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Home My WebLink About3303; Agua Hedionda Sewage Pump Station; Cannon Road - Golf Cart Undercrossing; 1995-04-26c 04/26/1995 16M4 LEIGHTON-SON DIEGO **** 6192920771 P.02 LEIGHTON AND ASSOCIATES, INC Project No. 4930489-09 To: Carltas Company 5600 Aveokla Encinas, Suite 100 Carlsbad, California 92008-4452 Attention: Mr. Chris Calkins Subject: Geotechnical Investigation, Proposed Golf Cart Undercrossing, Cannon Road, Carlsbad, California In accordance with your request, we have performed an additional limited geotechnical investigation at the site of the proposed golf cart undercrossing beneath Cannon Road in Carlsbad, California. The undercrossing will be located at approximately Station No. 27+00 of Cannon Road and will be installed as part of the Phase I development of CarUbad Ranch. Ldghton and Associates (Leighton) has previously performed a geotechnical investigation for both this project and the Gemological Institute of America. We have reviewed the results of our previous reports and the proposed plans as part of this study. In addition, we have met with representatives of Contech regarding their products. Proposed Undercrossing The proposed undercrossing will consist of an aluminum structural plate undercrocsing with • width of 15 feet 4 inches, a height of 10 feet and a length of ±264 feet with a thickness of 0.125 inches. The arch will be provided with cover of approximately 7 to 10 feet of compacted soil backfill The base of the structure will be at an approximate elevation of ±120 feet It is proposed to install the structural plate undercrossing in an open excavation and place compacted backfill to the design grades. A single plate arch with concrete footing is also acceptable. Site Investigation In order to evaluate the site conditions, an exploratory boring was drilled, logged and sampled in the vicinity of the proposed undercrossing. This boring had a total depth of 61 feet and was hm>kff1tfl on completion. The boring log is attached as Appendix B. The boring location is indicated on the attached Figure 1, Boring Location Map. 3934 MURPHY CANYON ROAQ SUITE B205, SAN DIEGQ CALIFORNIA 92123 (619) 292-8030 • (800) 447-2626 IAX (619) 292-0771 c c 04/26/1995 1S:45 LEIGHTON-SflN DIEGO **** 6192920771 P. 03 • 49304894)9 Geologic Conditions As observed in this boring (and others on the Carlsbad Ranch), the area is underlain by dense Terrace deposits. These soils consist of dean to silty sands with minor gravels. No ground water was encountered at the time of our investigation to the total depth explored, which was ±10 feet below the bottom of the proposed structure. The base of the boring encountered sandy sofls of the underlying Santiago Formation. The Santiago Formation is not anticipated to be encountered during site construction because of its depth. Representative samples of the soils encountered were obtained for laboratory testing. A sample obtained at approximately midheight of the structure was tested to evaluate the chemical characteristics of the onsite soils. For soil bearing values, the soils were judged to be similar to those previously tested during previous investigations of the Carlsbad Ranch, The chemical characteristics of the soils are as follows: Samle B-3 @ 4' pH-8.2 Soluble Sulfate Content - <0.005% (negligible per UBC 1994) Minimum Resistivity • 30,000 ohm-cm (very low corrosion potential) In our opinion , the site is suitable to receive the proposed improvements provided the results of this report, project plans, and manufacturer's specifications are adhered to. The values obtained (as pan of our laboratory tests) are within acceptable range fat backfill toils as stated in the brochure provided by the manufacturer of the Aluminum Structural Plate (Cbntech, 1991). We recommend, however, that the manufacturer review the results of this testing to verify that the chemical characteristics are within acceptable ranges. The onsite soils will provide a suitable foundation for the proposed structure. For design purposes, a soil bearing value of 3,000 pounds per square foot may be utilized assuming 1/2-inch of settlement For backfill, the onsite granular soils may be utilized. All backfill should be compacted to a minimum of 95 percent of the soUs maximum dry density. Backfill adjacent to the structure should be compacted with light weight compaction equipment All backfill should be placed above the soils optimum moisture content Backfill soils should be tested to verify conformance with the manufacturer's specifications regarding chemical characteristics. 2- itnmo»»m,Anocum,mc. C 04/26/1995 16=45 LEIGHTON-SflN DIEGO **** 6192920771 P. 04 4930489-09 If utility trenches are proposed over the top of the arch, we recommend that the trenches be backfilled with a lean (1 sack) concrete shiny mix within 5 feet of the top of the arch. The purpose of the slurry would be to avoid the use of heavy construction equipment on top of the arch. Above the S foot zone, conventional soil backfill may be utilized. Some zones of relative cobesionless soils may be encountered during excavation. Therefore, the stability of temporary slopes should be evaluated during construction by the geotecbnfcal consultant. All slopes should be constructed in accordance with OSHA guidelines, Representatives of Contech stated that an equivalent aluminum corrosion rate of 0.5 mil per year may be utilized (Army Corps of Engineers Study). This is roughly equivalent to a time to perforation of 250 years for an aluminum thickness of 0.125 inches. Approximately 2.0 feet of backfill is to be placed inside the undercrossing to provide a pavement subgrade. The backfill soils should consist of granular onsite soils. In order to avoid an accumulation of water, we recommend a subdrain be installed at the low point of the structure. The subdrain should consist of a ^'"fam™ of 1 cubic foot of clean 3/4-inch gravel wrapped in Mirafi 140N geofabric or equivalent and outlet into a stormdrain or some other collective drainage system. As an alternative, a linear slotted drain may be used at both entrances to the tunnel to intercept surface water. If you have any questions regarding our report, please contact this office. We appreciate this opportunity to be of service. Respectfully submitted, LHOHTON AND ASSOCIATES, INC Michael R. Stewart, CEO 1349 (Exp. 12/31/95) Joseph G. Franzone, RCE 39552 Director of Geology Director of Engineering MRS/TGF/kr Attachments: Figure 1 - Boring Location Map Appendix A - References Appendix B - Boring Logs Appendix C • Laboratory Test Results Distribution: (2) Addressee (4) Harrison Company Attention: Mr. Steve Harrison (2) City of Carlsbad Engineering Department Attention: Ms. Sherri Howard 04/26/1995 16:46 LEIGHTON-SAN DIEGO ****6192920771 P.05 c SEE MNHNC DM) Mmownci«iIMS MO OP*. « SHffT 4 Approxfenat* location of wptofatory boring showing total ctepth -N- Ba«e MM: adaottd from Qradlng Plvtt for Carlsbad Ranch, Phase 1 - Lots 5 & 6, ahoat 8of 8 by Oty ofCariabad Enginwfing Department, scab 1" = 40'. dated 3/95 1 BORING LOCATION MAP CARLSBAD RANCH CARLSBAD, CALIFORNIA Project No. 493QABft-Qft Scale Engr./GeoL Drafted By KBC Date 4/26/fl^ c 04/26/1995 16:47 LEIGHTON-SflN DIEGO **** 6192920771 P.06 4930489-09 APPENDIX A Contech Construction Products, Inc., 1991, Manufacturers Brochure-Aluminum Structural Plate. Lcighton and Associates, Inc., 1993, Preliminary Geotechnical Investigation, Units I and n, Lots 1 through 7, Carlsbad Ranch, Phase 1, Carlsbad, California, Project No. 4920489-01, dated July 22,1993. , 1995, Supplemental Geotechnical Investigation, Proposed Oemological Institute of America, Carlsbad, California, Project No. 494071342, dated April 25,1995. O'Day Consultants, 1995, Grading Plans for Carlsbad Ranch Phase 1, Lots 5 and 6, Sheet 8 of 8, dated April 19,1995 ^____ tfW«mWMD400CMl!& SVC 04/26/1995 16:47 LEIGHTON-SflN DIEGO **** 6192920771 P.07 _£OTECHNICAL BORING LOG »-1 4-2145 C»ri»lmd lUnch/Ptmae 1 - Lota 5 and 6 Sheet _ 1 of 3 Project No. 49304M.IM Date Project Drilling Co. Bar«'» Prilling Service Type of Rig HonowStem Aamr Hole Diameter 6 to. Drive Weight 140 panada Drop 30 in Elevation Top of Hole +/- 170 ft. Ref. or Datum ----- r 4- Hjj^^ III 170- 165- j"^!i o^ - 5 — U F i « • • • . . • - . ' 1 & » Iw • • aZfaa. 71+• J/s«»• j31h **.uX!:ss*$8 *>i I ClassU.S.C.S.)<x~ SP-SM GEOTECHNICAL DESCRIPTION Loeeed Bv SCB Sampled By SCB @ 0': IWonmin ind black, medium dente to dense, dirtily mobi, fine tomedium iflty SAND • @ 5': Stme M •bow, und becoming more tan md black in color c 160 155 IO-H IS— ISO 20H 145 C105 A( 11/77)LEIGHTON & ASSOCIATES UKMmM/u0/usoa*m, me Date 04/26/1995 16:48 LEIGHTON-SflN DIEGO **** 6192920771 P.08 ^EOTECHNICAL BORING LOG u-1 4-21-95 Sheet 1 of 3 Project No. _Carlsbad Ranch/Phase 1 - Loto 5 and <S BMW'S Drilling Service Drive Weight Drop J0_ln.Elevation Top of Hole +/- 170 ft. Ref. or Datum Meaa SM Lerd GEOTECHNICAL DESCRIPTION TERRArR nppnsrr^ ^) rtmilnuml @ 30': Tm-btaeK. Heine, moi«, futy, medium to come SAND ! Tin-grtjr, dene, d*mp to moiit, mwllum to covne mvel SAND LEIGHTON & ASSOCIATES 04/26/1995 16=49 LEIGHTON-SfiN DIEGO **** 6192920771 P.11 viEOTECHNICAL BORING LOG B-1 c Date Proje Drill Hole Elevt .2s"'ui 110 105 100 95 90 85 4-21-9S Sheet _3 of 3 i» CmHubadRaoch/Phasf !-Lot«5aDd6 Protect No. 493048941 ngCo Dlam< ition T 11 <o — mm M* 65 — ^ mm; 70— 75— 80— 85 — Oft— Banw't DrilUnc Service TVpe of R it Holtow£teni Anoer iter 6 in. op of Hole +/- 170 ft o P Lti-- 1 1 1 Drive Welg Ref. or Dat Dry OansituCpcf) |MoistureContant OO |it 140nonndi r>mp ^i in am Main Set Level • ^^ — * 5§ GEOTECHNICAL DESCRIPTION Lonacd Bv SCB Sampled By SCB \@W: W«»therwJ ' , SAN11AGO FQRMATIDN (OK)\Whlie, light green, mow, dense, fiiw to coane SAND ' Tots! Depth - 61 Feet No Ground Water Encountered at Time of Drilling Hole Bickniled on April 21, 1995 Ll&B _ - ^A<11/77, LEIGHTON & ASSOCIATES •^•^••Mf"' 04/26/1995 16=50 LEIGHTON-SAN DIEGO ****6192920771 P.12 4930489-09 c APPENDIX C Laboratory Testint Procedures and Test Results Resistivity and pH Tests; Minimum resistivity and pH tests were performed in general accordance with California Test Method 643. The results are presented in the table below; Sample Location B-l @ 45' Sample Description brown silty sand PH 8.2 Minimum Resistivity (ohms-cm) 30,000 folubje Sulffltes; The soluble sulfate contents of selected samples were determined by standard geochcmical methods. The test results are presented in the table below: Sample Location B-l @ 45' Sample Description brown silty sand Sulfate Content (%) <0.005 ••••••^•^•••••••i Potential Degree of Sulfate Attack* negligible * Based on the 1994 edition of the Uniform Building Code, Table No. 19-A-3, prepared by the International Conference of Building Officials (ICBO, 1994). C c-i UWWfWMM»4fMCIf TO MC TOTPL P.12 Kleinfelder. Inc. Report of R-Value rKUJ*.Cl [NAME,:Cannon Road SAMrJL£: DAtfc 51-4100-02-006 TECH: coLU CD #5 Sta. 63+90 4/22/2000 M.B. CORRECTED R-VALUE REMARKS: OJive Brown Siity Clayey Sand R-VALUE: 8(K) 700 600 500 400 300 200 100 0 EXUDATION PRESSURE Kleinfelder, Inc. Report of R-Value PROJECT NAME:Cannon Road DATE: KLEINFELDER JOS NO.:51-4100-02-006 MJJ. LJJ CORRECTED R-VALUE REMARKS: Olive Brown Clayey Sand R-VALUE: 13 tOO 700 600 500 400 300 200 100 EXUDATION PRESSURE Kkinfelder, Inc. Report of R-Value PROJECT NAME:Cannon Road SAMPLE:Sta. 70+30 DATE: KLEINFELDER JOB NO.51-4100-02-006 TECH: oro COLLJCQ 4/22/2000 M.B. ORRECTED R-VALUE REMARKS: Tannish Brown Silty Clayey Sand R-VALUE: 13 600 500 400 300 200 100 0 EXUDATION PRESSUR£ Kleinfelder. Inc. Report of R-Value PROJECT NAME:Cannon Road SAMPLE: DATE: KLEINFELDER JOB NO.:TECH: CDoro #2 SO.71+SO 4/23/2000 M.B. :ORRECTED R-VALUE REMARKS: Light Brown Clayey Sand BOO 700 600 500 400 300 200 100 0 EXUDATION PRESSURE TOTftL P.07 Kleinfelder. Inc. Report of R-Value PROJECT NAME:Cannon Road SAMPLE: DATE: KLEINFELDER JOB NO.:51-4100-02-006 TECH: #4Sfc.7l+50 M.B. CORRECTED R-VALUE REMARKS: Olive Brown Silty Sand R-VALUE: 28 HOO 700 «00 500 400 300 200 100 EXUDATION PRESSURE Kleinfelder. Incr Report of R-Value PROJECT NAME:Cannon Road SAMPLE:#3 STA. 73+65 DATE:4/22/2000 KLEINFELDER JOB NO.:51-4100-02-006 TECH: LU OQ M.BT CORRECTED R-VALUE REMARKS: Tannish Brown Silty Sand R-VALUE: 33 SOO 700 £00 500 400 300 200 100 0 EXUDATION J'KJ-SSimn Kleinfelder. Inc. Report of R-Value PROJECT NAME:Cannon Road SAMPLE:#4 72+60 DATE: KLEINFELDER JOB NO.:51-4100-02-006 TECH: COLLJCO 4/23/2000 M.B. CORRECTED R-VALUE REMARKS: Olive Brown Silty Sand R-VALUE: 28 700 600 500 400 300 TOTAL P. 02