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Home My WebLink AboutPE 2.85.81; POINSETTIA VILLAGE; ENGINEERING OBSERVATION; 1987-09-14S 3467 Kurtz Street San Diego, California 92110 (619) 224-2911 . S Woodward-Clyde Consultants itdUINEERING p4c September 14, 1987 Revised. September 29, 1987 Project No. 8751264W-EW02 Poinsettia Associates do Holmes and Reynolds Development Company 2398 San Diego Avenue San Diego, California 92110 Attention: Mr. Fred Delany REPORT OF ENGINEERING OBSERVATION OF REGRADING AND. TESTING OF COMPACTED FILL LOTS 7 AND 8. POINSETTIA VILLAGE CARLSBAD, CALIFORNIA Gentlemen: In accordance with your request and' our authorized 'proposal dated July 8, 1987 'and your 'authorization dated 'July 14, 1987, we have provided engineering services in conjunction with the grading at the 'subject site. SCOPE OF WORK Our services include: Providing engineering observation of the grading operation; Performing field density tests' in the, placed and compacted fill; O Performing labortory tests on samples of the material use,d for fill'; and - Providing professional opinions regarding the contractor's general adherence to plans and specifications. SUMMARY OF GENERAL EARTHWORK AND TESTING Site preparation, compaction, and testing were done between July 20, 1987 and September 10, 198. In our opinion, based on our observation and testing, the work performed during that period was in general conformance with the ' Guide Specifications for Site Grading attached to our report entitled "Update Geotechnical Investigation for the Proposed Poinsettia Village, Carlsbad, California," 'dated June 27, 1986 and our letter dated September 4, 1987. Consulting Engineers, Geologists and Environmental Scientists Offices in Other Principal Cities qW d / rp w 12r Poinsettia AssoStes Project No. 8751264W-EW02 Woodward-Clyde Consultants September 14, 1987 Revised September 29, 1987 Page Previous grading of the subject site was completed between May 7 and August 29,'1984. That grading consisted of excavation up to 15 feet near the, eastern site boundary of Lots 7 and 8 and shallow cut at the western boundary. That work is summarized in a report dated February 7, 1985. During this period the surfaces to receive fill were scarified, watered and compacted. and new 1111 was placed over the site. Approximately 2 reet of fill was placed. The maximum depth of fill on the lots is on the order of 6 feet. Field density tests were in accordance with Test Method ASTM D2922-81 (Density of Soil and Soil Aggregate in Place by Nuclear Methods). Maxi- mum dry density and optimum moisture content measurements were made in accordance with Test Method ASTM D1557-78, (Moisture-Density Relations of Soils and Soil-Aggregate Mixtures). The reported tests represent the relative compaction and water content at the locations tested. The observations of construction and field density testing procedures used followed normally accepted procedures which are not exact. The accuracy of the maximum dry density determination (Test Method ASTM D1557-7) is discussed in the 1985 Annual Book of ASTM Standards, Section 4, Volume 04.08 "Soil and Rock; Building Stones". Variations in relative compaction should be expected in lateral and vertical extent. Subject to these precision limitations discussed above, field observations and results of field density tests indicate that the fill has been generally compacted to 90 percent or more of maximum dry density as determined in accordance with Test Methods ASTM D2922-81 and D1557-78.. Our observa- tions were not continuous. We have no knowledge as to the condition of fill not observed or tested during placement. For reference, the approxi- mate 'location of field density tests and the limits of compacted fill have been recorded on a copy of the grading plan. The results of field density tests, expressed as a percent of maximum laboratory dry density (relative compaction), are presented on the attached forms. Laboratory tests were made on samples of the materials used for fill. The tests were performed to evaluate moisture-density relationships, maximum dry density, optimum moisture content, grain size distribution and plasticity characteristics. The results of laboratory tests are attached. SUMMARY OF FINISH GRADE SOIL CONDITIONS Observation and laboratory tests indicate that low expansive fill was placed within 2 feet of rough grade' on both lots noted herein. Underlying the fill formational soils are also considered low expansive. d/rpwl2r Poinsettia Ass•tes Project No. 8751264W-EWO2 September 14, 1987 Revised September 29, 1987 Page 3 Woodward-Clyde Consultants RECOMMENDATIONS Foundations for Structures on Low Expansive Soil We recommend that foundations for single-story or two-story light to medium weight commercial structures placed on low expansive, undisturbed soi, properly compacted fill be designed for a bearing pressure not ex- ceeding 3, UUO psf (dead plus live loads). We recommend that footings be founded at least 18 inches below finished grade, and have a minimum width of 12 inches. In our opinion, this bearing pressure can be increased by no more than one-third for loads that include wind or seismic forces. Steel reinforcing is recommended in concrete footings. Reinforcement recommendations should be obtained from an engineer knowledgeable in concrete structures. Concrete Slabs-On-Grade We recommend that floor slabs be properly designed in accordance with the proposed slab loading. We recommend that the slab thickness be at least 4 inches thick and at least reinforced with steel mesh. An underlay of 2 inches of sand and plastic membrane is recommended whereon moisture sensitive floor coverings are used. Additional Fill and Utility Trenches This report discusses the fill placement observed by personnel from our firm during the periods specified. We recommend that any additional fill placed, as well as backfill placed in utility trenches located within 5 feet of any improvements and deeper than 12 inches, or backfill placed in any trench located 5 feet or more from a building and deeper than 5 feet, be compacted under our observation and tested to verify compliance witn the earthwork specifications for the project. Scheduling Earthwork Observations and Testing services It is our intent to provide prompt, efficient and effective earthwork observation and testing services. To provide such services, we need the cooperation of our clients. Please provide us with lead time. regarding the need for our field services ox at least 48 hours when ever possible. We may not be able to fill requests for services made later than 4 p.m. of the previous evening. Drainage We recommend that positive measures be taken to properly finish grade each lot after structures and other improvements are in place, so that drainage waters from the lots and adjacent properties are directed off the lots and away from foundations, floor slabs, and slope tops. Even when these measures are taken, a shallow ground-water or surface-water condition can and may develop in areas where no such water condition existed prior to d / rp w 12r Poinsettia Asso tes Project No. 8751264W-EW02 Woodward-Clyde Consultants September 14, 1987 Revised September 29, 1987 Page site development; this is particularly true where a substantial increase in surface-water infiltration results from landscape irrigation. If a subsurface moisture condition occurs such , as from landscape irrigation, leaking utilities or other sources, foundation settlements can occur. Exterior Concrete Flatwork' We recommend that contractual arrangements between the builder and the subcontractor constructing concrete patio slabs, sidewalks, driveways and garage slabs hold the subcontractor responsible for proper preparation of the subgrade prior to placing concrete slabs. Our services in connection with this project do not include design of slabs or inspection prior to placing concrete slabs, hence we will not accept any responsibility for performance of exterior or garage concrete slabs. LIMITATIONS The elevations of compaction tests known as finished grade (FG) tests on the attached forms correspond to the elevations shown on Sheet 3 of 5 of the plans entitled "Grading Plan For CT 81-6(B) (Poinsettia Village)", dated December 23, 1985, prepared by Rodney C. Imming. Elevations and locations used in this report were based on field surveys done by others. The soil conditions described in this report are based on observations and periodic testing. This office should be notified of any indications that soil conditions are not as described herein. We will examine foundation excava- tions for each lot if we are requested to do so. For this report, rough grade is defined as that grade set in the field by the grade checker from reference stakes established by the surveyor, and represents rough grade at the time we were observing the grading opera- tion. Likewise, the indicated depths of undercutting of low expansive soil and/or depths of placement of soil were based on the measurements made by and grades set by the contractor's grade checker. rhe conclusions and opinions drawn from the test results and site observations apply only to our work with respect to grading, and repre- sent conditions at the date of our final site visit on September 10, 1987. We will accept no responsibility for any subsequent changes made to this site by others, or by uncontrolled action of water, or by failure of others to properly repair damages by uncontrolled action of water. We cannot provide advice, opinions or conclusions relative to site preparation (clearing, grubbing, canyon clean-out, and installation of canyon sub- drains etc.) which we have not observed. d / rp wi 2 r Poinsettia AssoSes Project No. 8751264W-EW02 September 14, 1987 Revised September 29, 1987 Page 5 S Woodward-Clyde Consultants Professional judgments represented in this report are based partly on our- evaluations of the technical information gathered, partly on our under- standing of the proposed construction, and partly on our general ex- perience in the geotechnical field. Our engineering work and judgments rendered meet or exceed the standard care of our profession at this time. We do not guarantee the performance of the project in any respect. Very truly yours, WOODWARD-CLYDE CONSULTANTS ESS P. Richard P. While R.E. 21992 21992 RPw/rlg Exp. cm Attachments OF C d / rp w 12r Compaction Test Results Job Name Poinsettia Village Date Reported 9/14/87 Job Number 8751264W-EW02 (Fill) Dates covered July 20, 1987 through September 10, 1987 . Page 1 Of 4 TEST DATE NUMBER RETEST OF LOCATION FIELD MOIST. ELEVATION CONTENT OF TEST ¼ DRY WT. FIELD DENSITY PCF LAB SAMPLE NO. LAB DENSITY PCF ADJ. MOIST. . RELATIVE FIELD ROCK ADJ. LAB CONTENT COMPACTION ¼ OF ¼ DRY WT. DENS. PCF ¼ DRY WI. LAB. DENS. Jul 20 35 Lot 8 68' 9.2 119.0 3 126.5 . 94 1987 36 Lot 7 67' 9.2 121.7 3 126.5 92 37 Lot 7 . 66' 8.9 119.3 3 126.5 . . 94 Jul 21 38 Lot 8 70' 9.0 120.6 3 126.5 . .95 1987 39 Lot 7 69'. 8.4 120.3 3 126.5 . 95 40 Lot 7 68' .7.9 119.4 3 126.5 . 94 41 Lot 8 70' 11.8 118.1 3 126.5 93 - 42 Lot 8 71' 7.7 121.2 3 126.5 . 95 43 Lot 8 72' 10.5 117.3 3 126.5 . .92 Jul 29 44 Parking Lot W. Side . 1987 Bldg. G FIG 66.9' . 6.2 126.1 4 131.0 96 45 Parking Lot W. Side . Bldg. F FIG 66.5' 11.4 123.3 4 131.0 . . 94 46 Parking Lot W. Side Bldg. F FIG 67.3' 7.2 . 127.6 4 131.0 . 97 47 Parking Lot W. Side . . . 48 Bldg. E Parking Lot W. FIG Side 67.3' 8.1 127.0 4 131.0 . . . . . 96 Bldg. C FIG 67.1' 9.3 125.8 4 131.0 96 49 Parking Lot W. Side Bldg. C FIG 67.0' 7.5 121.5 4 131.0 . 9.2 Jul 30 50 Parking Lot W. Side . 1987 Bldg. B . FIG 67.1' 4.5 117.4 3 126.5 . 92 51 Parking Lot W. Side . . Bldg. C FIG 66.2' 9.2 120.0 4 131.0 . 91 52 Parking Lot W. Side . Bldg. C FIG 66.0' 6.8 121.8 4 131.0 93 Woodward-Clyde Consultants Mv COmpaction Test Results Job Name Poinsettia Village Date Reported 9 /14/87 Job Number 8751264W-EW02 (Fill) Dates Covered July 20, 1987 through September 10, 1987 Page of TEST RETEST DATE NUMBER OF Jul 30 53 1987 54 55 56 57 58 59 LOCATION FIELD MOIST. ADJ. MOIST. RELATIVE ELEVATION CONTENT FIELD LAB LAO FIELD ROCK ADJ. LAB CONTENT COMPACTION % OF OF TEST % DRY WY. DENSITY PCF SAMPLE NO. DENSITY PCF T'. DRY WT, DENS. PCF V. DRY WI. LAB DENS Parking Lot W. Side Bldg. F I FIG 66.4' 7.1 122.0 4 131.0 93 Parking Lot W. Side Bldg. F FIG 66.4' 6.1 116.7 3 126.5 . 92 Parking Lot W. Side Bldg. C FIG 65.4' 5.6 118.1 4 131.0 90 Parking Lot W. Side Bldg. F FIG 66.0' 6.4 124.0 4 131.0 . 94 Parking Lot W. Side Bldg. E FIG 65.4' 7.5 120.8 4 131.0 92 Parking Lot W. Side Bldg. C FIG 66.0' 6.9 123.1 4 131.0 94 Parking Lot 1st Entrance off Avenida Encinas FIG 66.0' 8.5 117.0 3 126.5 92 Lot 12 Driveway Off Avenue Encinas FIG 65.7' 6.3 111.4 4 131.0 85 Parking Lot S. of . . Bldg. G FIG 65.0' 6.5 123.7 4 131.0 . 94 Future Pad 6 FIG 66.4' 9.1 115.8 3 126.5 91 Future Pad 6 FG 66.4' 9.6 114.7 3 126.5 90 Lot 8 72' 8.9 114.6 3 126.5 . 90 Lot 8 71' 8.3 118.7 4 131.0 90 Lot 8 71' 8.5 119.7 4 131.0 91 Bldg. A . 59' 12.5 115.1 5 127.0 . . 90 Parking Lot N. Bldg. . A 59' 12.0 115.1 5 126.0 90 Woodward-Clyde Consultants Jul 31 60 1987 61 62 63 Aug 20 64 1987 65 66 Aug 26 67 1987 68 Compaction Test Results V Job Name Poinsettia Village Date Reported 9/14/87 . Job Number . 8751264W-EW02 (Fill) . Dates Covered July 20, 1987 through September 10, 1987 Page 3 Of 4 V TEST DATE NUMBER RETEST OF LOCATION ELEVATION OF TEST FIELD MOIST. CONTENT ¼ DRY WT. FIELD DENSITY PCF LAB SAMPLE NO. ADJ. MOIST. 1.58 FIELD ROCK ADJ. LAB CONTENT DENSITY PCF ¼ DRY WI. DENS. PCF ¼ DRY WI. . . RELATIVE COMPACTION ¼ OF LAB DENS Aug 26 69 Parking Lot S. Bldg. 1987 . A 60' 11.2 115.6 5 127.0 91 70 Parking Lot N. Bldg. • A V 61' 10.3 113.9 4 131.0 . 86 71 . Bldg. A 61' 10.3 117.5 4 131.0 89 72 71 Bldg. A 61' 9.0 119.2 4 . 131.0 91 73 70 Parking Lot N. of . Bldg. A 61' 10.8 121.8 4 131.0 93 74 Parking Lot S. of . Bldg. 'A 63' 9.9 118.3 4 131.0 . . .90 75 Bldg. A 63' 10.6 114.3 3 126.5 . 90 77 Parking Lot S. of V Bldg. A 64' 10.0 115.3 3 126.5 . 91 78 . Parking Lot N. of Bldg. A 64' 11.6 116.5 3 126.5 V 92 79 Bldg. A . 64' 11.2 117.2 3 126.5 . 92 80 Parking Lot N. of Bldg. A 64' 8.5 118.5 4 131.0 . 90 81 Parking Lot S. of . Bldg. A 65' 9.9 116.0 3 126.5 V 91 82 Bldg. A 65' 14.0 11.4.1 3 126.5 . 90 Sep 09 87 Lot 8, W. End FIG 68' 8.5 129.3 4 131.0 98 1987 88 Lot 8, Middle FIG 70' 9.1 . 124.2 4 131.0 . V . . 94 89 Lot 8, E. End FIG 72' 6.8 107.3 4 131.0 . 81 90 . Lot 7, E. Corner FIG 70.5' 8.5 122.7 4 131.0 . 93 91 Lot 7, Middle FIG 68.5' 6.6 121.8 4 131.0 93 92 Lot 7, W. End FIG 66.5' 10.2 114.1 4 131.0 . 87 Woodward-Clyde Consultants mW V Compaction Test Results Job Name Poinsettia Village S Date Reported 9/14/87 Job Number 8751264W—EW02 (Fill) Dates Covered July 20, 1987 through September 10, 1987 Page 4 Of 4 TEST DATE NUMBER RETEST OF LOCATION ELEVATION OF TEST FIELD MOIST. CONTENT V. DRY WT. FIELD DENSITY PCF LAB SAMPLE NO. LAB DENSITY PCF ADJ. MOIST. FIELD ROCK ADJ. LAB CONTENT % DRY WT. DENS. PCF V. DRY WT. RELATIVE COMPACTION V. OF LAB. DENS. Sep 10 93 92 Lot 7, W. End FG 66.5' 10.0 117.8 4 131.0 5 90 1987 94 89 Lot 8, E. End FIG 72' 7.9 124.6 4 131.0 . 95 Sep 24 95 60 Driveway, Lot 12 65.7' 6.4 117.5 4 131.0 5 . 90. Woodward. Clyde Consultants 0 120 SAMPLE LOCATION 3 BLDG. C 4 PKG. LOT, W. SIDE OF BLDG. MECHANICAL/MOIST 40 LABORATORY CQMPACTION TEST METHOD: 3—ASTM—D155778 A PLASTICITY CHARACTERISTICS 3 4 5 Liquid Limit, % 24 Plasticity Index, % NP NP 14 Classification by Unified Soil Classification System SM SM sc (COBBLES REfL SAND j SILT & CLAY] 0 100 z 80 150 140 ZERO AIR VOIDS CURVES —2.80 SG - 2.70 SG —2.6OSG 2.50 SG 60 I— uj 40 0 Cr o. 20 01 l III liii liii Ill I J 1000 100 10 1.0 0.1 0.01 0.001 GRAIN SIZE, mm MECHANICAL ANALYSIS 130 DIRECT SHEAR TEST DATA Dry Density, pcf Initial Water Content, % Final Water Content, % Apparent _Cohesion, _psf Apparent Friction Angle, degrees SWELL TEST DATA Initial _Dry _Density, _pcf Initial Water Content, % Final _Dry _Density, _pcf Final Water Content, % Load, psf Swell, percent #5—LOCATION—SEWER & STORM DRAIN TR.B.F. 03 04 s Maximum Dry Density, pcf 126.5 131.0 127.0 - - - Optimum Moisture Content,% 9.51 8.0 9.0 80 I TMOISTURE CONTENT, - - 10 20 30 I ARnPATflRV COMPACTION TEST ... ...............- SAMPLE #4—ASTM—D 1557-7E 1 FILL SUITABILITY TESTS I POINSETTIA VILLAGE [RAWNBY:cb _ CHECKED BY:'l4V[ PROJECT NO: 8751264w_Ewo2I_ DATE: 9/11/8 7 _ FIGURE NO: 1 WOODWARD-CLYDE CONSULTANTS