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Home My WebLink AboutCT 16-03; BEACH VILLAGE LIFE 1 MIXED USE; GEOTECHNICAL RESPONSE; 2020-02-14RD COPY RECO - ~~v -k 11 --?-* Initial Date GEOTECHNICAL RESPONSE TO CITY OF CARLSBAD LAND DEVELOPMENT ENGINEERING REDLINE REVIEW COMMENTS AND REVIEW OF PRECISE GRADING AND SHORING PLANS/STRUCTURAL CALCULATIONS INSTRUCTION CHANGE SET), BEACH VILLAGE LIFE MIXED-USE HOTEL SPA, AND CONDOMINIUMS, 300 CHRISTIANSEN WAY == Geotechnical Geologic• Environmental GEOTECHNICAL RESPONSE TO CITY OF CARLSBAD LAND DEVELOPMENT ENGINEERING REDLINE REVIEW COMMENTS AND REVIEW OF PRECISE GRADING AND SHORING PLANS/STRUCTURAL CALCULATIONS (CONSTRUCTION CHANGE SET), BEACH VILLAGE LIFE MIXED-USE HOTEL SPA, AND CONDOMINIUMS, 300 CHRISTIANSEN WAY 381 CHRISTIANSEN WAY CARLSBAD, CALIFORNIA 92008 W.O. 6942-Al-SC FEBRUARY 14,2020 Geotechnical. Geologic. Coastal • Environmental 5741 Palmer Way • Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 • www.geosoilsinc.com February 14, 2020 W.O. 6942-Al-SC Beach Village Life 1, LLC do Karnak Planning and Design 381 Christiansen Way Carlsbad, California 92008 Attention: Mr. Robert Richardson Subject: Geotechnical Response to City of Carlsbad Land Development Engineering Redline Review Comments and Review of Precise Grading, and Shoring Plans/Structural Calculations (Construction Change Set), Beach Village Life Mixed-Use Hotel, Spa, and Condominiums, 300 Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, City of Carlsbad Project No.: CT 16-03 Dear Mr. Richardson: In accordance with Mr. Bill Davidson's request and authorization, GeoSoils, Inc. (GSI) is providing this response to the City of Carlsbad Land Development Engineering's "redline" geotechnical report review comments that require our attention (City of Carlsbad [City], 2019a and 2019b [see the Appendix]). In addition, a summary of our review of the construction change set of the precise grading and shoring plans (Spear and Associates, Inc. [S&A], 2020 and Sun Structural Engineering, Inc. [SSE], 2020b), and shoring structural calculations (SSE, 2020a) is included herewith. The services GSI performed for this study included a review of the documents referenced in the Appendix and the preparation of this response. Unless specifically superseded herein, the conclusions and recommendations contained in the referenced GSI reports (see the Appendix) are still considered valid and applicable, and should be appropriately implemented during project design and construction. It is our understanding that the City's redline review comment pertaining to GSI (2019a) has been resolved; and therefore, does not require a response by GSI. RESPONSE TO CITY REVIEW COMMENTS General The City review comments are summarized below in italics, followed by GSI's response. Response to City (2019a) City Redline Comments Provided on the Cover Page and Page 27 of GSI (2018c) The City is requesting clarification regarding the extent of geotechnical inspections (i.e., continuous or periodic inspections) for each construction task listed under the "Updated Summary of Recommendations Regarding Geotechnical Observation and Testing" heading in GSI's geotechnical update evaluation report for the project (GSI, 2018c) as well as the GSI personnel positions responsible for these geotechnical inspections. GSI Response Our response is summarized in the following tabulated inspection matrix. In general, the extent of geotechnical inspections (continuous or periodic) should conform to the requirements in Chapter 17 of the California Building Code ([CBC], California Building Standards Commission, 2016). CONSTRUCTION TASK CONTINUOUS I PERIODIC GSi PERSONNEL RESPONSIBLE INSPECTION INSPECTION FOR INSPECTION Drilling for Shoring Soldier Piles x -- Field Engineer or Geologist During Planned Excavations - x Field Engineer or Geologist During Grading (Overexcavation) - x Field Technician* During Grading X - Field Technician* (Compacted Fill Placement) Subdrain Installation - x Field Technician* Drilling for Cast-In-Drilled Hole x .- Field Engineer or Geologist (CIDH) Pile Foundations Foundation/Grade Beam X Field Technician* Excavations 7 Subgrade Preparation and Compaction X Field Technician* (Slab-On-Grade, Pavements, and - Hardscape) Aggregate Base Placement and Compaction -- X Field Technician* (Pavements) Asphaltic Concrete Placement and X Field Technician* Compacton - Underground Utility Trench Backfill - x Field Technician* * - A Field Engineer/Geologist may also perform these inspections. Beach Village Life 1, LLC W.O. 6942-Al-SC 300 Christiansen Way, Carlsbad . February 14, 2020 File:e:\wpl2\6900\6942a1.grt2 GeoSoils, Inc. Page 2 Response to City (2019b) City Redline Comment Provided on Page 20 of GSI (2018d) The City is requiring the numerical values for the coefficient of active earth pressure ('ce) and the unit weight of soil (y) used in the empirical formula we provided for calculating the lateral earth pressure acting upon the shoring lagging. GSI Response The requested numerical values are as follows: K= 35H (35 pounds per square foot [psfj multiplied by the height of the retained soil [35 psflft]) y = 105 to 115 pounds per cubic foot (pcf) These values may be used in the lagging design for the currently planned temporary shoring. City Redline Comment Provided on Page 21 of GSI (2018d) The City is requesting clarification of equivalent fluid pressures recommended for temporary and permanent shoring in the first paragraph on page 21 of GS! (2018d). GSI Response The first paragraph on page 21 of GSI (2018d) contained a typographical error. Thus, GSI has corrected this paragraph below: As recommended in Figure 3 of GSI (2015), an equivalent fluid pressure (EFP) of 35H (35 pounds per square foot [psf] multiplied by the height of the retained soils [H]) should be used in the design of the temporary shoring. Whereas, Figure 4 of GSI (2015) recommends an EFP of 45H (45 psf multiplied by the height of the retained soils [H]) for the design of permanent shoring with bracing (i.e, all floors near the top, middle and bottom of the shore excavation). The old paralic deposits and the underlying, denser Santiago Formation are considered competent earth materials. In both the temporary and permanent cases, these earth materials may be considered drained, if drainage is included in the shoring details. REVIEW OF S&A (2020) AND SSE (2020a AND 2020b) Based on our review, the construction change set of the precise grading and shoring plans/structural calculations (S&A, 2020; SSE, 2020a; and SSE, 2020b) are in general Beach Village Life 1, LLC W.O. 6942A1-SC 300 Christiansen Way, Carlsbad February 14, 2020 File:e:\wpl2\6900\6942a1.9rt2 GeOSoils, Inc. Page 3 accordance with the recommendations provided in the project geotechnical reports prepared by GSI (see the Appendix). GSI should be provided with the opportunity to review any significant revisions to SM (2020) and SSE (2020a and 2020b) that involve the project subsurface conditions and geotechnical recommendations, should any plan/structural calculation amendments occur following the issuance of this document. Plates 1, 2, and 3 provide the inferred geologic conditions along the west, north, and south shoring walls, respectively. LIMITATIONS The conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that maybe in place. In addition, this report maybe subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. Beach Village Life 1, LLC W.O. 6942-Al-SC 300 Christiansen Way, Carlsbad February 14, 2020 File:e:\wpl2\6900\6942a1.grt2 GeoSoils, Inc. Page 4 If you have any questions or comments regarding this letter, please do not hesitate to contact the undersigned. Respectfully GeoSoils, Inc. 1 a_I No. 1340 1 I Certified I MJ! EngIneerfng J (P 010910 ngineering Geologist,40 4d'ffo`ihmer-- Project Geologist RBB/JPF/ATG/mn VSOESSm Ir háei1i OF C Geotechnical Engineer, GE2S20' Attachment: Appendix - References Plate 1 - Inferred Geologic Conditions at West Shoring Wall Plate 2 - Inferred Geologic Conditions at North Shoring Wall Plate 3 - Inferred Geologic Conditions at South Shoring Wall Distribution: (1) Addressee (PDF via email) (1) Sun Structural Engineering, Inc., Attn: Mr. Changhua Sun (PDF via email) (3) Arch Studio 12, Inc., Attn: Mr. Richard Johnson (US mail and PDF via email) (1) Spear and Associates, Inc., Attn: Mr. Josh Ziegler (PDF via email) Beach Village Life 1, LLC W.O. 6942-Al-SC 300 Christiansen Way, Carlsbad February 14, 2020 File:e:\wp12\6900\6942a1 .gr12 GeOSoils, Inc. Page 5 APPFNflIY REFERENCES California Building Standards Commission, 2016, California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, based on the 2015 International Building Code, 2016 California Historical Building code, Title 24, Part 8, 2016 California Existing Building Code, Title 24, Part 10, and the 2015 International Existing Building Code. City of Carlsbad Land Development Engineering, 2019a, Redline review comments, GeoSoils, Inc. report entitled 'Geotechnical Update Evaluation, Planned Mixed-Use Hotel, Spa, and Condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00," dated August 5. 2019b, Redline review comments, GeoSoils, Inc. report entitled "Revised Cast-In- Drilled-Hole (CIDH) Pile Recommendations, Planned Mixed-Use Hotel, Spa, and Condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00," dated August 5. GeoSoils, Inc., 2019a, Geotechnical review of revised shoring plans and sheet 4 of the precise grading plans, planned mixed-use hotel, spa, and condominiums, 300 Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, City of Carlsbad Project No.: CT 16-03, W.O. 6942-Al - SC, dated June 26. 2019b, Geotechnical review of structural plans and calculations, planned mixed-use hotel, spa, and condominiums, 300 Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, City of Carlsbad Project No.: CT 16-03, W.O. 6942-Al-SC, dated June 13. 2018a, Geotechnical review of grading and shoring plans, planned mixed-use hotel, spa, and condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, City of Carlsbad project no.: CT 16- 03, W.O. 6942-Al -SC, dated October 11. 2018b, Geotechnical response to City of Carlsbad third-party plan check and Engineering Department review comments, planned mixed-use hotel, spa, and condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, City of Carlsbad Project No.: CT 16- 03, W.O. 6942-Al -SC, dated May 30. 2018c, Geotechnical update evaluation, planned mixed-use hotel, spa, and condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, W.O. 6942-Al-SC, dated February 15. GeoSoils, Inc. 2018d, Revised cast-in-drilled-hole (CIDH) pile recommendations, planned mixed-use hotel, spa, and condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, W.O. 6942-Al-SC, dated February 5. 2017, Supplemental geotechnical recommendations, proposed mixed-use hotel, spa, and condominiums, Christiansen Way, Carlsbad, San Diego County, California, Assessor's Parcel Number (APN) 203-173-02-00, dated October 23. 2015, Preliminary geotechnical evaluation, APN 203-173-02-00, Carlsbad, San Diego County, California, W.O. 6942-A-SC, dated September 11. Spear and Associates, Inc., 2020, Precise grading plan for: Beach Village Life, Christiansen Way, plan & sections, sheets 1 through 4 of 13, various scales, City of Carlsbad project no.: 16-03, drawing no.: 508-9A, revision (delta 1) dated February 7. Sun Structural Engineering, Inc., 2020a, Structural calculations for: Beach Village Life 1, mixed use hotel, spa & condominiums shoring design revision, 2 pages, dated February 10. 2020b, Shoring plans for: Beach Village Life 1 mixed use hotel, spa & condominiums, Sheets S-i, S-2, S-3 SD1, SD2, and SD-3, various scales, plot dated February 4. Beach Village Life 1, LLC Appendix File:e:\wpl2\6900\6942a1.grt2 GeoSoils, Inc. Page 2 wI PIL PROPOSED MIXED—USE BUILDING IP/L 18-2 PROJECTED (GSI, 2018c) 8-2 PROJECTED 8-3 PROJECTED B-i PROJECTED j9-4 PROJECTED (GSI, 2015) (GS1, 2015) (I (UN, 20(5) KIN (GSI, 2018c) tI Property line - Qcol— )Main Level Main Level A 55' 711 Sub Level I 48'-lO" DI mo Sub Level 2 39' - OH -In _J IU Ltj 0 - —10 - - —10 —20 - --20 —30 - --30 r.1Ut:i1:I.JIwic1 !LYU MVAVl I.J:Lc1iiil*1i'I.J ALL LOCATIONS ARE APPROXIMATE This document or efile is not a part of the Construction Documents and should not be relied upon as being an accurate depiction of design. GRAPHIC SCALE 10 0 5 10 20 40 II 1" = 10' BASE PROFILE BY.8 ARCH STUDIO 12, INC 70 P/Li PROPOSED MIXED-USE BUILDING 'P/L 70 B-3 PROJECTED 18-1 PROJECTED 8-2 PROJECTED (GSI, 2015) (GsI, 2018c) (GSI, 2015) 60 Property line ( 1 Plate steel lagging for this type of h itching - - Shotcrete lagging - 12' max. grade g_ -Steel column to terminate at Steel colum to terminate at Main Steel column to termin te at Main Level Deck B 1 7ain Level B 60 g depth underside of entry stairs - - - - - - - - - - Qcol r J EXISTIG GRADE ,,i- Grade cut back slope - - Existhig grade line - ______ - 183 PROJECTED - B1RoJEcTED - ______ - Property line an QOP - QC01 — J-46' 4111111111040M (WEA wo Qmmmw- Grade cutback a 37'- 8" j;E :: _ L!iPL H _____________ __ 50 TD=6 Y4 Bottom of grade beam line 34'- E 3617 39, —0~ Q ID 177 0 34.67 j i 77 77777 30 30 Qop Top of Dry, LLJ LLj Friable Sand Layer= ThH HThTh 'QOP 18.08 _, ___ ___ ___ _____ H 20 20 1 TD=36 TD=31 Y2' 77 LLJ 10 L Tsa Tsa Tsa H 10 1.92-1 08 H L 308 HHHHHHH 7D=56'I -10 !I.]:4tIJa'I.]:4R1c1 !kYU Vt .............. I.i;LtMii*ifI'J ALL LOCATIONS ARE APPROXIMATE This document or efile is not a part of the Construction Documents and should not be relied upon as being an accurate depiction of design. BASE PROFILE BY., ARCH STUDIO 12, INCR GRAPHIC SCALE- 10 0 5 to 20 40 I I 7" = 10' 70 1 PAL PROPOSED MIXED-USE BUILDING P/L - 70 Iwo 50- Wo Main Level A U 55'-7" ;Ub Level 1 48 % ubLevel 2 39' - 0" Wei (N 30- LLJ 20- 9 Qco! - QUATERNARY COLLUV!UM/DISTURBED NATURAL GROUND Qop - QUATERNARY OLD PARAUC DEPOSITS Tsa - TERTIARY SAN 71AGO FORMATION - APPROXIMATE LOCATION OF GEOLOGIC CONTACT, QUERIED WHERE UNCERTAIN V - ES17MA TED PERCHED GROUND WA TER SURFACE - ESTIMATED REGIONAL GROUND WA TER SURFACE - PLANNED LOCATION OF 36"0 SOLDIER PILE - EXISTING EXTERNAL SURFACE GRADE - APPROXIMATE AREA OF RECOMMENDED OVEREXCA VA TION AND REPLACEMENT FILL - In _J IL) LU 1-1/4" STL PLATE LAGGING 0- -0 --10 -20- --20 -30- --30 !a VIIii.k4RIci!A?YU ALL LOCATIONS ARE APPROXIMATE This document or efile is not a part of the Construction Documents and should not be relied upon as being an accurate depiction of design. GRAPHIC SCALE 10 0 5 10 20 40 1" - 10' !AY All Nill 1111~` 1t