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HomeMy WebLinkAbout20210419_Geotechnical Investigation_12-22-2020consultants UPDATED GEOTECHNICAL INVESTIGATION FOR PROPOSED RESIDENTIAL REMODEL LOCATED AT 1740 E. OCEANFRONT NEWPORT BEACH , CALIFORNIA Presented to: JIM & CATHY CEFALIA P.O. Box 4212 Newport Beach, CA 92661 clo: ROST Architects Attn: Sarah Berting 16530 Bake Parkway Irvine, CA 92618 Prepared by: EGA CONSULTANTS, Inc. 375-C Monte Vista Avenue Costa Mesa, California 92627 ph (949) 642-9309 fax (949) 642-1290 December 22, 2020 Project No. JC282.1 engineering geotechnical applications 37 5 -C Monte Vista Avenue• Costa Mesa, CA 92627 • (949) 642-9309 • FAX (949) 642-1 290 consultants engineering geotechnical applications December 22, 2020 Project No. JC282.1 Site: Proposed Remodel -17 4 0 E. Oceanfront Newport Beach, C alifornia -Significant Grading is Not Planned Executive Summary Based on our geotechnical study of the site, our review of available reports and literature and our experience, it is our opinion that the proposed residential improvements are feasible from a geotechnical standpoint. There appear to be no significant geotechnical constraints on-site that cannot be mitigated by proper planning, design, and utilization of sound construction practices. The engineering properties of the soil and native materials, and surface drainage offer favorable conditions for site development. The following key elements are conclusions confirmed from this investigation: A review of available geologic records indicates that no active faults cross the subject property. The site is located in the seismically active Southern California area, and within 2 kilometers of the Type B Newport-Inglewood Fault. As such, the proposed development shall be designed in accordance with seismic considerations specified in the 2019 California Building Code (CBC) and the City requirements. The limits of the proposed remodel are located entirely within the existing building footprint. SUMMARY OF RECOMMENDATIONS: Design Item Foundations: Recommendations Footing Bearing Pressures: Passive Lateral Resistence Perimeter/Interior Footing Widths: 1,750 psf -building, continuous 2,250 psf -building, isolated column 250 psf per foot Perimeter/Interior Footing Depths: Coefficient of Friction: min. 15 inches with two No. 5 bars top and bottom min. 30 inches below lowest adjacent grade Soil Expansion: 0.30 Very Low (El = 0) Negligible, SO Soil Sulfate Content Soil Maximum Density: 111.0 pct@ 13.5% Opt. Moisture Building Slab -if applicable: * Concrete slabs cast against properly compacted fill materials shall be a minimum of 5 inches thick (actual) and reinforced with No. 4 rebar at 18 inches on center in both directions. * Dowel all footings to slabs with No. 4 bars at 24 inches on center. Seismic Values (Equivalent Lateral Force Method): Site Class Definition (Table 1613.5.2) Mapped Spectral Response Acceleration at 0.2s Period, S5 Mapped Spectral Response Acceleration at 1 s Period, S, Short Period Site Coefficient at 0.2 Period, F. Long Period Site Coefficient at 1 s Period, F v Adjusted Spectral Response Acceleration at 0.2s Period, SMs Adjusted Spectral Response Acceleration at 1s Period, SM, Design Spectral Response Acceleration at 0.2s Period, Sos Design Spectral Response Acceleration at 1 s Period, s01 D 1.377 g 0.488 g 1.2 1.8 1.653 g 0.878 g 1.102 g 0.586 g PGAm = 0.724 g 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • FAX (949) 642-1290 consultants JIM & CATHY CEFALIA P.O. Box 4212 Newport Beach, CA 92661 c/o: Subject: Dear Team, ROST Architects, Attn: Sarah Berting UPDATED GEOTECHNICAL INVESTIGATION FOR PROPOSED RESIDENTIAL REMODEL LOCATED AT 17 40 EAST OCEANFRONT NEWPORT BEACH, CALIFORNIA engineering geotechnical applications December 22, 2020 Project No. JC282.1 In accordance with your request we have completed our Geotechnical Investigation of the above referenced site located in the City of Newport Beach, California. This investigation was performed to determine the site soil conditions and to provide geotechnical parameters for the proposed site additions and associated improvements. This opportunity to be of service is appreciated. If you have any questions, please call. Very truly yours, EGA Consultants, Inc. DAVID A. WORTHINGTON, CEG 2124 Principal Engineering Geologist/P EO JOHN F. EGGERS Staff Geologist Copies (3) Addressee PAUL DURAND Sr. Project Engin 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • FAX (949) 642-1290 UPDATED GEOTECHNICAL INVESTIGATION FOR PROPOSED RESIDENTIAL REMODEL LOCATED AT 1740E.OCEANFRONT NEWPORT BEACH , CALIFORNIA Associated References: December 22, 2020 Project No. JC282.1 1. "Geotechnical Report, Proposed Two-Story, Single Family Residences, 1740 East Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated September 30, 1994. 2 "Geotechnical Report of Rough Grading, Proposed Single Family Residences, 1740 and 1744 E. Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated December 8, 1994. • 3. "Final Soils Report, Interior and Exterior Utility Trench and Retaining Wall Backfill, 1740 East Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated September 11, 1995. CHANGE OF ENGINEER OF RECORD This statement is prepared to inform you that EGA Consultants, Inc. Is replacing Petra Geotechnical Inc. As the geotechnical Engineer of Record for the above-referenced project. EGA Consultants, Inc., has reviewed and approved the above-referenced soils report for the proposed site additions. The following update report (dated December 22, 2020) provides supplementary/confirmatory data and updated recommendations in accordance with the 2019 CBC (including seismic parameters). Significant grading is not being proposed. The proposed additions will not significantly expand the current building footprint built circa 1995. INTRODUCTION ln response to your request and in accordance with the City of Newport Beach Building Department requirements, we have completed a geotechnical investigation at the subject site located at 1740 E. Oceanfront, in the City of Newport Beach, California (see Site Location Map, Figure 1). The purpose of our investigation was to evaluate the existing geotechnical conditions at the subject site and provide recommendations and geotechnical parameters for site re- development, earthwork, and foundation design for the proposed re-construction. We were also requested to evaluate the potential for on-site geotechnical hazards. This report presents the results of our findings , as well as our conclusions and recommendations. SCOPE OF STUDY The scope of our investigation included the following tasks: • Review of readily available published and unpublished reports; • Geologic reconnaissance and mapping; 2 • Excavation and sampling of one (1) exploratory boring to a total depth of 12 feet below existing grade (b.g.); • Laboratory testing of representative samples obtained from the exploratory borings; • Engineering and geologic analysis including seismicity coefficients in accordance with the 2019 CBC; • Preparation of this report presenting our findings, conclusions, and recommendations. GENERAL SITE CONDITIONS The subject property is an 80 feet long by 50 feet wide rectangular-shaped lot located at 1740 E. Oceanfront within the City of Newport Beach, County of Orange, California (see Site Location Map, Figure 1 ). For the purpose of clarity in this report, the lot is bound by E. Oceanfront to the north, by similar residential dwellings to the east and west, and by a sandy public beach to the south. The lot is located near the eastern end of the Balboa Peninsular; approximately 400 feet northeast of the Pacific Ocean (see Figure 1). Currently, the lot is occupied by a two-story, residential structure situated on a graded level pad. The residence, built circa 1995, is supported on continuous perimeter footings with slab-on-grade floors. An attached two-car garage is located in the southeast corner of the residence and is accessed by the rear alley. The site is legally described as Parcel 1 of Block C, of Tract No. 518 (APN 048-212-19). The existing site layout is shown in the Plot Plan, Figure 2, herein. PROPOSED RESIDENTIAL REMODEL Based on our review of the preliminary architectural plans by ROST Architects, the proposed residential remodel consists of an internal rearrangement of the residence. The proposed construction shall not provide new building footprint square footages (the limits of the proposed remodel are located entirely within the existing building footprint). We assume that the proposed building will consist of wood-frame and masonry block construction or building materials of similar type and load. The building foundations will consist of a combination of isolated and continuous spread footings. Loads on the footings are unknown, but are expected to be less than 2,250 and 1,750 pounds per square foot on the isolated and continuous footings, respectively. If actual loads exceed these assumed values, we should be contacted to evaluate whether revisions of this report are necessary. Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Beach, CA -Soils Report Project No. JC282. I December 22, 2020 3 Based on NAVD88, the site elevation is approximately 13 ft. above MSL. Based on the preliminary plans, the proposed finish floor elevation shall be 9+ ft. above mean sea level (MSL) to conform with City and United States FEMA flood elevation requirements. Note: The precise determination, measuring, and documenting of the site elevations, hub locations, property boundaries, etc., is the responsibility of the project licensed land surveyor. It is our understanding that the grade of the site is not expected to vary significantly. Significant grading or retaining walls are not proposed. SUBSURFACE EXPLORATION Our subsurface exploration consisted of the excavation of one (1) exploratory boring (B-1) to a total depth of 12 feet below grade (b.g.). Prior to drilling, the underground detection and markup service (Underground Service Alert of Southern California) was ordered and completed. Representative bulk and relatively undisturbed soil samples were obtained for laboratory testing. Geologic logs of the soil borings are included in Appendix A. The boring was continuously logged by a registered geologist from our firm who obtained soil samples for geotechnical laboratory analysis. The approximate locations of the boring is shown on Figure 2, Plot Plan. Geotechnical soil samples were obtained using a modified California sampler filled with 2 % inch diameter, 1-inch tall brass rings. Bulk samples were obtained by collecting representative bore hole cuttings. Locations of geotechnical samples and other data are presented on the boring logs in Appendix A. The soils were visually classified according to the Unified Soil Classification System. Classifications are shown on the boring logs included in Appendix A. LABORATORY TESTING Laboratory testing was performed on representative soil samples obtained during our subsurface exploration. The following tests were performed : * * Soil Classification (ASTM: D 2487) Dry Density and Moisture Content (ASTM: D 2216) Proposed Additions -Ccfalia Remodel 1740 E Oceanfront, Newport Beach. CA -Soils Report Project No. JC282. I December 22. 2020 4 * * * Maximum Dry Density and Optimum Moisture Content (ASTM: 01557) Direct Shear (ASTM 03080) Sulfate Content (Hach Procedure, ACI 318-08, Table 4.2.1) All laboratory testing was performed by our sub-contractor, G3/SoilsWorks, Inc., of Costa Mesa, California. Geotechnical test results are shown in Appendix B of this report. SOIL AND GEOLOGIC CONDITIONS The site soil and geologic conditions are as follows: Seepage and Groundwater Seepage or surface water ponding was not noted on the subject site at the time of our study. According to the Orange County Water District (OCWD), there are no water wells located within the general vicinity of the subject property. The Pacific Ocean shoreline is approximately 400 feet southwest of the site. Channel waters of the Newport Bay are located approximately 1,200 feet to the north (see Figure 1, Site Location Map herein). Depths to groundwater are influenced by tidal fluctuations. A tidal chart during the month of November is presented as Figure 4, herein. Geologic Setting According to a United States Geological Survey (USGS) Map of the Newport Beach Quadrangle the site is approximately 13 feet above Mean Sea Level (MSL). Regionally, the site is located within the western boundary of the Coastal Plain of Orange County. The Coastal Plain lies within the southwest portion of the Los Angeles Basin and consists of semi-consolidated marine and non-marine deposits ranging in age from Miocene to recent. The western boundary of the Coastal Plain, in which the site is located, is referred to as the Tustin Plain. It is bound by the Santa Ana Mountains to the northeast and the San Joaquin Hills to the southeast. Based on available geologic maps the site is underlain by a thin mantle of eolian (Qe)/hydraulic sands and/or engineered fill. The shallow soil layer is underlain by Quaternary-age old paralic deposits (Qop) which are described as medium dense to very dense, oxidized, fine to medium grained, moderately to well-cemented sand Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Bead,, CA -Soils Report Project No JC282. I December 22, 2020 5 and silty sand (see reference No. 2). The old paralic deposits are underlain by massive bedrock of the Monterey Formation (Tm). Roadside exposures of massive bedrock of the Monterey Formation (Tm) are visible on the inland side of side of Bayside Avenue and Pacific Coast Highway less than 1 kilometer north and northwest of the site (Dover Shores bluffs). A Geologic Map is presented as Figure 3, herein (reference: Morton, D.M., and Miller, F.K., 2006). ' Faulting A review of available geologic records indicates that no active faults cross the subject property (reference No. 2). Seismicity The seismic hazards most likely to impact the subject site is ground shaking following a large earthquake on the Newport-Inglewood (offshore), San Joaquin Blind Thrust, Palos Verdes (offshore), Whittier-Elsinore, or Cucamonga. The site is underlain by fill and silty sands which become more cemented with depth. For design purposes, two-thirds of the maximum anticipated bedrock acceleration may be assumed for the repeatable ground acceleration. The effects of seismic shaking can be mitigated by adhering to the 2019 California Building Code or the standards of care established by the Structural Engineers Association of California. With respect to this hazard, the site is comparable to others in this general area in similar geologic settings. The grading specifications and guidelines outlined in this preliminary report are in part, intended to mitigate seismic shaking. These guidelines conform to the industry standard of care and from a geotechnical standpoint, no additional measures are warranted. Based on our review of the "Seismic Zone Map," published by the California Department of Mines and Geology in conjunction with Special Publication 117, there are no earthquake landslide zones on or adjacent to the site. The proposed development shall be designed in accordance with seismic considerations contained in the 2019 CBC and the City of Newport Beach requirements. Based on Chapter 16 of the 2019 CBC and on Maps of Known Active Near-Source Zones in California and Adjacent Portions of Nevada (ASCE 7-10 Standard), the following parameters may be considered: Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Beach, CA -Soils Rcpo,rt Project No. JC282. I December 22, 2020 6 2019 CBC Seismic Design Parameters (Equivalent Lateral Force Method) S DRESS fr N h C ITEAD -: 1740 E. Ocean ont, ewport Beac , A Site Latitude (Decimal Degrees) 33.5965103 Site Longitude (Decimal Degrees) -117.8875953 Site Class Definition D Mapped Spectral Response Acceleration at 0.2s Period, S5 1.377 g Mapped Spectral Response Acceleration at Is Period, S 1 0.488 g Short Period Site Coefficient at 0.2 Period, Fa 1.2 Long Period Site Coefficient at ls Period, Fv 1.8 Adjusted Spectral Response Acceleration at 0.2s Period, SMs 1.653 g Adjusted Spectral Response Acceleration at Is Period, SM1 0.878 g Design Spectral Response Acceleration at 0.2s Period, S05 1.102 g Design Spectral Response Acceleration at 1 s Period S0 1 0.586 g In accordance with the USGS Design Maps, and assuming Site Class "D", the mean peak ground acceleration (PGAm) per USGS is 0.724 g. The stated PGAm is based on a 2% probability of exceedance in a 50 year span. A copy of the site USGS Design Map Summary report provided in Appendix C, herein. FINDINGS Subsurface Soils As encountered in our test borings, the site is underlain by fill and native materials as follows: Fill (Af) Fill soils were encountered in the test boring (B-1) to a depth of approximately 3 feet b.g. The fill soils consist generally of light gray brown, dry to damp, loose to medium dense, poorly sorted sand with shell fragments. The expansion potential of the fill soils was judged to be very low when exposed to an increase in moisture content (Expansion Index of 0). Hydraulic-Native Sands (Qe). Paralic Deposits (Qop) and Bedrock (Tm) Underlying the fill materials are hydraulic and native sands as encountered Proposed Additions -Ccfalia Remodel 1740 E Oceanfront, N,;wport Beach. CA -Soils Report Project No. JC282. I December 22, 2020 7 in each of the test borings. The native sands consist generally of tan brown, damp, medium dense to dense, non-cemented, fine-to medium-grained sand with shell fragments. The native sands are underlain by eolian (Qe) and old paralic (Qop) deposits, which are underlain by Monterey Formation (Tm) bedrock consisting of medium dense to very dense, oxidized, fine to medium grained, moderately· to well-cemented sand and siltstone. CONCLUSIONS Based on our geotechnical study of the site, our review of available reports and literature and our experience, it is our opinion that the proposed improvements at the site are feasible from a geotechnical standpoint. There appear to be no significant geotechnical constraints on-site that cannot be mitigated by proper planning, design, and utilization of sound construction practices. The engineering properties of the soil and native materials, and the surface drainage offer favorable conditions for site re-development. RECOMMENDATIONS The following sections discuss the principle geotechnical concerns which should be considered for the proposed additions. Significant grading, nor expansion of the existing building footprint, is not proposed. Site Preparation Prior to earthwork or construction operations, the areas of the proposed site additions should be cleared of surface structures and subsurface obstructions and stripped of any vegetation in the areas proposed for development. Removed vegetation and debris should then be disposed of off-site. Building Additions/Remodel To eliminate the over-excavation requirements, we recommend the following for the proposed building addition/remodel construction: * * All proposed footings may be deepened as follows: a minimum 30 inches deep, below lowest adjacent grade. All footing trenches shall be inspected by representatives of EGA Consultants. If applicable, we recommend a minimum 10 inches of soil beneath the floor slabs be removed and re-compacted to a minimum 90% relative compaction. This method will eliminate' removal and re-compaction of the upper 2½ feet. All Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Beach, CA -Soils Report Project No. JC282. I December 22, 2020 8 footing bottoms shall be embedded in competent material inspected/approved by the geotechnical consultant. Fills -if applicable The on-site soils are suitable for reuse as compacted fill, provided they are free of organic materials, debris, and materials larger than four (4) inches in diameter. After removal of any loose, compressible soils, all areas to receive fill and/or other surface improvements should be scarified to a minimum depth of 12 inches, brought to at least 2 percent over optimum moisture conditions and compacted to at least 90 percent relative compaction (based on ASTM: D1557). If necessary, import soils for near-surface fills should be predominately granular, possess a low or very low expansion potential, and be approved by the geotechnical engineer. Significant grading is not proposed for the proposed additions/remodel. However, if applicable, lift thicknesses of fill should be placed in uniform lifts not exceeding 5 inches. Placement and compaction offill should be in accordance with local grading ordinances under the observation and testing of the geotechnical consultant. We recommend that fill soils be placed at moisture contents at least 2 percent over optimum (based on ASTM: D1557). We recommend that oversize materials (materials over 4 inches) should they be encountered, be stockpiled and removed from the site. Trench Backfill -if applicable The on-site soils may be used as trench backfill provided they are screened of rock sizes over 6 inches in dimension and organic matter. Trench backfill should be compacted in uniform lifts (not exceeding 8 inches in compacted thickness) by mechanical means to at least 90 percent relative compaction (ASTM: D1557). GEOTECHNICAL PARAMETERS The following Geotechnical parameters may used in the design of the proposed remodel structural elements: Foundation Design Structures on properly compacted fill may be supported by conventional, continuous or isolated spread footings. All footings should be a minimum of 30 inches deep (measured in the field below lowest adjacent grade). Interior and perimeter footing widths shall be an minimum 15 inches for the perimeter footings. At these depths, footings founded in fill materials may be designed for an allowable bearing value of 1,750 and 2,250 psf (for dead-plus-live load) for continuous wall Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Beach, CA -Soils Report Project No. JC282. l December 22, 2020 9 and isolated spread footings, respectively. These values may be increased by one- third for loads of short duration, including wind or seismic forces. Reinforcement requirements may be increased if recommended by the project structural engineer. In no case should they be decreased from the previous recommendations. The actual design of the foundation and slabs should be completed by the structural engineer. Cement Type for Concrete in Contact with On-Site Earth Materials Concrete mix design should be based on sulfate testing with Section 1904.2 of the 2019 CBC. Preliminary laboratory testing indicates the site soils possess negligible sulfate exposure. In the event import soils are used, the soils shall be tested for sulfate content and the associated recommendation shall be implemented as follows: ACI 318 BUILDING CODE-Table 19.3.1.1 REQUIREMENTS FOR CONCRETE EXPOSED TO SULFATE-CONTAINING SOLUTIONS Sulfate Water soluble Sulfate (SO,) in Cement Type Maximum water-Minimum fc' , Exposure sulfate (SO,) in soil water, ppm cementitious material normal-weight percent by weight ratio. by weight, normal and light weight weight concrete concrete, psi Negligible 0.00 s so,< 0.10 0 ~ so, <150 ---------------[SO] Moderate 0.10 < SO,< 0.20 150 <so,< 1500 11,IP(MS), 0.50 4000 [S1) IS(MS),P(MS) l(PM)(MS), l(SM)(MS) Severe 0.20 :s; so,< 2.00 1500 <so,< V 0.45 4500 [S2] 10,000 Very Severe SO,> 2.00 SO,> 10,000 V plus 0.45 4500 [S3) pozzalan As a conservative approach, we recommend cement with a min imum strength f'c of 3,000 psi be used for concrete in contact with on-site earth materials. Lateral Load Resistance Footings founded in fill materials may be designed for a passive lateral bearing pressure of 250 pounds per square foot per foot of depth. A coefficient of friction against sliding between concrete and soil of 0.30 may be assumed. Settlement Utilizing the design recommendations presented herein, we anticipate that the Proposed Additions -Cefalia Rcmodd 1740 E Oceanfront, Newport Beach, CA -Soils Report Project No. JC282. l December 22, 2020 10 majority of any post-construction settlement will occur during construction activities. We estimate that the total settlement for the proposed structure will be on the order of 1 inch. Differential settlement is not expected to exceed½ inch in 20 feet. Differential settlement between the new and proposed structures is not expected to exceed ½ -inch. These settlement values are expected to be within tolerable limits for properly designed and constructed foundations. To minimize the potential differential movement we recommend No. 4 bars at 24 inches on- center be doweled to tie7in the existing and new foundations. Interior Slab Moisture Vapor Membrane The existing slab is in good repair and was City-approved and poured in 1995. We recommend the existing slab remain in-place and sealed with a new moisture vapor membrane throughout the first floor living areas (slab on grade). The membrane, to be applied directly atop the living area slab surface, shall provide "anti-microbial protection", which inhibits the growth of bacteria, mold, or mildew. The new moisture vapor membrane should be an approved material (e.g. Sika products), and installed by a qualified flooring contractor. Exterior Slabs-on-grade (Hardscape) -if applicable Concrete slabs cast against properly compacted fill materials shall be a minimum of 4 inches thick (actual) and re inforced with No. 3 rebar at 18 inches on center in both directions. The reinforcement shall be supported on chairs to insure positioning of the reinforcement at mid-center in the slab. Control joints should be provided at a maximum spacing of 8 feet on center in two directions for slabs ahd at 6 feet on center for sidewalks. Control joints are intended to direct cracking. Expansion or felt joints should be used at the interface of exterior slabs on grade and any fixed structures to permit relative movement. Some slab cracking due to shrinkage should be anticipated. The potential for the slab cracking may be reduced by careful control of water/cement ratios. The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to minimize cracking of slabs. Temporary Excavations Based on our recent our review of the plans by ROST Architecture Interiors, the proposed remodel will be sufficiently setback from all property boundaries and hence, temporary shoring will not be required . It is our understanding that the Proposed Additions. Cefalia Remodel 1740 E Oceanfront, Newport Beach, CA -Soils Report Project No. JC282. I December 22, 2020 11 proposed remodel shall not expand the existing footprint of the residence. A geotechnical consultant should be present during the excavation phase of the project to observe the soil conditions and make additional recommendations if necessary. Review of Plans The specifications and parameters outlined in this report shall be considered minimum requirements and incorporated into the Foundation Plans. This office should review the Foundation Plans when available. GEOTECHNICAL OBSERVATION AND TESTING DURING CONSTRUCTION We recommend that a qualified geotechnical consultant be retained to provide geotechnical engineering services, including geotechnical observation/testing, during the construction phase of the project. This is to verify the compliance with the design, specifications and or recommendations, and to allow design changes in the event that subsurface conditions differ from those anticipated. Geotechnical observations/testing should be performed at the following stages: During ANY grading operations, including excavation, removal, filling, compaction, and backfilling, etc After excavations for footings (or thickened edges) and/or grade beams verify the adequacy of underlying materials. If applicable, after pre-soaking of new slab sub-grade earth materials and placement of vapor moisture membranes, prior to pouring concrete. After scoring (tool scouring) of interior slabs prior to pour-over slabs, if applicable. During backfill of drainage and utility line trenches, to verify proper compaction When/if any unusual geotechnical conditions are encountered. Prior to slab pours to ensure proper subgrade compaction and moisture barriers. Please schedule an inspection with the geotechnical consultant prior to the pouring of ALL interior and exterior concrete elements. LIMITATIONS The geotechnical services described herein have been conducted in a manner consistent with the level of care and skill ordinarily exercised by members of the geotechnical engineering profession practicing contemporaneously under similar conditions in the subject locality. Under no circumstance is any warranty, expressed or implied, made in connection with the providing of services described herein. Data, interpretations, and recommendations presented herein are based solely on information available to this office at the time work was performed. EGA Consultants will not be responsible for other parties' interpretations or use of the information developed in this report. The interpolated subsurface conditions should be checked in the field during construction by a representative of EGA Consultants. We recommend that all foundation excavations and grading operations be observed by a representative of this firm to ensure that construction is performed in accordance with the specifications outlined in this report. We do not direct the contractor's operations, and we cannot be responsible for the safety of others. The contractor should notify the owner if he considers any of the recommended actions presented herein to be unsafe. Proposed Additions -Cefalia Remodel 1740 E Oc-eanfront, Newport Beach, CA -Soils Report Project No. JC282. I December 22, 2020 12 REFERENCES 1. "USGS Topographic Map, 7.5 Minute Quadrangle, Newport Beach OE S, California Quadrangle," dated 2018. 2. "Geologic Map of the San Bernardino and Santa Ana 30' X 60' Quadrangles, California," Version 1 0, compiled by Douglas M. Morton and Fred K. Miller, dated 2006. 3. "Geologic Map of California, Santa Ana Sheet," Compilation by Thomas H. Rogers, 1965, fifth printing 1985. 4. "Maximum Credible Rock Acceleration from Earthquakes in California," by Roger W . Reensfelder, dated 1974 5. "Earthquake Hazards Associated with Faults in the Greater Los Angeles Metropolitan Area, Los Angeles County, California, Including Faults in the Santa Monica-Raymond, Verdugo-Eagle Rock, and Benedict Canyon Fault Zones, DMG Open-file Report 79-16," published by the California Department of Conservation, Division of Mines and Geology, dated 1979. 6. "Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada," prepared by California Department of Conservation Division of Mines and Geology, published by International Conference of Building Officials, dated February, 1998. 7. "Guide for Concrete Floor and Slab Construction," by American Concrete Institute, ACI 302.1 R- 04, dated 2004. 8. "California Building Code, California Code of Regulations, Title 24, Part 2," by California Building Standards Commission, 2019. 9. "Seismic Hazard Zone Report for the Newport Beach 7.5-Minute Quadrangles, Orange County, California," by the California Department of Conservation, 1997. 10. "International Building Code, 2015," by the International Code Council, dated June 5, 2014. 11. "Geotechnical Report, Proposed Two-Story, Single Family Residences, 17 40 East Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated September 30, 1994. 12. "Geotechnical Report of Rough Grading, Proposed Single Family Residences, 1740 and 1744 E. Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated December 8, 1994. 13. "Final Soils Report, Interior and Exterior Utility Trench and Retaining Wall Backfill, 17 40 East Oceanfront, Newport Beach, California," by Petra Geotechnical, Inc., dated September 11, 1995. Proposed Additions -Cefalia Remodel 1740 E Oceanfront, Newport Reach, CA -Soils Repon Proj~cl No. JC282. I December 22, 2020 13 Balboa ·,---:..;.> EWPORT BEACH Source: USGS US Topo 7.5-minute map for Newport Beach OE S, CA 2018. EGA SITE LOCATION MAP Consultants 1740 E. OCEANFRONT engineering geotechnical applications NEWPORT BEACH, CALIFORNIA hina Cov Beac -.,. ----1 Corona delMa Project No: JC282.1 Date: DEC 2020 Figure No: 1 - LU u z LU a -V) LU a:: t---z LU u <( -, a <( (.9 z i= V) x UJ l/ - - -I 0 col ..J 0.: PUBLIC BEACH 50' -- $-B-1 EXISTING RESIDENTIAL FOOTPRINT 50' \ _; 0.: - LU u z LU a vi UJ a:: t---z UJ u <( -, a <( (.9 z I -i= 0 V) I co x UJ - EAST OCEANFRONT LEGEND $-GEOTECHNICAL BORING BY EGA CONSULTANTS Reference: "Site Plan, 1740 E Oceanfront, Newport Beach, CA 92661," by John T. Morgan, Jr., Architect, dated January 31, 1995. EGA Consultants engineering geotechnical applications PLOT PLAN 1740 E. OCEANFRONT NEWPORT BEACH, CALIFORNIA Project No: Date: Figure No: JC282.l DEC 2020 2 • • • • • • • • • • f\;:\:ii:,;_''.I Eolian deposits (late Holocene)-Active or recently active L, .. '.:: .. <. · :-, : ._ sand dune deposits; unconsolidated. I: __ •. ·_· ... :: . Om <j Marine deposits (late Holocen~)-Active or recently active . . ... : . ·. • ·_ beach deposits; sand, unconsolidated. I._:-._· 'q'· ---... · __ .. , Estuarine deposits (late Holocene)-Sand, silt, and clay; _'•-'·: . e_s, .. · . unconsolidated, contains variable amounts of organic matter. __ Q_o_p_4 ~I Old paralic deposits, Unit 4 (late to middle Pleistocene)- ..__ __ __,_ Silt, sand and cobbles resting on 34-37 m Stuart Mesa terrace. Age about 200,000-300,000 years. j Old paralic deposits, Unit 3 (late to middle Pleistocene)-~ _ Silt, sand and cobbles resting on 45-46 m Guy Fleming terrace. Age about 320,000-340,000 years. Qomf. I ~Id paralic deposits, Unit 2 (late to middle Pleistocene)- .__ __ ___,_ Silt, sand and cobbles resting on 55 m Parry Grove terrace. Age about 413,000 years. Source: ~ I Old paralic deposits, Unit 1 (late to middle .__ __ __, Pleistocene)-Silt, sand and cobbles resting on 61-63 m Golf Course terrace. Age about 450,000 years. Qop3-6 I Old paralic deposits, Units 3-6, undivided (late to middle ..__ __ __,_ Pleistocene)-Silt, sand and cobbles on 45-55 m terraces. Qopf Old paralic deposits (late to middle Pleistocene) overlain by alluvial fan deposits-Old para lie deposits capped by sandy alluvial-fan deposits. Tes 1 Capistrano Formation (early Pliocene and Miocene)- .._ ___ ] Marine sandstone. Siltstone facies-Siltstone and mudstone; white to pale gray, massive to crudely bedded, friable. Tm Monterey Formation (Miocene)-Marine siltstone and .__ __ ___, sandstone; siliceous and diatomaceous . Morton, D.M., and Miller, F.K. Preliminary Geologic map of the San Bernardino and Santa Ana 30' x 60' quadrangles, California. U.S. Geological Survey. Published 2006.1:100,000scale. EGA Consultants engineering geotechnical applications GEOLOGIC MAP 1740 E. OCEANFRONT NEWPORT BEACH, CALIFORNIA Project No: JC282.1 Date: DEC 2020 Figure No: 3 u s H A R B 0 R s I I ■ Balboa Pier, Newport Beach, CA -Nov 2020 Date High Low (. AM ft PM ft AM ft PM ft Rise Set Moon Sun 8:35 5.6 9:45 3.9 2:33 1.7 3:38 0.1 6:11 5:01 0 Mon 8:59 5.6 10:28 3.6 2:54 2.0 4 :13 0.2 6:12 5:00 Tue 9:25 5.5 11:22 3.3 3:15 2.3 4 :54 0.3 6:13 4:59 0 Wed 9:54 5.3 3:35 2.6 5:42 0.4 6:14 4:59 0 Thu 12:40 3.1 10:29A 5.1 3:53 2.9 6 :43 0.5 6:15 4:58 Fri 11:18 4.8 7:56 0.6 6:16 4:57 0 Sat 12:37 4.5 9 :10 0.5 6:17 4 :56 Sun 4:55 3.8 2:21 4.3 9:14 3.3 10:09 0.4 6:17 4 :55 () Mon 5:15 4.2 3:50 4.4 10:37 2.7 10:57 0.3 6:18 4:55 Tue 5:38 4.7 5:00 4.6 11:32 1.9 11 :38 0.3 6:19 4 :54 () Wed 6:04 5.2 6:00 4.7 12:20 1.1 6:20 4 :53 Thu 6:33 5.7 6:55 4.8 12:16 0.3 1:05 0.3 6:21 4 :53 Fri 7:05 6.2 7:48 4.7 12:53 0.5 1 :51 -0.4 6:22 4 :52 Sal 7:39 6.6 8:41 4.6 1:30 0.8 2:37 -0.9 6:23 4 :51 Sun 8:16 6.8 9:35 4.3 2:07 1.2 3:24 -1.2 6:24 4 :51 Mon 8:54 6.8 10:33 4.0 2:46 1.6 4 :14 -1 .2 6:25 4 :50 Tue 9:36 6.5 11:39 3,8 3:27 2.0 5:07 -1.0 6.26 4:50 • Wed 10:21 6.0 4:12 2.4 6:06 -0.7 6:27 4:49 Thu 12:57 3.6 11:14A 5.4 5:08 2.8 7:11 -0.3 6:28 4:49 Fri 2:27 3.7 12:20 4.8 6:33 3.1 8:20 0.1 6:29 4:48 Sat 3:44 4.0 1:46 4.3 8:34 3.1 9:27 0.3 6:30 4:48 Sun 4:38 4.2 3:19 4.0 10:17 2.7 10:24 0.5 6:30 4:47 C) Mon 5:16 4.5 4:36 3.9 11:24 2.2 11:09 0.7 6:31 4:47 Tue 5:46 4.8 5:38 3.9 12:11P 1.6 . 11:46 1.0 6:32 4 :47 0 Wed 6:10 5.0 6:28 3.9 12:49 1.1 6:33 4:46 Thu 6:33 5.3 7:12 3.8 12:17 1.2 1:22 0.7 6:34 4:46 Fri 6:54 5.5 7:51 3.8 12:43 1.4 1:53 0.3 6:35 4:46 Sat 7:16 5.6 8:30 3.7 1:09 1.7 2 :24 0.0 6:36 4:46 Sun 7:40 5.8 9:08 3.7 1:34 1.9 2 :55 ~0.2 6:37 4:46 Mon 8:06 5.8 9:49 3.6 1:59 2.0 3:29 ~o.3 6:38 4:45 0 EGA TIDAL CHART Project No: JC282.1 Consultants 1740 E. OCEANFRONT Date: DEC 2020 NEWPORT BEACH, CALIFORNIA Figure No: 4 engineering geotcchnical applications APPENDIX A Geologic Logs LOG OF EXPLORATORY BORING Sheet 1 of 1 Job Number: JC282.1 Boring No: B-1 Project: 1740 E. Oceanfront, Newport Beach, CA Boring Location: See Figure 2 Cefalia Remodel Date Started: 11/17/2020 Rig: Mob. 4" augers Date Completed: 11/17/2020 Grnd Elev. +/-13 ft. NAVD88 Sample -J!. 'tl Direct Type X 0. Shear n> C: 'tl Ql ~ (f) ■ThinWall 1ZJ 2.5"Ring 0. ,:, I- Ql Ql Ql ~ .!:: 'iii (f) LL. 0. ,:, Tube Sample C: C: .... w >-Ql 0 C: Ql (/) I-.!: I--e (/) 0 0 0 0. -"' (.) C: ·;;; -G-O'. .c ·o ::, "5 [Z] Bulk [D standard Spilt ~ Static Water ~ Ql E (.) w 0.. in 0 C: Ql (f) 'o Ill Sample Spoon Sample Table ::, ro ::, I 0 in ~ 0. E I-C: X ::> ·o 0 w ·x 0 ~ ro C/"\11 nc:cre>IPT lnN ~ I FILL: Light gray brown, poorly graded fine sand 1 SP with shell fragments, trace rootlets, Opt% :>< drv to moist, medium dense. , 5.0 101.4 111 .0 31.0 18 13.5% At 3 ft.: Becomes tan brown, fine sand with Sulf SP t2:: trace shell fragments, dry to damp, cohesionless, 4.0 29ppm 5 -medium dense to dense. SP tz At 6 ft.: Fine-to mediu-grained sand, micaceous, 4.6 z slightly moist, medium dense to dense. SP At 8 ft. Poorly sorted sand, medium to coarse, 3.8 grained, medium dense becoming dense. 10 -v 7 At 10.5 ft.: Very moist to saturated, dense. 11.2 At 11 ft.: Groundwater encountered. Total Depth: 12.0 ft. Groundwater at 11 ft. 15 -No Caving Backfilled and Compacted 11/17/2020 20 - '. I,. i ~ , ~-... : 25 --Y~r ~·~ 30 - 35 - 40 I EGA Consultants II ,:,;· I APPENDIX 8 Laboratory Results GEOLOGY· GEOTECH · GROUNDWATER EGA Consultants 375-C Monte Vista Avenue Costa Mesa, California 92627 Attention: Subject: Mr. David Worthington, C.E.G. Laboratory Test Results 17 40 East Oceanfront Newport Beach, California Dear Mr. Worthington: December 2, 2020 Project No. 114-651-10 G3SoiIWorks, Inc. performed the requested laboratory tests on the soil specimens delivered to our office for the subject project. The results of these tests are included as an attachment to this report. We appreciate the opportunity of providing our services to you on this project. Should you have any questions, please contact the undersigned. Sincerely, G3Soi1Works, Inc. ··, \ By: ~~'..u~~==~~~ . ' ,rector o Engineering -- Attachment: Laboratory Test Results 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com EGA Consultants Laboratory Test Results 17 40 East Oceanfront Newport Beach, California December 2, 2020 Project No. 114-651-10 Page 2 of 3 LABORATORY TEST RESULTS Summarized below are the results of requested laboratory testing on samples submitted to our office. Dry Density and Moisture Content Tabulated below are the requested results of field dry density and moisture contents of undisturbed soils samples retained in 2.42-inch inside diameter by 1-inch height rings. Moisture only results were obtained from small bulk samples. Sample Dry Density Moisture Content Identification (pcf) (%) B-1@ 2.5' 101.4 5.0' B-1 @ 4.0' * 4.0 B-1 @ 6.0' * 4 .6 B-1@ 8.0' * 3.8 B-1@ 10.0' * 11 .2 Notes: (*) Denotes small bulk sample for moisture content testing only. Soil Classification Requested soil samples were classified using ASTM D2487 as a guideline and are based on visual and textural methods only. These classifications are shown below: Sample Identification Soil Description Group Symbol B-1@ 0-3' Poorly graded sand with shells and SP rootlets -light olive brown B-1 @ 6' Poorly graded sand -brown SP Maximum Dry Density and Optimum Moisture Content Maximum dry density and optimum moisture content test was performed on the submitted bulk soil samples in accordance with ASTM D 1557. The results are shown below: Sample Identification Maximum Dry Density Optimum Moisture (pcf) Content(%) B-1 @ 0-3' 111 13.5 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com EGA Consultants Laboratory Test Results 17 40 East Oceanfront Newport Beach, California Sulfate Content December 2, 2020 Project No. 114-651-10 Page 3 of 3 A selected bulk sample was tested for soluble sulfate content in accordance with Hach procedure. The test result is shown below: Sample Identification Water Soluble Sulfate in Soil Sulfate Exposure (PPM) (ACI 318-08, Table 4.2.1) B-1@ 0-3' 29 so Direct Shear The results of direct shear testing (ASTM D3080) are plotted on Figure S-1 . Soil specimens were soaked in a confined state and sheared under varied loads ranging from 1.0 ksf to 4.0 ksf with a direct shear machine set at a controlled rate of strain of 0.01 inch per minute. 350 Fischer Ave. Front • Costa Mesa. CA 92626 • P: 714 668 560 0 • www.G3Soi1Works.com 4,000 3,750 3,500 3,250 3,000 2,750 LL 2,500 (/) a.. Cl) 2,250 (/) w 0::: 2,000 I-en 0::: <( 1,750 w I en 1,500 1,250 1,000 750 500 250 0 0 symbol boring • B-1 500 1,000 DIRECT SHEAR TEST Undisturbed 1,500 2,000 2,500 NORMALSTRESS,PSF 3,000 3,500 4,000 17 40 East Oceanfront, Newport Beach COHESION 18 psf. depth (ft.) symbol boring depth (ft.) 2.5 FRICTION ANGLE 31 .0 degrees FIGURE S-1 DIRECT SHEAR TEST PN: 114-651-10 REPORT DATE: 12/02/20 350 Fischer Ave Front Costa Mes<1. CA 92626 Phona: (714) 668 5600 www.G3So,1Workscom FIG. S-1 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com APPENDIX C USGS Design Maps Detailed Report L\TC Hazards by Location Search Information Address: Coordinates: Elevation: Timestamp: 1740 E Oceanfront, Newport Beach, CA 92661, USA 33.5965103, -117.8875953 17 ft 2020-12-03T15:23:03.6272 V iji, v Anaheim 17ft Long Beacho Catalina Island Essential Fish Habitat... .e ~ Riverside 0 Temecula 0 ij Hazard Type: Seismic Go gle Cle Natio, Map data ©2020 Google, INEGI Reference Document: ASCE7-16 Risk Category: Site Class: II D-default Basic Parameters Name Value Ss 1.377 S1 0.488 SMs 1.653 SM1 • null Sos 1.102 So1 • null * See Section 11.4.8 Description MCER ground motion (period=0.2s) MCER ground motion (period=1.0s) Site-modified spectral acceleration value Site-modified spectral acceleration value Numeric seismic design value at 0.2s SA Numeric seismic design value at 1.0s SA •Additional Information Name Value Description soc • null Seismic design category Fa 1.2 Site amplification factor at 0.2s Fv * null Site amplification factor at 1.0s CRs 0.906 Coefficient of risk (0.2s) CR1 0.92 Coefficient of risk (1 .0s) PGA 0.603 MCEG peak ground acceleration FPGA 1.2 Site amplification factor at PGA PGAM 0.724 Site modified peak ground acceleration TL 8 SsRT 1.377 SsUH 1.52 SsD 2.624 S1RT 0.488 S1UH 0.531 S1D 0.819 PGAd 1.056 * See Section 11.4.8 Long-period transition period (s) Probabilistic risk-targeted ground motion (0.2s) Factored uniform-hazard spectral acceleration (2% probability of exceedance in 50 years) Factored deterministic acceleration value (0.2s) Probabilistic risk-targeted ground motion (1.0s) Factored uniform-hazard spectral acceleration (2% probability of exceedance in 50 years) Factored deterministic acceleration value (1.0s) Factored deterministic acceleration value (PGA) The results indicated here DO NOT reflect any state or local amendments to the values or any delineation lines made during the building code adoption process. 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