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Home My WebLink AboutCDP 14-05; TIERRA DEL ORO RESIDENCE; GEOTECHNICAL INVESTIGATION; DWG 487-2A; 2014-11-04C:f} /l / 5-(!;J:z/ I 3 Geotechnical Exploration, Inc. SOIL AND FOUNDATION ENGINEERING • GROUNDWATER • ENGINEERING GEOLOGY 04 November 2014 Tierra del Oro, LLC c/o Island Architects, Inc. 7626 Herschel Avenue La Jolla, CA 92037 Attn: Mr. Carson Nolan ;.Ju;~ 4.iJ21? RECEIVED JUN 19 2015 LAND DEVELOPMENT ENGINEERING Job No. 13-10316 Subject: Updated Addendum to Report of Geotechnical Investigation Ilerra del Qm Residential Project 5039 Tierra del Oro Carlsbad, California Dear Mr. Nolan: In accordance with the· request of Mr. Matt Peterson Geotechnica/ Exploration, Inc. has prepared this updated response to a City of Carlsbad Community and Economic Development Department/Planning Division comments dated September 3, 2014. We have previously prepared the following documents concerning the site and planned project: 1. "Report of Geotechnica/ Investigation and Coastal Bluff Edge Evaluation, Tierra de/ Oro Residential Project ... " dated November 12, 2013. This report was an evaluation of site geotechnical and geologic conditions for a planned residential remodel. 2. "Response to Coastal Bluff Edge Comments; Tierra def Oro Residential Project. .. " dated August 4, 2014. This letter responded to City of Carlsbad Development Services Department comments concerning our report. 3. "Addendum to report of Geotechnical Investigation; Tierra de/ Oro Residential Project. .. 0 dated September 11, 2014. This letter responded to City of Carlsbad Development Services Department comments on the stability of the coastal bluff and analysls of the planned swimming pool construction. 7420 TRADE STREET• SAN DIEGO, CA. 92121 • (858) 549-7222 • FAX: (858) 549-1604 • EMAIL: geotech@gei-sd.com Tierra del Oro Residential Remodel Carlsbad, California Job No. 13-10316 Page 2 City of Carlsbad staff has provided the following comments(September 3, 2014) to which we responded in our September 11, 2014, document: Please provide an addendum to the geotechnical report that addresses the effect of the project on the stability of the bluff ... If a pool is still proposed in the next submittal, please be sure to include in the report the construction of a new swimming pool near the top of the bluff and any other associated minor grading work that is being proposed. Since release of our September 11, 2014, addendum, we understand that the location of the planned swimming pool has been moved farther back from the coastal bluff edge. We have updated our bluff stability analysis to reflect this new location. We have also reviewed the following plans for the Tierra del Oro project: 1. "Tierra def Oro Residence" dated October 9, 2014, prepared by Island Architects, Inc., Sheets Al.Oa, Al.Ob and A2.1. 2. "Tierra def Oro Residence; 50 39 Tierra def Oro; Carlsbad, California, Site Plan" dated August 1, 2014, prepared by Island Architects. We also referred to the following earlier grading plan for the project for the elevation of existing features and the existing ground surface: 3. "Tierra de/ Oro Coastal Development Permit Preliminary Grading Plan'' dated July 29, 2014, prepared by Coffey Engineering, Inc. Sheet C-2. We have performed updated slope stability analyses through the site and coastal bluff using the referenced more recent plans. The analyses included the planned Tierra del Oro Residential Remodel Carlsbad, California Job No. 13-10316 Page 3 swimming pool at its new location. We note that the new proposed pool location will be located on site formational materials. As shown on the referenced plans, the pool will be constructed where there are formational soils. This area is a previously developed portion of the site that also currently includes a patio, fencing, walkways, and other improvements. We performed 16 separate new analyses representing the following conditions as shown on the referenced plans: analysis with no pool shell; analysis with no pool shell and with shake (seismic) force/loading; analysis with pool shell walls; analysis with pool shell walls and shake loading, analyses with and without retaining walls and pool shell walls; and analyses with and without retaining walls, pool shell walls and with shake loading. These are attached here as Appendix A, Slope Stability Analyses. All analyses yielded factors of safety of 1.5 or greater for non-seismic loading or 1.2 or greater for seismic loading. The coastal bluff is regarded as stable with respect to the effects of the planned project. Steep temporary unsupported slopes (e.g., retaining wall and pool shell excavations) yielded lower factors of safety. These are temporary construction related slopes and do not represent long-term risks at the site. Temporary slopes can be safely made at slope ratios of 1.0: 1.0 (horizontal to vertical) while vertical retaining walls or pool shells are built. CONCLUSIONS The planned residential project, including the planned swimming pool, will not destabilize the property or coastal bluff at the site. Tierra del Oro Residential Remodel Carlsbad, California LIMITATIONS Job No. 13-10316 Page 4 Our opinions have been based upon all available data obtained from our field investigations, reconnaissance and research, as well as our experience with the soils and native materials located in the Carlsbad area of the County of San Diego. The work performed and recommendations presented herein are the result of an investigation and analysis that meet the contemporary standard of care in our profession within the County of San Diego. This opportunity to be of service is sincerely appreciated. Should you have any questions concerning the following report, please do not hesitate to contact us. Reference to our Job No. 13-10316 will expedite a response to your inquiries. Respectfully submitted, ~~noN,INC. Jaime A. Cerros, P.E. R.C.E. 34422/G.E. 2007 Senior Geotechnical Engineer 0 0 .500 1.000 1.500 2 .000 2 .500 3.000 3.500 4.000 4 .500 5 .000 5 .500 6 .000+ 20 40 60 80 100 R.A.C. Material Name Color BEACH SAND (Qb) D FILL D RIP-RAP ~ FORMATION (Qop) D Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY RAC. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP $IMP. 120 140 Unit Weight (lbs/ft3) 110 120 135 120 TIERRA DEL ORO. LLC SLOPE STABllITY 1:275 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Strength Type Cohesion Phi Water Ru (lb/ft2) Surface Mohr-Coulomb 0 32 None 0 Mohr-Coulomb 50 32 None 0 Mohr-Coulomb 0 45 None 0 Mohr-Coulomb 50 42 None 0 180 200 220 JOB.N0.13-10316A01.sllm Safety Factor 0 .000 0.500 1.000 1.500 2.000 2 .500 3 .000 3 .500 4.000 4.500 5.000 5.500 6.000+ ~rr-,-... 0 20 I Material Name Color Unit Weight (lbs/ft3) BEACH SAND (Qb) D 110 FILL D 120 RIP-RAP ~ 135 FORMATION (Qop) D 120 Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP . Strength Type Mohr-Coulomb Mohr-Coulomb Mohr-coulomb Mohr-coulomb ~015 Cohesion Phi Water Ru (lb/ftZ) Surface 0 32 None 0 so 32 None 0 0 45 None 0 so 42 None 0 ....-;-r-.,....,.......,~, , , , I , .-;, ,"\' • , r-1~,·a,..-+iij 1" , .,.., 'f"1"+'+'"i"1 , 1 , , I , rl"''f'"Fi'T7-, r'" •• ~·"'i""iFr'a:""?l-,,.;'-?;-"'i"'i;;,;=;~,a;;:::;=;:aa;-;::,;:a:;,-:;;o,.:-;;:;;;:::;::;::::{I 40 60 100 120 140 1 180 200 220 TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 1:270 can..,y 10/13/2014, 9:19:37 AM JOB.N0.13-10316A01w_0.15gSHAKE.slim Print to PDF without this message by purchasing novaPDF (bttp://www.novapdf.comD Safety Factor 0 0 .000 0 .500 1.000 1.. 500 2 .000 2.500 3 .000 3.500 4 .000 4.500 s.ooo 5.500 6 .000+ 20 40 60 80 R.A.C. Material Name Color Unit Weight Strength Type (lbs/ft3) BEACH SANO (Qb) D 110 Mohr-Coulomb FILL D 120 Mohr-Coulomb RIP-RAP ~ 135 Mohr-Coulomb FORMATION (Qop) D 120 Mohr-Coulomb s~ ~-<-Tl ,1 A. 1 7 $ .... :s. ·~.., wi:-fh YI. C· f"c;~ j f,/,J)J Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 100 120 140 160 180 2 TIERRA DEL ORO. LLC SLOPE STABIUTY 1: 285 °""""1Y Cohesion (lb/ft2) 0 so 0 so 10/13/2014, 9:19:37 AM FlleName JOB.N0.13-10316A02.sflm Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Phi Water Ru Surface 32 None 0 32 None 0 45 None 0 42 None 0 220 2 Safety Factor 0 .000 0.500 1.000 l.500 2.000 2.500 3 .000 3.500 4.000 4.500 5,000 S.500 6.000+ It) Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. Material Name BEACH SAND (Qb) FILL RIP-RAP FORMATION (Qop) Color Unit Weight (lbs/ft3) D 110 D 120 ~ 135 D 120 = --------=---· 0 20 40 60 80 100 120 140 TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 1:280 ~015 Strength Type Cohesion Phi Water Ru (lb/ft2) Surface Mohr-Coulomb 0 32 None 0 Mohr-Coulomb so 32 None 0 Mohr-Coulomb 0 45 None 0 Mohr-Coulomb so 42 None 0 180 200 220 10/13/2014, 9:19:37 AM JOB.N0.13-10316A02w_0.1SgSHAKE.sllm Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Safety Factor 0 0. 000 0.500 1.000 1.500 2 .000 2 .500 3.000 3.500 4.000 4.500 5 .000 5.500 6 .000+ 20 60 80 R.A.C. Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 100 120 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Material Name Color Unit Weight Strength Type Cohesion Phi Water Ru (lbs/ft3) (lb/ft2) Surface BEACH SAND (Qb) D 110 Mohr-Coulomb 0 32 None 0 Fill D 120 Mohr-Coulomb so 32 None 0 RIP-RAP ~ 135 Mohr-Coulomb 0 45 None 0 FORMATION (Qop) D 120 Mohr-Coulomb 50 42 None 0 140 160 180 00 220 TIERRA DEL ORO. LLC SLOPE STABILITY 1:280 FIie IWame JOB.N0.13-10316A03.slim ---- Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3 .000 3.500 4.000 4.500 5.000 5.500 6.000+ 0 20 60 R.A.C. Material Name Color Unit Weight Strength Type (lbs/ft3) BEACH SAND (Qb) D 110 Mohr-Coulomb FILL D 120 Mohr-Coulomb RIP-RAP ~ 135 Mohr-Coulomb FORMATION (Qop) D 120 Mohr-Coulomb .f-.e<:s--.c ff/\tlf /~~C:.5 ~ !N .:+h rvol sl...t li Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP $IMP. 100 120 140 160 180 TIERRA DEL ORO. LLC SLOPE STABILITY 1 :280 CDn,i111r i,; 01' Cohesion Phi Water Ru (lb/ft2) Surface 0 32 None 0 50 32 None 0 0 45 None 0 50 42 None 0 200 220 10/13/2014, 9:19:37 AM JOB.N0.13-10316A03w_0.1SgSHAKE.slim Print to PDF without this message by purchasing novaPDF (bttp://www.novapdf.comD Safety Factor 0 0.000 0.500 1.000 1.500 2.000 2 .500 3.000 3.500 4 .000 4 .500 5.000 5.500 6.000+ 20 40 60 80 100 R.A.C. Material Name Color Unit Weight Strength Type {lbs/ft3) BEACH SAND (Qb) D 110 Mohr-Coulomb FILL D 120 Mohr-Coulomb RIP-RAP ~ 135 Mohr-Coulomb FORMATION (Qop) D 120 Mohr-Coulomb .::,:~'A-~ ;/,,.., ~ /;; s:...:.. > <i-w.:+t~ fc,e;,I SM t! Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY RAC. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 120 140 160 TIERRA DEL ORO. LLC SLOPE STABIUTY 1:280 180 Cohesion {lb/ft2) 0 so 0 so 200 10/13/2014, 9:19:37 AM JOB.N0.13-10316A04.sllm Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Phi Water Ru Surface 32 None 0 32 None 0 45 None 0 42 None 0 220 Safety Factor 0 0. ODO 0.500 1. 000 1 .500 2 .000 2.500 3 .000 3 .500 4.000 4.500 5.000 5 .500 6.000+ 20 40 60 80 120 R.A.C. 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Material Name Color Unit Weight Strength Type Cohesion Phi Water Ru (lbs/ft3) (lb/ft2) Surface BEACH SAND (Qb) D 110 Mohr-Coulomb 0 32 None 0 FILL D 120 Mohr-Coulomb 50 32 None 0 RIP-RAP Rx 135 Mohr-Coulomb 0 45 None 0 FORMATION (Qop) D 120 Mohr-Coulomb so 42 None 0 5'"~ .... s ,_ t.A-c An;, ,,~ s:..; • • .J r..u .:kh. y oo ! 6 h-e. l 1 • , •.... el sc..t:s """.;c t oc~ 140 160 180 2 220 TIERRA DEL ORO. LLC SLOPE STABIUTY 1:280 JOB.N0.13-10316A04w_0.1SgSHAKE.sllm Safety Factor 0 0.000 0 .500 1. 000 1. 500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 20 t.1~ 40 0100 lbslft2 238.00 lbslft2><::l 238.00 lbs/ft2 60 80 100 1'roj«:t Dl!lc1ptlM Material Name Color Unit Weight (lbs/ft3) BEACH SAND (Qb) D 110 FILL D 120 RIP-RAP ~ 135 FORMATION (Qop) D 120 Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 140 160 TIERRA DEL ORO. LLC SLOPE STABILITY Strength Type Cohesion (lb/ft2) Mohr-Coulomb 0 Mohr-Coulomb so Mohr-Coulomb 0 Mohr-Coulomb so 180 200 .... ~~ .. ~By R.A.C. 5c-, 1:280 ~ OD 6JX5 10/13/2014, 9:19:37 AM ,.._ JOB.N0.13-10316AOS.slim Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) Phi Water Ru Surface 32 None 0 32 None 0 45 None 0 42 None 0 220 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3 .000 3.500 4 .000 4 .500 5 .000 5.500 6.000+ o.~21b 238.00 lbs/ft2·~.~238.00 lbs/ft2 0 20 40 60 80 100 120 l'roj«t R.A.C. 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http:/lwww.novapdf.com/) Material Name Color Unit Weight (lbs/ft3) BEACH SAND (Qb) D 110 FILL D 120 RIP-RAP ~ 135 D 120 Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 140 160 TIERRA DEL ORO. LLC SLOPE SfABIL.TIY 1 :280 Cl>n""'1Y ~0.15 Strength Type Cohesion Phi water Ru (lb/ft2) Surface Mohr-Coulomb 0 32 None 0 Mohr-Coulomb 50 32 None 0 Mohr-Coulomb 0 45 None 0 Mohr-Coulomb 50 42 None 0 180 200 220 JOB.N0.13-10316AOSw_0.15gSHAKE.slim 0.500 1.000 1.500 2.000 2.500 3 .000 3.500 4.000 4.500 5.000 5.500 6.000+ 0 0 20 40 60 80 R.A.C. Material Name Color Unit Weight Strength Type Cohesion {lbs/ft3) (lb/ft2) BEACH SAND (Qb) D 110 Mohr-Coulomb 0 FILL D 120 Mohr-COulomb 50 RIP-RAP ~ 135 Mohr-Coulomb 0 D 120 Mohr-Coulomb so .7.;::i,i~c:.-..,, ,, ....... · 'r ~-.j ~iu;.+1. ~~i:.~-~ w,dl Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP . • I I I I I I' I Ii I. I I I I I I I •• ' I I I' 100 1 140 160 180 TIERRA DEL ORO. LLC SLOPE STABILITY 1:275 eon.,.n, ' 200 10/13/2014, 9:19:37 AM JOB.N0.13-10316A06.sllm Print to PDF without this message by purchasing novaPDF (bttp:/lwww.novapdf.com/) Phi Water Ru Surface 32 None 0 32 None 0 45 None 0 42 None 0 220 Safety Factor 0.000 Materf1I Name Color Unit Weight Strength Type Cohesion Phi Water Ru 0.500 (lbs/ft3) (lb/ft2) Surface ~015 l.000 BEACH SAND (Qb) D 110 Mohr-Coulomb 0 32 None 0 l.500 FILL D 120 Mohr-Coulomb 50 32 None 0 2.000 ~ RIP-RAP 135 Mohr-Coulomb 0 45 None 0 2.500 3.000 FORMATION (Qop) D 120 Mohr-Coulomb so 42 None 0 3.500 4.000 4.500 s.ooo 5.500 6.000+ 0 20 40 80 100 140 160 180 200 220 TIERRA DEL ORO. LLC SLOPE STABIUTY R.A.C. 1:280 10/13/2014, 9:19:37 AM JOB.N0.13-10316A06w_0.15gSHAKE.slim Print to PDF without this message by purchasing novaPDF (bttp://www.novapdf.com/) Safety Factor 0 .000 0 .500 1.000 1 .500 2.000 2.500 3 .000 3 .500 4 .000 4.500 5 .000 5.500 6.000+ Meterl•I Name BEACH SAND (Qb) FILL RIP-RAP FORMATION (Qop) Color Unit Weight (lbs/ft3) D 110 D 120 ~ 135 D 120 Strength Type Cohesion Phi Water Ru (lb/ft2) Surface Mohr-Coulomb 0 32 None 0 Mohr-Coulomb so 32 None 0 Mohr-<:oulomb 0 45 None 0 Mohr-Coulomb so 42 None 0 0.00 lbs/ft2'.---===-=-====i /. 1 .. ~ 880.00 lbs/ft2 238.00 lbslft2 . 238.00 lbslft2 C) -20 20 r -w .. -~..,,f ,.,_P_ro,1-·e_c_t-Su_m_m_a_ry __ ~ ~~7·, TIERRA DEL ORO. LLC /....J-.t Its(, SLOPE STABILITY 40 RAC. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 80 100 TIERRA DEL ORO. LLC SLOPE SfABIUTY R.A.C. 1:230 ~ 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) 120 140 160 JOB.N0.13-10316A07 .sum Safety Factor 0.000 0.500 1. 000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ Material Name BEACH SAND (Ob) FILL RIP-RAP FORMATION (Qop) Color Unit Weight (lbs/ft3) D 110 D 120 ~ 135 D 120 Strength Type Cohesion Phi Water Ru (lb/ft2) Surface Mohr-coulomb 0 32 None 0 Mohr-Coulomb so 32 None D Mohr-Coulomb 0 45 None 0 Mohr-Coulomb 50 42 None 0 0.00 lbs11t2r---==.....,=~-==t / qo.~~rtr aao.oo lbs/ft -2 0 20 40 R.A.C. 238.00 lbs/ft2~238.00 lbs/ft2 Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 60 100 TIERRA DEL ORO. LLC SLOPE STABILITY 1:230 ~ 10/13/2014, 9:19:37 AM Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/) 120 140 160 JOB.N0.13-10316A08.sllm Safety Factor 0 .000 0 .500 1.000 1 .500 2.000 \ I 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ -20 0 t.1~ ~~~ .. 6.005 8 .. u.e h. ~k 4 r·.e,._ w ,:4-1... S< t:s~ lo~. ----· 2 40 flro}«t ~ R.A..C .. Material Name Color Unit Weight Strength Type (lbs/ft3) BEACH SAND (Qb) D 110 Mohr-Coulomb Fill D 120 Mohr-Coulomb RIP-RAP ~ 135 Mohr-Coulomb FORMATION (Qop) D 120 Mohr-Coulomb Cohesion Phi Water Ru (lb/ft2) Surface 0 32 None 0 50 32 None 0 0 45 None 0 50 42 None 0 0.00 lbslft2------=-=====i I ----:sao.oo lbs/ft2' ....... --~:,,J Project Summary TIERRA DEL ORO. LLC SLOPE STABILITY R.A.C. 10/13/2014, 9:19:37 AM CROSS-SECTION A-A' BISHOP SIMP. 60 80 100 TIERRA DEL ORO. LLC SLOPE STABIUTY 1:230 120 140 160 ~ 10/13/2014, 9:19:37 AM JOB.N0.13-10316A08w_0.15gSHAKE.sllm Print to PDF without this message by purchasing novaPDF (http://www.novapdf.com/)