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Home My WebLink About; Poinsettia Park Soccer Field Geotechnical Recs; Poinsettia Park Soccer Field Geotechnical Recommendations; 2002-05-17GEOTECHNICAL ENGINEERING RECOMMENDATIONS POINSETTIA PARK SOCCER FIELD Hidden Valley Road Carlsbad, California Prepared for: Mr. Duane Soileau City of Carlsbad - Inspection Division 1635 Faraday Avenue Carlsbad, Caliornia Prepared by: Testing Engineers - San Diego, Inc. 7895 Convoy Court, Suit 18 San Diego, CaUfornia 92111 ProjectNo. 2002-0315 May 17, 2002 Testing Engineers- San Diego, Inc. Established 1946 City of Carlsbad May 16, 2002 Inspection Division Project No. 2002-0315 Attn: Mr. Duane Soileau Telephone; 760-602-2780 1635 Faraday Avenue Fax:760-438-4178 Carlsbad, CA 92008 Subject: Geotecimical Engineering Recommendation Project: Poinsettia Park Soccer Field Hidden Valley Road Carlsbad, CA Reference: "Precise Grading Plan for Poinsettia Community Park", City of Carlsbad, Engineering Department. Dear Mr. Soileau: This letter presents geotechnical engineering recommendations prepared by Testing Engineers-San Diego, Inc. for the soccer field subgrade preparation. Review of the information provided, which includes the referenced graduig plan, indicates that the field is to be covered with artificial turf. We understand that the new artificial turf needs be placed over a uniform, moisture conditioned and compacted subgrade. Site Description The subject soccer field is located at the northwest comer of the Poinsettia Community Park, which in turn is located west of Hidden Valley Road and Plum Tree Road intersection in Carlsbad, Califomia. A Vicinity Map is presented on Plate 1. The field encompasses a previously graded lot, approximately 320 by 400 feet. The lot gently slopes towards the west; it is bordered by a cut slope to the east and by a fill slope to the west and southwest. Subsurface Exploration In order to obtain information regarding the existing soils conditions, in-place density tests were performed in five locations within the soccer field as indicated on the Site Plan, Plate 2. The density tests were performed on the subgrade soil, after the existing natural grass and the heavy-root zone were removed. In addition, hand-auger borings were performed at the same five locations as the density tests to a maximum depth of 2.5 feet. Generally, two different soil conditions were found. Bay Point Formation sandstone was encountered at the SCI and SC5 locations, to the total depth of the boring. The orange/reddish brown sandstone was moist to wet, dense to very dense, and weakly cemented. Testing Engineers - San Diego, Inc., 7895 Convoy Court, SuitelS San Diego, CA. 92111 [858] 7 1 5-5800 Fax [858] 715-5810 Undocumented Fill was encountered at the SC2 through SC4 locations, to the total depth of the boring. The fill encountered consisted of a moist to wet, medium dense to dense, silty sand with a trace of clay. It appears that the soil used as fill was derived from the cut areas, during the original grading. Appendix A contains logs of the subsurface exploration. The in-place density tests were performed in accordance with ASTM D1556 test method. Two of the density tests were in the cut area of the field, and the other three on the fill portion of it. The densities varied from 109.3 to 123.4 pounds per cubic foot and the in-place moisture varied from 8.3 to 12.0 percent. The following table describes the density test results, including the location and relative compaction. Density Test Location SCI SC2 SC3 SC4 SC5 Type of Soil Formation Fill Fill Fill Formation Wet Density (pcf) 126.6 119.5 130.7 123.7 138.2 Dry Density (pcf) 116.9 109.3 120.2 113.0 123.4 Moisture Content (%) 8.3 9.3 8.7 9.4 12.0 Maximum Density (pcf) 130.0 128.0 128.0 128.0 130.0 Optimum Moisture (%) 9.0 9.0 9.0 9.0 9.0 Percent Compaction (%) 90 85 94 88 95 Laboratory Testing Laboratory maximum density tests (ASTM D1557) were performed on two samples, one represents the fomiational sandstone and the other represents the fill material. The formational sandstone has a maximum density and optimum moisture content of 130.0 pcf and 9.0 percent, respectively. The fill material has a maximum density and optimum moisture content of 128.0 pcf and 9.0 percent, respectively. The test results are contained in Appendix B. Conclusions and Recommendations Based on the test results, the observations of the hand-auger borings and TESD's experience with similar soil conditions, it is concluded that the existing condition of the soil within the, soccer field is stable. However, the upper one foot of soil has a variable density and moisture content. Therefore, the observed soil conditions indicate that the proposed soccer field turf subgrade will likely consist of varying supporting conditions. TESD recommends that the upper 8 inches of subgrade be scarified, uniformly moisture conditioned and recompacted to 90 percent relative compaction in accordance with ASTM D1557 test method. The scarification should be performed so that it produces a uniform lift with the required density and moisture content. This will create a more uniform supporting condition for the new artificial turf. TESD. Inc. * Poinsettia Park - Soccer Field* 2002-0315 * May . 2002 2 of 3 Limits of Investigation Our investigation was performed using the skill and degree of care ordinarily exercised, under similar circumstances, by reputable geotechnical engineers and geologists practicing in this or sunilar localities. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. This report is prepared for the sole use of our client and may not be assigned to others without the written consent of the client and Testmg Engineers-San Diego. The samples taken and used for testiag, and the observations made, are believed representative of site conditions; however, soil and geologic conditions can vary significantly between borings and surface exposures. As in most major projects, conditions revealed by constmction excavations may vary with preliminary findings. If this occurs, a representative of Testing Engineers-San Diego must evaluate the changed conditions and designs adjusted as required or altemate designs recommended. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the project architect and engineer. The necessary steps should be taken to see that the contractor and subcontractors carry out such recommendations in the field. The findings of this report are valid as of this present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur from legislation or the broadening of knowledge. Accordingly, the findmgs of this report may be invalidated wholly or partially by changes outside of our control. Therefore, this report is subject to review and should be updated after a period of three years. Additional Services The review of plans and specifications, field observations and testing under TESD's direction is an integral part of the recommendations made in this report. If Testing Engineers-San Diego is not retained for these services, the client agrees to assume our responsibility for any potential claims that may arise during constmction. Observation and testing are additional services, which are provided by TESD, and should be budgeted withm the cost of development. Testing Engineers-San Diego, Inc. appreciates the opportunity to provide this geotechnical engineering service for your project. Please contact this office if you have any questions_CQii£OTiing the content of this letter. RespectfiiUy submitted. Testing Engineers - San Diego, Inc. Carlos E. Afcero Staff Engineer Enck Aldrich, RCE 578 Geotechnical Engineer TESD. Inc. * Poinsettia Park - Soccer Field* 2002-0315 * May . 2002 3 of 3 PLATES • u •%- -JTSO ft: 1 apo tJl=.A '.^.ij t-opyiigilit E>el_oim« Yaamoum, ME O^io^e, Scale: ^ : 1:2^00 oetail; Testing Engineers - San Diego, Inc. 7895 Convoy Court, Suite 18 San Diego, CA 92111 Tel: (858) 715-5800 Fax: (858) 715-5810 Vicinity IVIAP - Plate 1 Polnsetia Park -Soccer Field Carlsbad, California 2002-0315 IVlay, 2002 I APPENDIX A FIELD EXPLORATION LOGS GENERAL NOTES SAMPLE IDENTIFICATION The Unified Soil Classification System is used to identify the soil unless otherwise noted. SOIL PROPERTY SYMBOLS N: Standard "N" penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D. split-spoon. Qu: Unconfmed compressive strength, tsf. Qp: Penetrometer value, unconfmed compressive strength, tsf. Mc: Water content, %. LL: Liquid limit, %. PI: Plasticity index, %. DD: Natural dry density, PCF. V : Apparent groundwater level at time noted after completion. DRILLING AND SAMPLING SYMBOLS CAL: Modified Califomia Sampler - 2 5/8" I.D., 3.0" O.D., except where noted. SS: Split-Spoon - 1 3/8" I.D., 2" O.D., except where noted. ST: Shelby Tube - 3" O.D., except where noted. AU: Auger Sample. DB: Diamond Bit. CB: Carbide Bit. WS: Washed Sample. RELATIVE DENSITY AND CONSISTENCY CLASSIHCATION TERM (NON-COHESIVE SOILS) STANDARD PENETRATION RESISTANCE (SPT) Very Loose 0 to 4 Loose 4 to 10 Medium Dense 11 to 30 Dense 31 to 50 Very Dense Over 50 TERM (COHESIVE SOILS) SPT QU - (TSF) Very Soft 0 to 2 0 -0.25 Soft 2 to 4 0.25-0.50 , Medium Stiff 4 to 8 0.50- 1.00 Stiff 8 to 16 1.00-2.00 Very Stiff 16 to 32 2.00 - 4.00 Hard Over 32 4.00+ PARTICLE SIZE Boulders 12 in. 4- Coarse Sand 5mm-0.6mm Silt 0.074 mm-0.005mm Cobbles 12 in -3.in Medium Sand 0.6mm-0.2mm Clay < 0.005mm Gravel 3 in -5mm Fine Sand 0.2mm-0.074mm Testing Engineers - San Diego, Inc. 7895 Convoy Court, Suite 18 San Diego, CA 920111 Tel (858) 715-5800 Fax (858) 715-5810 LOG OF HAND-AUGER BORING PROJECT NAME: Poinsettia Park-Soccer Field PROJECTNO: ^00^-0315 DATE OBSERVED: LOGGED BY; 5/3/02 CEA GROUND ELEVATION: METHOD OF EXCAVATION: Hand Auger N/A LOCATION: See Map DEPTH (INCHES CLASS N UNO SAMPLE BULK SAMPLE MOIST. CONT. (%) DD BORING NO.: SC-1 DESCRIPTION SOIL TEST Grass turf, heavy-root zone 2-inch thick - SM 8.3 116.9 Sandstone (Bay Point Formation) Orange/reddish brown, moist, dense to very dense, weakly cemented M.O. = 130.0 pcf O.M.= 9.0% 10 — 20 — Terminated at 2 feet 2 inches 30 — No Groundwater was encountered LOGGED BY: CEA GROUND ELEVATION: N/A LOCATION: See Map BORING NO.: SC-2 Grass turf, heavy-root zone 2-inch thick SM 9.3 109.3 Silty SAND with trace clay (Undocumented Fill) M.D.= 128.0 pcf Orange/brown, moist, dense, mottled with brown/olive gray clay trace of granite gravel (3/4-inch) O.M.=9.0% 10 — • 20 — Terminated at 2 feet 2 inches 30 — No groundwater encountered - Test Pit Logs , Testing Engineers - San Diego, Inc. 7895 Convoy Court, Suite 18 San Diego, CA 920111 Tel (858) 715-5800 Fax (858) 715-5810 LOG OF HAND-AUGER BORING PROJECT NAME: Poinsettia Park-Soccer Field PROJECTNO: 2002-U315 DATE OBSERVED: 5/3/02 METHOD OF EXCAVATION: Hsnd Auger LOGGED BY: CEA GROUND ELEVATION: ' N/A LOCATION: See Map DEPTH UND BULK MOIST. BORING NO.: SC-3 (INCHES CLASS N SAMPLE SAMPLE CONT. (%) DD DESCRIPTION SOIL TEST Grass turf, heavy-root zone 2-inch thick SM 8.7 120.2 Silty SAND with trace clay (Undocumented Fill) Orange/brown,damp to moist, dense, mottled with brown/olive gray clay, trace of granite gravel (3/4-inch) 10 — 20 — 30 — Terminated at 2 feet 4 inches _ No Groundwater was encountered LOGGED BY: CEA GROUND ELEVATION: N/A LOCATION: See Map BORING NO.: SC-4 Grass turf, heavy-root zone 2-inch thick SM 9.4 113.0 Silty SAND with trace clay (Undocumented Fill) Orange/brown, moist, dense, mottled with brown/olive gray clay trace of granite gravel (3/4-inch) 10 — 23 — Terminated at 2 feet No groundwater encountered 30 — -- Test Pit Logs Testing Engineers - San Diego, Inc. 7895 Convoy Court, Suite 18 San Diego, CA 920111 Tel (858) 715-5800 Fax (858) 715-5810 LOG OF HAND-AUGER BORING PROJECT NAME: Poinsettia Park- Soccer Field PROJECTNO: 2U02-U;J1& DATE OBSERVED: 5/3/02 METHOD OF EXCAVATION: Hand Augep LOGGED BY: CEA GROUND ELEVATION: N/A LOCATION: ' Sse Map DEPTH UND BULK MOIST. BORING NO.: SC-5 (INCHES CLASS N SAMPLE SAMPLE CONT. (%) DO DESCRIPTION SOIL TEST Turf, heavy-root zone 2-inch thick SM 12.0 123.4 Sandstone (Bay Point Formation) Orange/reddish brown, moist to wet, dense to very dense 10 — 20 — Terminated at 2 feet 2 inches 30 — No Groundwater was encountered LOGGED BY: CEA GROUND ELEVATION: N/A LOCATION: See Map BORING NO.: 10 — 20 — ; 30 — I I Test Pit Logs APPENDIX B LABORATORY TEST RESULTS COMPACTION TEST REPORT Curve No.: 1 ProjectNo.: 02-0315 Project: Poinsettia Park Soccer Field - Geo T&I Location: FILL MATERIAL Elev./Depth: 24"-32" Remarks: TESD NO. 4515 Date: 5/3/02 MATERIAL DESCRIPTION Description: BROWN CLAYEY SAND Classifications - USCS: Nat. Moist. = Liquid Limit = % > No.4 = % AASHTO: Sp.G. = Plasticity Index = % < No.200 = 140 130 120 Q. I lU >^ '</) c <u TD a 100 90 80 70 TEST RESULTS Maximum di7 density = 128 pcf Optimum moisture = 9 % Test specification: k ASTM D 1557-91 Procedure A Modified -A Test specification: k ASTM D 1557-91 Procedure A Modified -A 100% SATURATION CURVES FOR SPEC. GRAV. EQUAL TO: 100% SATURATION CURVES FOR SPEC. GRAV. EQUAL TO: 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 1 ' I i i i i 1 i 10 15 20 25 Water content, % 30 -TESTING ENGINEERS- 35 Plate 40 COMPACTION TEST REPORT Curve No.: 2 ProjectNo.: 02-0315 Project: Poinsettia Park Soccer Field - Geo T&I Location: FORMATION SANDSTONE Elev./Depth: 24"-26" Remarks: TESD NO. 4516 MATERIAL DESCRIPTION Description: DARK ORANGE-LIGHT BROWN CLAYEY SAND Date: 5/3/02 Classifications Nat. Moist. = Liquid Limit = %>No.4= % USCS: AASHTO: Sp.G. = Plasticity Index = % < No.200 = TEST RESULTS Maximum dry density = 130 pcf Optimum moisture = 9 % 140 130 120 CL C CD •D Q 100 90 80 70 \ Test specification: v,^ ASTM D 1557-91 Procedure A Modified Test specification: v,^ ASTM D 1557-91 Procedure A Modified — — — — J / / 100% SATURATION CURVES 100% SATURATION CURVES hUK bKbC. UKAV. bUUAL 1 U! 2.8 2.7 2.6 2.8 2.7 2.6 2.8 2.7 2.6 - 2.8 2.7 2.6 s -— — — -— — — — —_ 1 i 10 15 20 25 Water content,. % -TESTING ENGINEERS 30 35 Plate 40