 6 " 329.0 20.4 102,6 I 90.4 7 331.0 18.8 103.5 I 91.2 8 " 329.0 19.4 105.5 I 93.0 9 02/05/97 330.0 17.3 102.5 1 90.3 10 " " 332.0 16.8 105.1 I 92.6 11 " 331.0 18,2 100.9 n 90.9 12 " " 333.0 16.8 101.7 III 90,3 13 " " 336.0 16,2 105.7 I 93,1 14 02106/97 335.0 13,2 108,8 lil 96.6 15 " . " 337.0 14.6, 109.4 III 97,2 16 " " 335.0 18.1 102.4 III 90.9 17 " 337.0 11.5 103.8 III 92.2 18 " 335.0 15.2 104.4 ill 92.7 19 02111/97 337.5 15,4 106.54 1 93,8 20 " 338.0 16.9 108.8 III 96.6 21 02112197 336.5 16,1 106.3 Ul 94,4 22 " 336.5 16.4 104,0 III 92.4 23 02/13/97 339.0 RFG 14,4 105.8 lil 94.0 24 " 338.0 RFG 12.0 108.6 III 96.4 25 " 338.0 RFG 11.6 107.7 III 95,6 26 " 334.0 RFG 12.0 108.2 III 96.1 REMARKS: RFG = Rough Finish Grade PROJECT NO. CE-532S PLATE NO. 1WO I . . . NORTH COUNTY COMPACTION ENGINEERING, INC. OPTIMUM MOISTURE/MAXIMUM DENSITY SOIL DßSCRIPTION :IYff MAX. DRY DENSITY (LB. CU. FT) Beige Light Gray, Orange Clayey-Sand I Brown Red Silty-clay 11 Light Tan Silty-Sandy-clay 111 113.5 111.0 112.6 EXPANSION POTENTIAL SAMPLE No. CONDmON INITIAL MOISTURE (%) AIR DRY MOISTURE (%) FINAL MOISTURE (%) FINAL DRY DENSITY (PCF) LOAD (PSF) SWELL(%) EXPANSION INDEX n Remold 90% 1~.8 11.0 30.4 101.3 150 10.0 100 PROJECT NO. CE-S32S PLATE NO. mUE OPT. MOISTURE (% DR Y WT) 15.7 14.0 15.6