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HomeMy WebLinkAboutPA2021-055_20210310_Geotechnical Investigation_12-14-20consultants GEOTECHNICAL INVESTIGATION FOR PROPOSED SINGLE FAMILY DWELLING LOCATED AT 1 COLLINS ISLAND NEWPORT BEACH, CALIFORNIA Presented to: JON & KARIS GROSS 4639 S. Lindhurst Avenue Dallas, TX 75229 clo: Sinclair Associates Architects Attn: Robert Sinclair, AIA 10956 Weyburn Avenue, Studio 200 Westwood Village, CA 90024 Prepared by: EGA Consultants, Inc. 375-C Monte Vista Avenue Costa Mesa, California 92627 ph (949) 642-9309 fax (949) 642-1290 December 14, 2020 Project No. RS276.1 engineering geotechnical applications 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • FAX (949) 642-1290 PA2021-055 consulta nts engineering geotechnical applications December 14, 2020 Project No. RS276.1 Site: Proposed Residential Development: 1 Collins Island Newport Beach (Collins Island}, California 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 development is 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 re-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 of Newport Beach requirements. Foundation specifications herein include added provisions for potential liquefaction on-site per City policy CBC 1803.11-12. SUMMARY OF RECOMMENDATIONS Design Item Mat Slab Fo undation: Mat Slab Bearing Pressure: Footing Bearing Pressure Conventional: Passive Lateral Resistence: Coefficient of Friction: Soil Expansion: Soil Sulfate Content: Building Pad Over-Excavation: Sandy Soil Max. Density: Recommendations min. 12 inches with thickened edges ( + 6 inches) with no. 5 bars@ 12" o.c. each way, top and bottom 1,000 psf 1,750 psf -building, continuous; 2,250 psf -pad footings 250 psf per foot 0.30 Non-Expansive, Cohesionless Beach Sands Negligible min. 2½ ft. below ex. grade, +6" scarify & treat bottom 108.0 pct@ 12.0 % Opt. Moisture * Concrete building slabs shall be underlain by 2" clean sand, underlain by a min. 15 mil thick vapor barrier, with all laps sealed, underlain by 4" of ¾-inch gravel (capillary break). Seismic Values (per CBC 2019, ASCE 7-16 -Equivalent Lateral Force Methods): Site Class Definition (Table 1613.5.2) D Mapped Spectral Response Acceleration at 0.2s Period, s. 1.388 g Mapped Spectral Response Acceleration at 1s Period, S, 0.493 g Short Period Site Coefficient at 0.2 Period, Fa 1.2 Long Period Site Coefficient at 1 s Period, F v 1. 8 Adjusted Spectral Response Acceleration at 0.2s Period, SMs 1.666 g Adjusted Spectral Response Acceleration at 1 s Period, SM1 0.887 g Design Spectral Response Acceleration at 0.2s Period, S05 1.110 g Design Spectral Response Acceleration at 1s Period, S0, 0.592 g PGAm = 0.729 g Note: EGA Consultants recommends the structural engineer review and confirm associated seismic values for the proposed residential development. 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • FAX (949) 642-1290 PA2021-055 consultants engineering geotechnical applications MR. JON GROSS c/o: Sinclair Associates Architects 10956 Weyburn Avenue, Studio 200 Westwood Village, CA 90024 December 14, 2020 Project No. RS276.1 Attn: Robert Sinclair, AIA Subject: GEOTECHNICAL INVESTIGATION FOR PROPOSED RESIDENTIAL DEVELOPMENT LOCATED AT 1 COLLINS ISLAND NEWPORT BEACH, CALIFORNIA Dear Team, In accordance with your request and with the 2019 CBC, we have completed our Geotechnical Investigation of the above referenced site. This investigation was performed to determine the site soil conditions and to provide geotechnical parameters for the proposed re-grading and construction at the subject site. It is our understanding that the proposed re-development shall include the demolition of the existing residence and the construction of a new residential dwelling with associated improvements. This report presents the results of the investigation (including Liquefaction Computations) along with grading and foundation recommendations pertaining to the development of the proposed residential development. 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 Prine· I Engineering Geologist/CEO s JOHN F. EGGERS Staff Geologist cc: (3) Addressee " Sr. Proj 375-C Monte V ista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • PAX (949) 642-1290 PA2021-055 GEOTECHNICAL INVESTIGATION December 14, 2020 Project No. RS276.1 FOR PROPOSED RESIDENTIAL DEVELOPMENT LOCATED AT 1 COLLINS ISLAND NEWPORT BEACH, CALIFORNIA INTRODUCTION In response to your request and in accordance with the City of Newport Beach Building Department requirements, we have completed a preliminary geotechnical investigation at the subject site located at 1 Collins Island, in the City of Newport Beach (Collins Island), State of Californ ia (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 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 STU DY The scope of our investigation included the following tasks: • Review of read ily available published and unpublished reports; • Geologic reconnaissance and document research; • Excavation and sampling of two (2) exploratory borings to a total depth of 10 feet below existing grade (b.g.); • Continuous Cone Penetration Test (CPT) sounding to a depth of 45½ feet below grade (results of the CPT sounding are included herein); • Laboratory testing of representative samples obtained from the exploratory borings; • Engineering and geologic analysis including seismicity coefficients in accordance with the 2019 California Building Code (CBC); • Seismic and Liquefaction analysis and settlement computations (in accordance with California Geological Survey, SP 117A); • Preparation of this report presenting our findings, conclusions, and recommendations. 2 PA2021-055 GENERAL SITE CONDITIONS The subject property is an approximate 72 ft. wide by 85 ft. long, wedge-shaped lot located at 1 Collins Island within the City of Newport Beach, County of Orange. The subject site is located in the central portion Collins Island, within the Newport Bay. For the purpose of clarity in this report, the island is located in the southeastern portion of Collins Island within the central portion of Newport Bay. The bayfront lot is located approximately 2,800 feet northeast of the Pacific Ocean, across the Balboa Peninsula (see Site Location Map, Figure 1 ). The subject lot consists of a relatively flat, planar lot with no significant slopes on or adjacent to the site. Based on our review of the building plans, the lot is approximately 6,772 sq. ft. and the building area is roughly 3,457 sq. ft. Currently, the lot is occupied by a two-story residence situated on a graded level pad. An attached three-car garage is located along the north property line and is accessed by the rear alley. All structures are supported on continuous perimeter footings with slab-on-grade floors. The site is legally described as Lot 1 of Tract No. 1723 (APN 050-010-06). The existing property layout is shown in the Plot Plan, Figure 2, herein. PROPOSED RESIDENTIAL DEVELOPMENT Based on preliminary review of the architectural plans by Sinclair Associates Architects, the proposed residential development shall include the demolition of the existing structures, and the construction of a new two-story, single family dwelling with a roof top deck. The proposed residential construction shall include an attached two-car garage. 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. It is our understanding that the grade of the site is not expected to vary significantly. Based on the digital elevation model by NOAA National Centers for Environmental Information (NCEI -NAVD88, Last Modified September 23, 2016), the site elevation is approximately 9 ft. above MSL (see reference No. 10). Based on the preliminary plans, the proposed finish floor elevation shall be 9+ ft. above mean sea level (MSL) to I Collins Island, Newport Beach (Collins Island), CA Soils Report -Proposed Residence Project No RS276. I Oecember 14, 2020 3 PA2021-055 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. No basement or retaining walls are planned . SUBSURFACE EXPLORATION Our subsurface exploration consisted of the excavation of two (2) exploratory borings (B-1 and B-2) to a maximum depth of 10 feet below grade (b.g.) and one CPT probe (CPT-1) to a depth of 45½ b.g. (continuous soil profile). Representative bulk and relatively undisturbed soil samples were obtained for labora- tory testing. Geologic/CPT logs of the soil boring/probes are included in Appendix A. The borings were continuously logged by a registered geologist from our firm who obtained soil samples for geotechnical laboratory analysis. The approximate locations of the borings are shown on Figure 2 (Plot Plan). Geotechnical soil samples were obtained using a modified California sampler filled with 2 3/a 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: * Dry Density and Moisture Content (ASTM: D 2216) * Soil Classification (ASTM: D 2487) * Direct Shear (ASTM: D 3080) l Collins Island, Newport Beach (Collins Island). CA Soils Report -Proposed Residence ProJect No. RS276. I December 14, 2020 4 PA2021-055 * Maximum Dry Density and Optimum Moisture Content (ASTM: D 1557) * Sulfate Content (CA 417, ACI 318-14) All laboratory testing was performed by our sub-contractor, G3SoiIWorks, Inc., of Costa Mesa, California. Geotechnical test results are included in Appendix B, herein. SOIL AND GEOLOGIC CONDITIONS The site soil and geologic conditions are as follows: Seepage and Groundwater According to the Orange County Water District (OCWD), there are no water wells located within the general vicinity of the subject property. The Newport Bay is located approximately 5 feet to the south of the waterfront lot, and the Pacific Ocean is located approximately 2,800 feet to the southwest, across the Balboa Peninsula. Seepage or surface water ponding was not noted on the subject site at the time of our study. Our data indicates that the groundwater encountered is subject to significant tidal fluctuations. Groundwater was encountered in our test excavation at depth of approximately 6½ feet below grade. Based on our review, the groundwater highs approach the tidal highs in the bay, and groundwater lows drop slightly below mean sea level. From a construction standpoint, any excavations advanced down to within the tidal zones should be expected to experience severe caving. A tidal chart for the month of November 2020, is presented as Figure 4, herein. Collins Island and Balboa Island Topography and Bathymetry Elevations across the greater Balboa Island range from approximately 8 feet along the bulkhead lines at the seawall perimeters; ascending to almost 13 feet near the central backbone of the Island. Significant raising of the greater and Balboa and Collins Island seawalls to an elevation of 1 O+ ft. above MSL is underway since 2016. Common area sandy beaches have been groomed and re-groomed with import sands which feather gently to the bay waters. From the bulkhead and beach shorelines, the nearshore bay floors generally I Collins Island, Newport Beach (Collins Island}, CA Soils Report -Proposed Residence Project o. RS276. I December 14, 2020 5 PA2021-055 dereends at an inclination of appmxim<llte~, 10:1 {horizontal to vertical), down to appro1timate elevations of ~ 10 to ~ 12 feet along ~he channel limit line {depending on tidal fluctuations). Similar tc surrom,ding islands in the Newport Bay {e.g. Linda tsle, Bay Island. and Udo Js!ancl)1 Balboa Island's (includes Collins and little Bslbaa) surff.ice is primari$y m1:srHnade (graded approx. 10 fl. above the high..-tide zone i11 the 1920's}. However, the island feetura is located on a naturaHy--formed, subaqueous, back-barrier coastal landmass. It is situated on the landward skie of a coastal bar fonned by a transgress~ve sea and littorai c-,mrents at the seaward edge of a stream delta or lagoon. The Mev-1port Bay coastal estuary was originaHy foTTOOd as the lower reach of the Santa Ana Rtver. However, in 1'915. due to severe silting that resulted from flooding of the Santa Ana River (and also the construction of man-made channel). the Santa Ana River \WS stru!..1ural!y real!gned. Coooeql~entiy, the. Newport Ba~/ is r,;urrentfy fed only by the San rnego Gteek _which dmii1s a comparatively small area. The· mouth of the San Diego ·creak is lot."S!ted at the Jamboraa Road bridge roughly 5½ kil<lmeters northeast of the subject site (Upper Back 8ay). Geologic Settir1g 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 Coastal Plain is bound by the Tustin Plan and 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 marine (Qes)/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 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 East Pacific Coast Highway and Bayside Avenue, less than ½ kilometers north of the site (Dover Shores bluffs). A Geologic Map is presented as Figure 3, herein (reference: Morton, D.M., and I Collins Island, Newport Beach (Collins Island), CA Soils Report -Proposed Residence Project No. ){$276 I IJcccmbcr 14, 2020 6 PA2021-055 Miller, F.K., 2006). Based on the geologic map (Figure 3) correlation with the nearby CPT probe advanced on February 15, 2016, bedrock of the Monterey Formation (Tm) was likely encountered approximately 34 feet below grade. Faulting A review of available geologic records indicates that no active faults cross the subject property (reference No. 2, and Figure No. 3). Seismicity The seismic hazards most likely to impact the subject site is ground shaking following a large earthquake on the Newport-Inglewood (onshore), Palos Verdes (offshore), San Joaquin Hills Blind Thrust, Whittier-Elsinore, or Cucamonga Faults. The site is primarily underlain by fill and beach sands with thin layers of silt/clay. 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/building specifications outlined in this report are in part, intended to mitigate seismic shaking. Based on our review of the "Seismic Zone Map," issued by the State of California, there are no mapped earthquake landslide zones on the site. The proposed development shall be designed in accordance with seismic requirements contained in the 2019 CBC as adopted by the City of Newport Beach building codes. 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 7-16 Standard), the site shall be designed using the following seismic parameters: 2019 CBC Seismic Design Parameters (Equivalent Lateral Force Method) SITE ADDRESS I C II" I I d N B I C o ms s an , ewport eac 1, Site Latitude (Decimal Degrees) Site Longitude (Decimal Degrees) I Collins Island, Newport Beach (Collins Island), CA Soils Report -Proposed Residence Project 0, RS276 I Dect:mber 14. 2020 A 33.608270087 -117.900266288 PA2021-055 Site Class Definition D Mapped Spectral Response Acceleration at 0.2s Period, S5 1.388 g Mapped Spectral Response Acceleration at Is Period, S1 0.493 g Short Period Site Coefficient at 0.2 Period, Fa 1.2 Long Period Site Coefficient at Is Period, Fv 1.8 Adjusted Spectral Response Acceleration at 0.2s Period, SMs 1.666 g Adjusted Spectral Response Acceleration at Is Period, SM, 0.887 g Design Spectral Response Acceleration at 0.2s Period, S05 1.110g Design Spectral Response Acceleration al Is Period S01 0.592 g In accordance with the USGS Design Maps, and assuming Site Class "D", the mean peak ground acceleration (PGAm) per USGS is 0.729 g. The stated PGAm is based on a 2% probability of exceedance in a 50 year span (see copies of the USGS Design Maps Detailed Report, Appendix D, herein) EGA Consultants recommends the structural engineer review and confirm associated seismic values for the proposed residential development. FINDINGS Subsurface Soils As encountered in our test borings, the site is underlain by hydraulic fill sands and native materials as follows: Fill (Af) Fill sands were encountered in each of the borings to a depth of approximately 3 feet below ground. The fill soils consist generally of light to dark brown, dry to moist, loose to medium dense, fine-grained sand with shell fragments and organics. The expansion potential of the fill soils was judged to be "non-expansive" when exposed to an increase in moisture content. Hydraulic-Native Sands (Qm). Paralic Deposits {Qop) and Bedrock (Tm) The fill materials are hydraulic and native sands as encountered in each of the test borings (B-1 , B-2, and CPT-1 ). The native sands consist generally of medium to dark brown, moist to saturated, medium dense, non- cemented, fine-grained, silty sand and sandy clay with trace shell I Coll111s Island, Ne"pon Beach (Collin, Island). CA Soils Rcpon • Propo,cd Residence ProJ<::" o RS276 I December 14. 2020 8 PA2021-055 fragments. The native sands are underlain by marine sands (Qm) 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 to the maximum depths explored (45½ ft. b.g.). Based on the geologic map (Figure 3) correlation with the on-site CPT probe advanced on February 15, 2016, bedrock of the Monterey Formation (Tm) was likely encountered approximately 34 feet below grade. Based on the laboratory results dated December 4 , 2020, the site maximum dry density is 108.0 pcf at an optimum moisture content of 12.0% (per ASTM D 1557). The complete laboratory reports are presented in Appendix B, herein. LIQUEFACTION ANALYSIS (Per SP117 A) Liquefaction of soils can be caused by strong vibratory motion in response to earthquakes. Both research and historical data indicate that loose, granular sandy soils are susceptible to liquefaction, while the stability of rock, gravels, clays, and silts are not significantly affected by vibratory motion. Liquefaction is generally known to occur only in saturated or near saturated granular soils. The site is underlain by fill/eolian sands, old paralic deposits, and bedrock of the Monterey Formation. It is our understanding that the current City policy, has assigned a seismic settlement potential of one (1.0) inch in the upper ten feet, and three (3.0) inches for soil depths of ten to fifty feet. In the event settlement values exceed these threshold values, then additional analysis and/or additional mitigation is required. The CPT testing was performed in accordance with the "Standard Test Method for Performing Electronic Friction Cone and Piezocone Penetration Testing of Soils," (ASTM D5778-12). The seismically induced settlement for the proposed structure was evaluated based on the "Soil Liquefaction During Earthquakes" by I.M. Idriss and R.W. Boulanger, dated September 8, 2008. The analysis was provided by two 10-feet deep 4 " diameter hand-auger borings, and a 45+ feet deep 1.7" diameter CPT probe advanced on February 15, 2016. The exploratory borings and probe locations are shown in the Plot Plan, Figure 2, herein. The soil borings were continuously logged by a certified engineering geologist of I Collins Island. Newpon Beach (Collins Island), CA Soils Report -Propu~cd Residence Project No. RS276.1 Oecembt:r 14, 2020 9 PA2021-055 our firm. The computations and results of our Liquefaction Analysis, based on CPT blow counts of Boring CPT-1 , are attached in Appendix D, herein. The seismically induced settlement analysis was evaluated based on methods published in the references Nos. "a" through "j" (see "Associated References", herein). The liquefaction and seismic settlement calculations indicate seismic settlement (includes dry and saturated sands) in the upper 50 feet is less than 2.5 inches, and in the upper 10 feet is less than 1.0 inch (post soil cement treatment -see Page 5 of Plate A) and hence shallow mitigation methods for liquefaction may be implemented per City Code Policy (No. CBC 1803.5.11-2 last revised 7/3/2014). Based on our liquefaction analysis, and in accordance with the City of Newport Beach Policy No. CBC 1803.5.11-12 (NBMC, Chapter 15), we recommend the following mitigative methods to minimize the effects of shallow liquefaction: a. Remedial Grading via Soil Cement in Upper 3 feet -See Page 11 , below b. Mat Slab Foundation -see Page 12, below The soil densification via soil cement and the mat slab foundation specifications outlined below will act to decrease the potential settlement due to liquefaction and/or seismically induced lateral deformation to tolerable amounts. The above specifications eliminate the use of piles and associated construction vibrations and groundwater displacement induced by caisson drilling or pi le-driving. If the above specifications are incorporated, the proposed structure shall be stable and adequate for the intended uses and the proposed construction will not adversely impact the subject or adjacent properties. Other Geologic Hazards Other geologic hazards such as landsliding, or expansive soils, do not appear to be evident at the subject site. 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. I Collms Island. Newport 13each (Collins Island). CA Soils Report -Proposed Residence Project No. RS276. I L)ecember 14, 2020 10 PA2021-055 RECOMMENDATIONS The following sections discuss the principle geotechnical concerns which should be considered for proper site re-development. Earthwork Grading and earthwork should be performed in accordance with the following recommendations and the General Earthwork and Grading Guidelines included in Appendix C. It is our understanding that the majority of grading will be limited to the re-grading of the building pad for the proposed construction. In general, it is anticipated that the removal of the upper 2½ feet (plus 6 inches of scarification) within the building footprint (slab-on-grade portion) will require removal and recompaction to prepare the site for construction. The removals should be accomplished so that all fill and backfill existing as part of the previous site use and demolition operations are removed. Where feasible, the limits of the pad fill shall be defined by a 3 foot envelope encompassing the building footprint. Care should be taken to protect the adjacent property improvements. A minimum one foot thick fill blanket should be placed throughout the exterior improvements (approaches, parking and planter areas). The fill blanket will be achieved by re-working (scarifying) the upper 12 inches of the existing grade. Remedial Grading -Soil Cement Due to in situ granular, cohesionless sands, we recommend a minimum three (3) pallets (40 bags dry mix, each weighing 94 pounds and approximately 1.33 cubic yards) of Portland cement be blended into the newly-placed fill. The first application of the Portland Cement shall be placed on the bottom of the scarified over-excavation(s). This option may be eliminated or reduced if suitable import fills are trucked-in. Site Preparation Prior to earthwork or construction operations, the site 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. A minimum of 3 feet of the soils below existing grade will require removal and recompaction in the areas to receive building pad fill. Following removal and scarification of 6 inches, the excavated surface should be inspected by the soils engineer or his designated representative prior to the placement of any fill in footing trenches. Holes or pockets of I Collins Island, Newport Beach (Collins Island), CA Soils Report • Proposed Residence PrOJCCI No. RS276. I Dc::~~mber 14, 2020 11 PA2021-055 undocumented fill resulting from removal of buried obstructions discovered during this inspection should be filled with suitable compacted fill. Fills 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: D 1557). If necessary, import soils for near-surface fills should be predominately granular, possess a very low expansion potential, and be approved by the geotechnical engineer. Lift thicknesses will be dependent on the size and type of equipment used. In general, fill should be placed in uniform lifts not exceeding 6 inches. Placement and compaction of fill 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: D 1557). We recommend that oversize materials (materials over 4 inches) should they be encountered, be stockpiled and removed from the site. Trench Backfill The on-site soils may be used as trench backfill provided they are screened of rock sizes over 4 inches in dimension and organic matter. Trench backfill should be compacted in uniform lifts (not exceeding 6 inches in compacted thickness) by mechanical means to at least 90 percent relative compaction (ASTM: D 1557). Geotechnical Design Parameters The following Geotechnical parameters may used in the design of the proposed structure (also, see "Liquefaction Analysis" section, above): Mat Foundation Design Mat slabs founded in compacted fill or competent native materials may be designed for an allowable. bearing value of 1,000 psf (for dead-plus-live load). These values may be increased by one-third for loads of short duration, including wind or seismic forces. The actual design of the foundation and slabs I Collins Island, Newport Reach (Collins Island), CA Soils Report -Propost:d Rt:sidenct: Project No. RS276. I December 14, 2020 12 PA2021-055 should be completed by the structural engineer. MIN. DESIGN ITEM Mat foundations: allowable bearing pressure: passive lateral resistence: mat slab thickness: steel reinforcement: coefficient of friction: Modulus of Subgrade Reaction: RECOMMENDATIONS 1,000 psf 250 psf per foot min. 12 inches with thickened edges ( + 6 inches) no. 5 bars @ 12" o.c. each way, top and bottom 0.30 ks = 90 lbs/in3 The mat slab shall be directly underlain by a min. 2-inch thick layer of washed sand, underlain by min. 15-mil stego wrap (or equiv., lapped and sealed), underlain by 4 inches of gravel (¾-inch crushed rock), underlain by competent native materials (see "Capillary Break Section below). For mat slabs, we do not recommend expansion or felt joints be used. Reinforcement requirements may be increased if recommended by the project structural engineer. In no case should they be decreased from the previous recommendations. Capillary Break Below Interior Slabs In accordance with the 2016 California Green Building Standards Code Section 4.505.2.1, we provide the following building specification for the subject site (living area and garages slabs): Concrete building slabs shall be directly underlain by a min. 2 inches of clean/washed sand , underlain by a min.15 mil-thick moisture barrier (e.g. "Stego Wrap"), with all laps sealed, underlain by 4 inches of¾ -inch gravel. We do not advise placing sand directly on the gravel layer as this would reverse the effects of vapor retardation (due to siltation of fines). The above specification meets or exceeds the Section 4.505.2.1 requirement. Conventional Foundations (outside the mat slab, if applicable) For potential (though unlikely) auxiliary structures outside the mat slab, if applicable, on properly compacted fill: all continuous or isolated pad footings should be a minimum of 24 inches deep (measured in the field below lowest adjacent grade). Footing widths shall me an minimum 15 inches. At this depth (24 inches) 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 I Collin~ Island, Newport Beach (Collins Island), CA Soils Repon -Proposed Residence Project No. RS276. I December 14, 2020 13 PA2021-055 continuous wall and isolated spread footings, respectively. These values may be increased by one-third for loads of short duration, including wind or seismic forces. If applicable, continuous perimeter footings should be reinforced with No. 5 rebar (two at the top and two at the bottom). Reinforcement requirements may be increased if recommended by the project structural engineer. In no case should they be decreased from the previous recommendations. 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. We recommend that a slipsheet (or equivalent) be utilized if crack-sensitive flooring is planned directly on concrete slabs. All slabs should be designed in accordance with structural considerations. 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 (in the event of soil import, soils shall be tested a specified accordingly). Preliminary laboratory testing indicates the site soils possess negligible sulfate exposure. 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 <so,< 0.10 0 :5 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, and due to the marine environment, we recommend cement with a minimum strength f'c of 3,000 psi be used for concrete in contact with on-site earth materials. Settlement Utilizing the design recommendations presented herein, we anticipate that the I Collins Island, Newport lk-ach (Coll ins Island), CA Soils Report -Proposed Residence Project No. RS2 76.1 l)ecember 14, 2020 14 PA2021-055 majority of any post-grading 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 over 30 feet. These settlement values are expected to be within tolerable limits for properly designed and constructed foundations. 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. Exterior Slabs-on-grade (Hardscape) Concrete slabs cast against properly compacted fill materials shall be a minimum of 4 inches thick (actual) and reinforced 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 and 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. Please call the geotechnical consultant prior to placing steel and to the pouring of all exterior slabs. Surface Drainage Surface drainage shall be controlled at all times. Positive surface drainage should be provided to direct surface water away from structures and toward the street or suitable drainage facilities. Ponding of water should be avoided adjacent to the structures. Recommended minimum gradient is 2 percent for unpaved areas and one percent for concrete/paved areas. Roof gutter discharge should be directed away from the building areas through solid PVC pipes to suitable discharge points. Area drains should be provided for planter areas and drainage shall be directed away from the top of slopes. I Collins Island, Newpon Reach (Coll111s Island), CA So1b Rcpon • Proposed Residence PruJCCI No. RS276. I December 14. 2020 15 PA2021-055 The specrflc .. ~tions and parameters. outlined in tnis report sh~tf be cons.idor~d minimum requicrjrm.1niz ~nd im;cnporat<:Ki into the Grading, and Foundation Plani if applicable. This t:ffice shouid review the Ptam; when avaitaibie. If approved, the geotectmk:c1t com.mlfamt shall sign/st~m,, the app!icabie Plans from ai g~otschnical standpoint I ..::Gi!i:>.S ls!<!Xd., Newport Be.ecb (CnlHns l~lll.mJ). CA Soil~ /teport -Proi,...sro R.r..slde;,.-;e l'roj::~ 'Nv. !U,276 l Deceiii!Jer M, 2020 PA2021-055 PRE-CONSTRUCTION MEETING It is recommended that no clearing of the site or any grading operation be performed without the presence of a representative of this office. An on site pre-grading meeting should be arranged between the soils engineer and the grading contractor prior to any construction. 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. • After pre-soaking of new slab sub-grade earth materials and placement of capillary break, plastic membrane, prior to pouring concrete. • During backfill of drainage and utility line trenches, to verify proper compaction. • When/if any unusual geotechnical conditions are encountered. • Prior to interior and exterior 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 slabs. 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. I Collins Island, Newport Beach (Collins Island), CA Soils Report -Proposed Residence l'rOJCCI No. RS276 I Dec~mbcr 14. 2020 17 PA2021-055 Associated References re: Liquefaction Analysis a. "Special Publication 117 A: Guidelines for Evaluating and Mitigating Seismic Hazards in California," by the California Department of Conservation, California Geological Survey, dated March 13, 1997; Revised September 11, 2008. b. "Recommended Procedures for Implementation of DMG Special Publication 117 Guidelines for Analyzing and Mitigating Liquefaction Hazards in California," by G.R. Martin and M. Lew, University of Southern California Earthquake Center dated March, 1999. c. "Soil Liquefaction During Earthquakes" by I.M. Idriss and R.W. Boulanger, dated September 8, 2008. d. "Soils and Foundations, 8th Edition," by Cheng Liu and Jack B. Evett, dated August 4, 2013. e. "Evaluation of Settlement in Sands due to Earthquake Shaking" by Kahaji Tokimatsu and H. Bolton Seed, Dated August 1987. f. "Guidelines for Estimation of Shear Wave Velocity Profiles" By Bernard R. Wair, Jason T. Jong, Thomas Shantz Pacific Earthquake Engineering Research Center, Dated December, 2012. g. "Subsurface Exploration Using the Standard Penetration Test and the Cone Penetrometer Test," by J. David Rogers, Environmental & Engineering Geoscience, pp. 161-179, dated May, 2006. h. "Handbook of Geotechnical Investigation and Design Tables" By Burt G. Look, Dated 2007. I. "Use of SPT Blow Counts to Estimate Shear Strength Properties of Soils: Energy Balance Approach," by Hiroshan Hettiarachi and Timothy Brown, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, pp. 830-834, dated June, 2009. j. "Standard Test Method for Performing Electronic Friction Cone and Piezocone Penetration Testing of Soils," (ASTM D5778-12), dated 2012. k. "Evaluation of Settlements in Sand Deposits Following Liquefaction During Earthquakes," by Ishihara and Yoshimine, dated 1992. L "CPT and SPT Based Liquefaction Triggering Procedures" by R.W. Boulanger and I.M. Idriss, dated April 2014. 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. "Maximum Credible Rock Acceleration from Earthquakes in California," by Roger W. Reensfelder, dated 1974. 4. 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. 5. "Guide for Concrete Floor and Slab Construction," by American Concrete Institute, ACI 302.1 R- 04, dated 2004. 6. "California Building Code, California Code of Regulations, Title 24, Part 2," by California Building Standards Commission, 2019. 7. "Seismic Hazard Zone Report for the Newport Beach 7.5-Minute Quadrangles, Orange County, California," by the California Department of Conservation, 1997. 8. "2015 International Building Code," by the International Code Council, dated June 5, 2014. 9. "Geologic Map of California, Santa Ana Sheet," Compilation by Thomas H. Rogers, 1965, fifth printing 1985. 10. "Digital Elevation Model NAVD88 Mosaic," by NOAA National Centers for Environmental Information (NCEI), Created August 20, 2015, last modified September 23, 2016. I Collins Island, Newport Ueach (Collins Island), CA Soils Report -Proposed Residence PrOJCCl No. RS276. I l)~ccmbcr 14. 2020 18 PA2021-055 Loiver Neivpo1·~ Bay $' cs" ~ ~ ~~ port Bay Collins Isl LOCATION --....;;-===---- . . , ~ )... ~I " ~ ~ ~ N BAY FRONT _ Q:: ~ ~ BALBOA AVE Balboa Islancl PARK AVE V, S BAY FRONT _____ """"""' ..... Balboa Source: "US Topo 7.5-minute map for Newport Beach OE S, CA," by USGS, dated September 7, 2018. EGA SITE LOCATION MAP Project No: RS276.1 Consultants 1 COLLINS ISLAND engineeringgeotechnical applications NEWPORT BEACH, CALIFORNIA Date: DEC 2020 Figure No: 1 PA2021-055 EXISTING SEAWALL _______ _:B-1 1 COLLINS ISLAND PROPOSED RESIDENTIAL CPT-1 ~ FOOTPRINT ~8-2 2 COLLINS ISLAND LEGEND -$-GEOTECHNICAL BORINGS BY EGA CONSULTANTS 0 CONE PENETRATION TEST BY KEHOE TESTING AND ENGINEERING NEWPORT BAY 73' INSET MAP OF COLLINS ISLAND Reference: BALBOA ISLAND P.L. "Site Plan, Private Residence, 1 Collins Island, Newport Beach, CA 92662," by Sinclair Associates Architects, A.I.A., dated August 24, 2020. EGA Consultants engineering geotechnical applications PLOT PLAN 1 COLLINS ISLAND NEWPORT BEACH, CALIFORNIA Project No: Date: Figure No: RS276.l DEC 2020 2 PA2021-055 r:.>\:i·~--:_,,;·~1 Eolian deposits (late Holocene)-Active or recently active l,:·,.-:_,, .. -;· ·. sand dune deposits; unconsolidated. I Om 1 · des ·I Marine deposits {late Holocene)-Active or recently active . beach deposits; sand, unconsolidated. ·j Estuarine deposits {late Holocene)-Sand, silt, and clay; _ unconsolidated, contains variable amounts of organic matter. Oop4 ~--~I Old paralic deposits, Unit 4 (late to middle Pleistocene)- '-----'· Silt, sand and cobbles resting on 34-37 m Stuart Mesa terrace. Age about 200,000-300,000years. I Old paralic deposits, Unit 3 (late to middle Pleistocene)- '-----'· Silt, sand and cobbles resting on 45-46 m Guy Fleming Qop3 terrace. Age about 320,000-340,000 years. Qomf3 I Old 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 Qop1 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 paralic deposits capped by sandy alluvial-fan deposits. Capistrano Formation (early Pliocene and Miocene)- Marine sandstone. Siltstone facies-Siltstone and mudstone; white to pale gray, massive to crudely bedded, friable. Tm I 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. 1:100,000 scale. EGA Consultants engineering geotcchnical applications GEOLOGIC MAP 1 COLLINS ISLAND NEWPORT BEACH, CALIFORNIA Project No: RS276.1 Date: DEC 2020 Figure No: 3 PA2021-055 u s H A R B 0 R s II • -■ Balboa Pier, Newport Beach, CA -Nov 2020 High Low ' Date 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 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 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 52 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 • Sat 7:39 6.6 8:41 4.6 1:30 0.8 2:37 -0.9 6:23 4:51 Sun 8:1 6 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 1:48 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 0 -- 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 0 Fri 6:54 5.5 7:51 3.8 12:43 1.4 1:53 0.3 6:35 4:46 Sat 7:1 6 5.6 8:30 3.7 1:09 1.7 2:24 0.0 6:36 4:46 0 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 -0.3 6:38 4 :45 0 EGA TIDAL CHART Project No: RS276.1 Consultants 1 COLLINS ISLAND Date: DEC 2020 engineering geotechnical applications NEWPORT BEACH, CALIFORNIA Figure No: 4 PA2021-055 APPENDIX A GEOLOGIC LOGS (B-1 and B-2) and CPT Data Report by Keyhoe Drilling & Testing (CPT-1) PA2021-055 UNIFIED SOIL CLASSIFICATION SYSTEM ASTM D-2457 UNIFIED SOIL CLASSIFICATION AND SYMBOL CHART COARSE-GRAINED SOILS (more than 50% of material is larger than No. 200 sieve size.) GRAVELS More than 50% of coarse fraction larger than No. 4 sieve size Clean Gravels (Less than 5% fines) ... ... ; GW Well-graded gravels. gravel-sand ~l-mixtures, little or no fines GP Poorly-graded gravels. gravel-sand mixtures, little or no fines Gravels with fines (More than 12% fin.;;.esc..) __ _ GM GC Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Clean Sands (less than 5% fines) 7 SANDS 50% or more of coarse SW Well-graded sands, gravelly sands, ~ little or no fines SP Poorly graded sands, gravelly sands, little or no fines II raction sma er Sands with fines (More than 12% fines\ than No. 4 sieve size I I I, SM Silty sands, sand-silt mixtures SC Clayey sands, sand-clay mixtures FINE-GRAINED SOILS (50% or more of material is smaller than No. 200 sieve size.) SILTS ML AND CLAYS Liquid limit CL less than 50% OL SILTS MH AND CLAYS CH Liquid limit 50% or grealer ·:..:':~--~ ' .... OH ·"' 1t HIGHLY ORGANIC PT SOILS Cohesionless Sands and Silts Very loose Loose Medium dense Dense Very dense Inorganic silts and very fine sands. rock flour, silty of clayey fine sands or clayey silts with slight plasticity Inorganic clays of tow to medium plasticity. gravelly clays. sandy clays, silty clays, lean clays Organic silts and organic silty clays of IOw plasticity Inorganic silts. micaceous or diatomaceous fine sandy or silly soils, elastic silts Inorganic clays of high plasticity, fat days Organic clays of medium to high plasticity. organic silts Peat and other highly organic soils RELATIVE DENSITY Blows/ft* Blows/ft** 0-4 0-30 4-10 30-60 10-30 80-200 30-50 200-400 Over 50 Over400 I I I LABORATORY CLASSIFICATION CRITERIA 0 so D30 GW Cu = --greater than 4, Cc "' ---between 1 and 3 o,o 0,0 x 0 60 GP Not meeting all grada~on requirements for GW GM Atterberg limits below "A" Above "A" line with P.I. between line or P.1. less than 4 4 and 7 are border11ne cases GC Atterberg limits above "A" requiring use of dual symbols line with P. I. greater than 7 D50 D30 Cu = --greater than 4; Cc = ---between 1 and 3 SW D10 D10XD60 SP Not meeting all gradation requirements for GW SM Atterberg limits below "A" Limits plotting in shaded zone line or P.t. less than 4 with P.t. between 4 and 7 are Atterberg hmits above • A" borderline cases requiring use SC line with P.I. greater than 7 of dual symbols. Determine percentages of sand and gravel from grain-size curve. Depending on percentage of Fones (lract,on smaller than No. 200 sieve size), coarse-gra,neo sods are classified as follows: Less than 5 percent .................................... GW, GP, SW, SP More than 12 percent .................................. GM, GC, SM, SC 5 to 12 percent , ............ , ..... Borderline cases requmng dual symbols PLASTICITY CHART 60 l / ==-50 / !=.. CH / )( 40 1/i" A LINE: w 0 Pl = 0.73(LL-20) ~ 30 / I ~ CL MH&OH u 20 . j:: / 17 en j 10 L+# ,, ML&,OL Q, 00 10 20 30 40 50 60 70 80 90 100 LIQUID LIMIT (LL) (%) CONSISTENCY Cohesive Soils Blows/ft* Blows/ft** Very soft 0-4 0-4 Soft 2-4 4-11 Firm 4-8 11-50 Stiff 8-16 50-110 Very stiff 16-32 110-220 Hard Over 32 Over220 • Blows/foot for a 140-pound hammer falling 30 inches to drive a 2-inch 0.0., 1-3/8 inch 1.0. Split Spoon sampler (Standard Penetration Test). •• Blows/foot for a 36-pound hammer falling 24 inches to drive a 3.25 0.0., 2.411.0. Sampler (Hand Sampling). Blow count convergence to standard penetration test was done in accordance with Fig. 1.24 of Foundation Engineering Handbook by H.Y. Fang, Von Nostrand Reinhold, 1991. PA2021-055 - LOG OF EXP LORA TORY BORING Sheet 1 of 1 Job Number: RS276.1 Boring No: B-1 Project: 1 Collins Island, Newport B,each, CA Boring Location: See Figure 2 Proposed SFR Date Started: 11/17/2020 Rig: Mob. 4" augers Date Completed: 11/17/2020 Grnd Elev. +/-9 ft. NAVD88 Sample "$. 'tl Direct Type X Q. Shear Q> "E 'tl Q) -~ en ■ThinWall [8)2.S"Ring Q. "O f- Q) Q) ~ ~ .E: <fl en u. Q. "O Tube Sample C C '1ii w >, Q) 0 ·;;; C Q) f-.5 f--e 0 D 0 Q. .>< (.) C ·;;; -e-a:: s:. ·o :, s [Z] Bulk [D Standard Split ¥'. Static Water l!! Q) E (.) w a. iii 0 C Q) en 'o en Sample Spoon Sample Table :, (II :, :t i!' Q. E f-D C iii D X ·;. 0 ~ ·o w ~ (II ~()II ni=~r.RIPTl()N ~ I FILL: Light to dark brown, fine-grained silty sand 1 SP with organics, dry to moist, loose to medium dense, Opt% SM X more siltv with depth. 3.5 100.8 108.0 29.0 94 12.0% .__ SM At 2.5 ft.: Medium to dark brown, fine-grained silty Sulf 7 sand, micaceous with shells, moist to very moist. 11.8 17ppm 5 -SC At 4 ft.: Dark grayish brown, moist to very moist, \j / sandy clay, micaceous, firm. 22.6 SM -At 5.5 ft: fine-to medium-grained silty sand. ~ At 6.5 ft: Groundwater encountered. 21.6 SM At 8 ft.: Medium olive brown, fine silty sand, 10 -medium dense to dense saturated. .-\. ,-1 ; . .; ·. I I Total Depth: 10.0 ft. .-Groundwater at 6.5 feet. Caving at 8 feet. 15 -Backfilled and Compacted 11/17/2020. 20 - 25 - 30 - " . . -- 35 - 40 I EGA Consultants II ':."1ffi I PA2021-055 - LOG OF EXPLORATORY BORING Sheet 1 of 1 Job Number: RS276.1 Boring No: B-2 Project: 1 Collins Island, Newport Beach, CA Boring Location: See Figure 2 Proposed SFR Date Started: 11/17/2020 Rig: Mob. 4" augers Date Completed: 11/17/2020 Grnd Elev. +/-9 ft. NAVD88 Sample ~ 0 Direct Type 0 X a. Shear QI "E 0 (I) i-(/) ■ThinWall IX] 2.5" Ring a. "O f- (I) (I) (I) .i .£: 1/) (/) lL a. "O Tube Sample "E C 'ti w ~ (I) 0 C (I) f-.s € 1/) 0 0 0 a. (.) C 0:: ,::: :, X. [Zj Bulk OJ standard.Split sz static Water ~ ·;;; -e- ii ·5 ~ :i ~ C E (.) w (/) en Sample Spoon Sample = Table :, co :, I (I) "O -:;; 2:' a. E f- 0 C 0 X ·x 0 ::> ·o w ~ co c:n11 ncc:1"01PTl()N ~ I FILL: Light to dark brown, fine-grained silty sand 1 SP with organics, moist, loose to medium dense, Opl 'II. SM '5< trace shell fraqmnts, more silty with deoth. 12.2 95.5 108.0 29.0 94 12.0% .__ At 2.5 ft.: Medium to dark brown, fine-grained silty SM Sulf z sand, micaceous, with shells, moist to very moist. 17 ppm 5 -SC At 4 ft.: Dark grayish brown, moist to very moist. 20.1 I'\? / sandy clay, micaceous, firm. SM -At 5.5 ft: fine-to medium-grained silty sand. 25.8 z At 6 ft: Groundwater encountered. SM At 8 ft.: Medium olive brown, fine silty sand, 33.5 10-: medium dense to dense saturated. Total Depth: 10.0 ft. Groundwater at 6 feet. Caving at 8 feet (casing extended) 15 -Backfilled and Compacted 11/17/2020. ; . 20 -' ' ' 25 - 30 - 35 - 40 I EGA Consultants II ·:~~· I PA2021-055 K~ Project: EGA Consultants, LLC Kehoe Testing and Engineering 714-901-7270 rich@kehoetesting.com www.kehoetesting.com Location: s Colllns Island Newport Beach, CA Cone resistance qt Sleeve friction 0 0 2 2 4 6 6 8 8 10 10 12 12 14 16 16 18 18 20 20 ,....._ 22 ,....._ 22 ~ ~ .... ~ ._... 24 .s= .s= ~ 0.. 26 ~ 0.. 26 (I) (I) 0 28 0 28 30 30 32 32 3 3 36 36 38 38 40 42 42 44 46 46 48 48 so so 0 100 200 300 400 500 0 2 4 6 8 T ip resistance (tsf ) Friction (tsf) 0, Pore pressure u 2, 4. 6, 8, ::~ \ 14 16 18, 20, ~ "j \ ._... 24 .s= 0. 26 (I) 0 28 30- 32. 34 36 38 40 42 44 46 48 50 -5 0 5 10 15 Pressure (psi) CPeT-IT v.1.7.6.42. -CPTU data presentation & interpretation software -Report created on: 2/17/2016, 8:34:56 AM Project file: C:\EGANewport8each2-16\CPeT Data\Plot Data\Plots.q,t Friction ratio 12· 14 16, ,....._ 22, ,t:'. ....... 2• .s= ~ 0.. (I) 0 34. 36, 38, 40· 42, 44. 46, 48, so. 0 2 4 6 Rf(%) 0, 2- 4, 6- 8, 10- 12, 14 16, 18 20 ,....._ 22 ~ .._ ._... 24, .s= O. 26· (I) 0 28- 30, 32, 34. 36 38 40 42 44. 46- 48. 50, I 0 CPT: CPT-1 Total depth: 45.52. ft, Date: 2./15/2.016 Cone Type: Vertek Soil Behaviour Type Sand & silty sand Silty sand & sandy sil Silty sand & sandy sil Clay & silty clay Clay & sil~clay Silty sand & sandy sil Sand & silty sand Silty sand & sandysi Sand & silty sand Silty sand & sandysil Sand & silty sand Silty sand & sandysil Sand & silty sand Sand Sand & silty sand Very dense/stiff soil Very dense/stiff soil Very dense/stiff soil Very dense/stiff soil Sand & silty sand Silty sand & sandy sill . . . . . 4 6 8 10 12 14 16 18 SBT (Robertson, 2010) D PA2021-055 1 Collins Island, Newport Beach, CA EGA Consultants Project No: RS276. 1 December 2020 In situ data Est Depth qc (ts!) fs (tsf) SBTn Ksbt SPTN60 Constrained Dr (0/o) Friction Es (ts!) Go (ts!) Nkt (ft) (ft/s) (blows/ft) Mod, (ts!) angle (0 ) 96.9 0.83 6 7.SOE-04 18 590.47227 94 45 471.12149 S90.47227 0 2 77.1 0.72 6 2.78E-04 16 561.75345 78 43 448.20754 561.75345 0 70.4 0.62 6 l.85E-04 15 551.52649 69 42 440.04773 551.52649 0 4 21.4 0.51 s 2.56E-06 7 296.35138 42 37 287.80237 360.7123 0 11.2 0.09 5 2.52E-06 4 152.75705 28 33 148.77582 186.46569 0 6 10.3 0.1 s l.20E-06 4 139.21312 26 33 154.9387 194.18983 0 7 34.9 0.32 6 l.69E--05 9 417.57506 42 37 333. 17159 417.57506 0 8 89.7 0.64 6 l.69E-04 19 712.39502 62 41 568.40028 712.39502 0 9 105.8 0.85 6 l.70E--04 23 839.6219 65 41 669.91109 839.6219 0 10 72.8 0.62 6 5.94E--05 17 696.62678 53 40 555.81924 696.62678 0 II 122.1 1.56 6 7.28E--OS 28 1129.08862 67 42 900.86858 1129.0886 0 12 98.6 1.34 6 3.69E--05 25 1029.13693 59 40 821.11989 1029.1369 0 13 113.3 1.54 6 4.42E--05 28 1145.09546 61 41 913.63999 1145.0955 0 14 166.3 2.36 6 7.97E--05 38 1513.47167 72 42 1207.5572 1513.4717 0 IS 119 1.71 6 3.56E--05 30 1249.95057 60 41 997.30098 1249.9506 0 16 82.5 1.28 5 l.23E--OS 23 1045.68064 49 39 834.31966 1045.6806 0 17 117 1.71 6 2.7SE--05 30 128S.69859 57 40 1025.8233 1285.6986 0 18 59.2 0.85 s 5.32E-06 18 813.82656 40 37 692.20628 867.S6521 0 19 118.9 0.91 6 8.83E--05 27 1057.33691 55 40 843.61987 1057.3369 0 20 179.8 1.35 6 2.31E--04 38 1347.60606 67 42 1075.2176 1347.6061 0 21 197.6 I.II 6 4.81E--04 39 1297.42207 70 42 1035.1772 1297.4221 0 22 289.5 2.73 6 3.62E--04 58 200<1.76678 83 44 1599.5'18 2004.7668 0 23 342.9 5.32 6 l.43E-04 75 2809.78654 89 44 2241.851 2809.7865 0 24 293.1 5 6 7.92E--05 68 2670.63893 81 44 2130.8289 2670.6389 0 25 290.6 2.72 6 3.12E-04 59 2065.17502 80 43 1647.746 2065.175 0 26 287.8 3.03 6 2.20E-04 61 2178.40077 78 43 1738.0857 2178.4008 0 27 264.1 2.34 6 2.56E-04 55 1943.90902 74 43 1550.9912 19~3.909 0 28 242.8 2.13 6 2.03E-04 52 1861.53213 70 42 1485.265 1861.5321 0 29 237.9 1.98 6 2.06E-04 50 1819.41695 69 42 1451.6625 1819.417 0 30 254.3 0.95 6 1.17E--03 46 1421.23231 72 42 1133.962 M2l.2323 0 31 267.9 2.14 6 2.71E--04 55 1950.39266 72 42 1556.1644 1950.3927 0 32 289.2 2.2 6 3.46E-0<1 58 2015.06764 74 43 1607.7667 2015.0676 0 33 302 3.23 6 1.66E--04 65 2404.25268 74 43 1918.2867 2404.2527 0 34 303.7 5.19 6 5.05E--05 73 2997.18391 72 42 2391.3701 2997.1839 0 35 319.9 6.35 6 3.66E--05 80 3347.36419 72 42 2670.7693 3347.3642 0 36 300.4 5.69 6 3.43E--OS 75 3177.77518 69 42 2535.4589 3177.7752 0 37 301.2 6.74 5 2.14E--05 79 3469.63029 68 42 2768.322 3469.6303 0 38 284.1 6.3 5 l.84E-05 75 3362.36799 65 41 2682.7404 3362.368 0 39 373.8 7.79 6 3.66E--05 93 3911.49463 75 43 3120.8734 3911.4946 0 40 3568 7.7 6 2.89E--05 91 3893.72105 72 42 3106.6923 3893.7211 0 41 354.3 7.88 s 2.51E--05 91 3965.43259 70 42 3163.909 3965.4326 0 42 319.8 7.17 5 l.88E--OS 85 3767.0066 66 42 3005.5904 3767 .0066 0 43 282.7 6.61 5 l.22E--05 78 3595.54756 60 41 2868.788 3595.5476 0 44 286 6.64 5 l.22E--05 79 3641.41722 60 41 2905.3861 3641.4172 0 45 210.1 5.07 5 5.07E--06 63 2903.37026 49 39 2491.1145 3122.1969 0 CPT-1 advanced 10 45.42 n by Kehoe Testing and Engineering on February 15, 2016. PA2021-055 APPENDIX B LABORATORY RESULTS PA2021-055 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 1 Collins Island Newport Beach, California Dear Mr. Worthington: December 4, 2020 Project No. 114-652-10 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. I By: _J';,,:-.,,.,~(~..¢::::'.:====~~::=~ t} · iel J. Morikawa, P Director of Engineering Attachment: Laboratory Test Results 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com PA2021-055 EGA Consultants Laboratory Test Results 1 Collins Island Newport Beach, California LABORATORY TEST RESULTS December 4, 2020 Project No. 114-652-10 Page 2 of 3 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' 100.8 3.5 B-1 @4.0' • 11.8 B-1 @ 6.0' * 22.6 B-1 @8.0' * 21.6 B-2@ 2.5' 95.5 12.2 B-2@ 4.0' * 20.1 B-2@ 6.0' * 25.8 B-2@ 8.0' * 33.5 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-2@ 0-3' Poorly-graded sand with shells and SP organics -light grayish brown B-2@ 6' Clayey sand -dark grayish brown SC 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com PA2021-055 EGA Consultants Laboratory Test Results 1 Collins Island Newport Beach, California Maximum Dry Density and Optimum Moisture Content December 4, 2020 Project No. 114-652-10 Page 3 of 3 Maximum dry density and optimurn 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(%) 8-2@ 0-3' 108.0 12.0 Sulfate Content 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' 17 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. ' • If . N 350 Fischer Ave. Front • Costa Mesa, CA 92626 • P: 714 668 5600 • www.G3Soi1Works.com PA2021-055 4,000 3,750 3,500 3,250 3,000 2,750 u.. 2,500 Cl) Cl. Cl) 2,250 Cl) UJ a::: I-C/) a::: 4: LU I Cl) 2,000 1,750 1,500 1,250 1,000 750 500 250 0 0 DIRECT SHEAR TEST Undisturbed .,. , .. ···•1 .; ·. :.,· .. · ... ;,. ,;, ........... ~..... . . . . ...... . . . . . . . . . . . . . . . . •·· ....... ' .. . . . . . ;. .... .:- ...... -··········· ........ ····••.-• .. •,••·.·• i ··:·:· ·:-·:··:···::·'·: ... -•. : •. , .•••• " , ••• -. .. -....••• 1,1,, -•• -.• '· .. -· ·:-. ··:· . -. . . . .-. _ _,.'. - ..... <. ~-•••••• . ' ' -. . ...... . . . . . . . . . -~ •.-... . . . . . .. . ... . .... .. . .. . . . " . : .. : ... :..: .. : ... : .... ,.., .. :.:.: ... : ;.,.,., ....... , .. ; ;., ·-· ···•··: ' •:• ~. '.: . . .. ' .. ·:··-· :··: :· . . . . ' ........ , .... -. . .. , .. " . ' . -' . . . . .... . .. . . ..... -·--·-... . . ,. . ,. ... ... ... . . . . . . . ... . . ...... , ... ".. . . . ........... '. . ..•. . ' ' . . . . -. . . . . . . . . ... . ......... -. . ... ·-· ... . . . .. . . ... --· ~-. . ' . -~ •• '# •.• •' ••• , , ••. ,· ...... . , .... , ......... , .. , ' . '.,,; .. , .. · . . ~ ,: ' . . . . ..... ''I•••••.••,. . -;., .. ,,; /, •; ,. ·,.-.. -.-... .. '••·· ...... ••··v · :·· ... . . . . . . : : . : : : : ' : : ·;.... : .. : ; . . .. : . " . : . -· ·-· ·-•. -.. ~ . . ; . -.. ·, -: .. :--. . .. . . ... .. . . .......... •'• ~ . . . . .. ... ... . . . . . . . ... ... . . . . . . . . . . . - -. . ...... ··• . . . .. . . . ... . -.-~ -.. ' . . .... , ~- , • ~ • , , , •: , • I ~ • •'• , , , ' ~ ' i ~ • • . ' ~ ' . ' . 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 NORMAL STRESS, PSF 1 Collins Island, Newport Beach COHESION 94 psf. FRICTION ANGLE 29.0 degrees symbol boring depth {ft.) symbol boring depth {ft.) FIGURE S-1 DIRECT SHEAR TEST 8-2 2.5 • ---+---+---+---+---+----I PN: 114-652-10 REPORT DATE: 12/04/20 ~~:J F,~,1 ,~r A\•(• Front ( l}~ltl Wt,,-••u1 ( A C))h:',.. "'hon ( i ltl / f;G8 C,600 c\VV•,"/(~;')Sc ii\.:\ )lk,c ( ! FIG. S-1 PA2021-055 APPENDIX C GENERAL EARTHWORKS AND GRADING GUIDELINES PA2021-055 GENERAL EARTHWORK AND GRADING GUIDELINES I. GENERAL These guidelines present general procedures and requirements for grading and earthwork including preparation of areas to be filled, placement of fill, installation of subdrains, and excavations. The recommendations contained in the geotechnical report are a part of the earthwork and grading specifications and should supersede the provisions contained herein in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. II. EARTHWORK OBSERVATION AND TESTING Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fi lls for conformance with the recommendations of the geotechnical report and these specifications. The consultant is to provide adequate testing and observation so that he may determine that the work was accomplished as specified. It should be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that the consultant may schedule his personnel accordingly. The contractor is to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, and these specifications. If in the opinion of the consultant, unsatisfactory conditions are resulting in a quality of work less than required in these specifications, the consultant may reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to determine the degree of compaction should be performed in accordance with the American Society for Testing and Materials Test Method ASTM: D 1557. I Collins Island, Newport Beach (Collins Island}. CA Soils Keport -Proposed Residence Project No. RS276. I December 14, 2020 PA2021-055 111. PREPARATION OF AREAS TO BE FILLED 1. Clearing and Grubbing: All brush, vegetation, and debris should be removed and otherwise disposed of. 2. Processing: The existing ground which is evaluated to be satisfactory for support of fill should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction. 3. Overexcavation: Soft, dry, spongy, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be over excavated down to firm ground, approved by the consultant. 4. Moisture Conditioning: Over excavated and processed soils should be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content near optimum. 5. Recompaction: Over excavated and processed soils which have been properly mixed and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent. 6. Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground should be benched. The lowest bench should be a minimum of 15 feet wide, and at least 2 feet deep, expose firm material, and be approved by the consultant. Other benches should be excavated in firm material for a minimum width of 4 feet. Ground sloping flatter than 5: 1 should be benched or otherwise over excavated when considered necessary by the consultant. 7. Approval: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches should be approved by the consultant prior to fill placement. IV. FILL MATERIAL 1. General: Material to be placed as fill should be free of organic matter and other deleterious substances, and should be approved by the consultant. Soils of poor I Collins Island, Newport Beach (Collins Island), CA Soils Report • Proposed Residence Project No. RS276. I December 14, 2020 2 PA2021-055 V. gradation, expansion, or strength characteristics should be placed in areas designated by the consultant or mixed with other soils until suitable to serve as satisfactory fill material. 2. Oversize: Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 12 inches, should not be buried or placed in fill, unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade or within the range of future utilities or underground construction, unless specifically approved by the consultant. 3. Import: If importing of fill material is necessary for grading, the import material should be approved by the geotechnical consultant. FILL PLACEMENT AND COMPACTION 1. Fill Lifts: Approved fill material should be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and should be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. 2. Fill Moisture: Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification or blended with drier material. Moisture-conditioning and mixing of fill layers should continue until the fill material is at a uniform moisture content at or near optimum. 3. Compaction of Fill: After each layer has been evenly spread, moisture- conditioned, and mixed, it should be uniformly compacted to not less than 90 percent of maximum dry density. Compaction equipment should be adequately sized and either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree of compaction. 4. Fill Slopes: Compacting of slopes should be accomplished , in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at I Collins Island, Ncwpon 13each (Collins Island), CA Soils R~pon • Proposed Residence Project No. RS276. I IJecember 14, 2020 3 PA2021-055 frequent increments of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent. 5. Compaction Testing: Field tests to check the fill moisture and degree of compaction will be performed by the consultant. The location and frequency of tests should be at the'b:msultant's discretion. In general, the tests should be taken at an interval not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of embankment. VI. SUBDRAIN INSTALLATION VII. Subdrain systems, if required, should be installed in approved ground and should not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade, or material. EXCAVATION Excavations and cut slopes should be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas should be performed, and/or remedial grading of cut slopes performed. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be made and approved by the consultant prior to placement of materials for construction of the fill portion of the slope. I Collins Island, Newport 13each (Collins Island), CA Soils Report • Proposed Residence Project No. RS276. I December 14, 2020 4 PA2021-055 APPENDIX D USGS Design Maps Detailed Report '1 ·' PA2021-055 L\TC Hazards by Location Search Information Coordinates: Elevation: Timestamp: Hazard Type: Reference Document: Risk Category: Site Class: 33.60827008707921, -117 .90026628834323 8 ft 2020-11-23T22:44: 14.331Z Seismic ASCE7-16 II O-default Basic Parameters Name Value Description Ss 1.388 MCER ground motion (period=0.2s) S1 0.493 MCER ground motion (period=1.0s) Go gle SMs 1.666 Site-modified spectral acceleration value SM1 • null Site-modified spectral acceleration value Sos 1.11 Numeric seismic design value at 0.2s SA So1 • null Numeric seismic design value at 1.0s SA * See Section 11.4.8 ..... Additional Information Name Value Description soc * null Seismic design category Fa 1.2 Site amplification factor at 0.2s fy * null Site amplification factor at 1.0s CRs 0.906 Coefficient of risk (0.2s) CR1 0.92 Coefficient of risk (1.0s) PGA 0.608 MCEG peak ground acceleration FPGA 1.2 Site amplification factor at PGA PGAM 0.729 Site modified peak ground acceleration TL 8 Long-period transition period (s) 8 ft ' RMap data ©2020 PA2021-055 SsRT 1.388 SsUH 1.532 SsD 2.619 S1RT 0.493 S1UH 0.536 S1D 0.824 PGAd 1.057 * See Section 11.4.8 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. Users should confirm any output obtained from this tool with the local Authority Having Jurisdiction before proceeding with design. Disclaimer Hazard loads are provided by the U.S. Geological Survey Seismic Design Web Services. While the information presented on this website is believed to be correct, ATC and its sponsors and contributors assume no responsibility or liability for its accuracy. The material presented in the report should not be used or relied upon for any specific application without competent examination and verification of its accuracy, suitability and applicability by engineers or other licensed professionals. ATC does not intend that the use of this information replace the sound judgment of such competent professionals, having experience and knowledge in the field of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the results of the report provided by this website. Users of the information from this website assume all liability arising from such use. Use of the output of this website does not imply approval by the governing building code bodies responsible for building code approval and interpretation for the building site described by latitude/longitude location in the report. PA2021-055 APPENDIX E LIQUEFACTION ANALYSES/SETTLEMENT COMPUTATIONS PA2021-055 1011111 facameter£: Peak Ground Acceleration: 0.729 Earthquake Magnitude: 7.2 Water Table Depth (m): 2.1336 Average y above water table (kN/mA3): 16 Average y below water table (kN/mA3): 18 Borehole diameter (mm): 34.925 Requires correction for Sample Liners (YES/NO): Sample Depth Number (m] 0.30 2 0.61 3 0.91 4 1.22 5 1.52 6 1.83 7 2.13 8 2.44 9 2.74 10 3.05 11 3.35 12 3.66 13 3.96 14 4.27 15 4.57 16 4.88 17 5.18 18 5.49 19 5.7'l 20 6.10 21 6.40 22 6.71 23 7.01 24 7.32 consultants Measured (NJ Soil Type (USCS) 18 SP 16 SP 15 SP 7 CL/SC 4 CL 4 CL/SC 9 SP 19 SP 23 SM 17 SM 28 SM 25 SM/ML 28 SM 38 SM 30 SM 23 SM/ML 30 SM 18 SM/ML 27 SM 38 SM 39 SM 58 SM 75 SM 68 SM engineerinx peotechnical applications NO Flag "Clay" Fines Energy "Unsaturated" Content Ratio "Unreliable" (%) (ER)% 4 65 4 65 4 65 Clay so 65 Clay so 65 Clay 50 65 4 65 4 65 13 65 13 65 13 65 so 65 13 65 13 65 13 65 so 65 13 65 50 65 13 65 13 65 13 65 13 65 13 65 13 65 CE CB CR cs 1.08 l 0.75 1 1.08 1 0.75 1 1.08 1 0.75 1 1.08 1 0.75 J J.08 1 0.8 l 1.08 1 0.8 1 1.08 1 0.8 l 1.08 1 0.8 1 1.08 1 0.85 1 1.08 1 0.85 I 1.08 1 0.85 1 1.08 1 0.85 1 1.08 1 0.85 1 1.08 1 0.85 1 1.08 1 0.95 1 1.08 1 0.95 I 1.08 J 0.95 l 1.08 1 0.95 1 1.08 1 0.95 1 1.08 1 0.95 I 1.08 1 0.95 1 1.08 1 0.95 1 1.08 I 0.95 1 1.08 1 0.95 1 N60 14.63 13.00 12.19 5.69 3.47 3.47 7.80 16.47 21.18 15.65 25.78 23.02 25.78 34.99 30.88 23.67 30.88 18.53 27.79 39.11 40.14 59.69 77.19 69.98 e1VC 4.88 9.75 14.63 19.51 24.38 29.26 34.14 39.62 45.11 50.60 56.08 61.57 67.06 72.54 78.03 83.52 89.00 94.49 99.97 105.46 110.95 116.43 121.92 127.41 1 Collins Island, Newport Beach, CA RS276.1 December 2020 e1VC' CN 4.88 1.70 9.75 1.70 14.63 1.70 19.51 1.70 24.38 1.70 29.26 1.70 34.14 1.70 36.63 1.66 39.13 1.61 41.63 1.56 44.12 1.52 46.62 1.47 49.12 1.44 51.61 1.40 54.11 1.37 56.60 1.34 59.10 1.31 61.60 1.28 64.09 1.26 66.59 1.23 69.09 1.21 71.58 1.19 74.08 1.17 76.57 1.15 PLATE A CPT-1 performed to 45.42 ft. on 2/15/2016 Page 1 PA2021-055 25 7.62 59 SM 13 65 1.08 1 0.95 1 60.72 26 7.92 61 SM 13 65 1.08 1 0.95 I 62.78 27 8.23 55 SM 13 65 1.08 1 0.95 1 56.60 28 8.53 52 SM 13 65 1.08 1 l l 56.33 29 8.84 50 SM 13 65 1.08 1 1 1 54.17 30 9.14 46 SM 13 65 I.OB 1 1 1 49.83 31 9.45 55 SM 13 65 1.08 1 1 1 59.58 32 9.75 58 SM 13 65 1.08 1 1 1 62.83 33 10.06 65 SM 13 65 1.08 1 1 I 70.42 34 10.36 73 SM 13 65 1.08 1 1 1 79.08 35 10.67 80 SM 13 65 1.08 1 1 1 86.67 36 10.97 75 SM 13 65 1.08 1 l 1 81.25 37 11.28 79 SM 13 65 1.08 1 1 1 85.58 38 11.58 75 SM 13 65 1.08 1 1 1 81.25 39 11.89 93 SM 13 65 1.08 1 1 1 100.75 40 12.19 91 SM 13 65 1.08 1 1 1 98.58 41 12.50 91 SM 13 65 1.08 1 1 l 98.58 42 12.80 85 SM 13 65 1.08 1 1 1 92.08 43 13.11 78 SM 13 65 1.08 1 1 1 84.50 44 13.41 79 SM 13 65 1.08 l 1 1 85.58 45 13.72 63 SM/ML so 65 1.08 I l I 68.25 Auger Diameter: 1.375 inches !lammer Weight: n.a. Drop: continuous push CPT-1 advanced to 45.42 ft by Kehoe Testing and Engineering on February 15. 2016 (CPT Data Logs attached herein) References Idriss, I. M. and Boulanger, R. W. S01/ Liquefaction Dunrig Earthquakes. Earthquake Eng,ne,nng Research Institute. 8 September 2008. Liu, C. and Eveu, J.B. Soils and Fovndalions. 8th E:.'dltion. 4 August 2013. Mar1111, G.R. and Lew. M. Rocommcndooonsfor lmplcmcntatton of DMG Spccral Pub/1cat1on I 17. Umvemty of Southem California Ear1hquake Center. March 1999. California Department of Conservation. CGS. Spec/al Pub/lcat/011 117A. Guidelines for Eva/uor,rig and Mltrgotlng Sel,-m/c 1/ozords in California. Rev 11 S•pt. 2008. consultants engineerinx xeotech11ical applications l Collins Island, Newport Beach, CA RS276.1 December 2020 132.89 79.07 1.13 138.38 81.57 1.11 143.87 84.06 1.10 149.35 86.56 1.08 154.84 89.06 1.o7 160.32 91.55 1.05 165.81 94.05 1.04 171.30 96.55 1.02 176.78 99.04 1.01 182.27 101.54 1.00 187.76 104.03 0.99 193.24 106.53 0.98 198.73 109.03 0.96 204.22 111.52 0.95 209.70 114.02 0.94 215.19 116.52 0.93 220.68 119.01 0.92 226.16 121.51 0.91 231.65 124.00 0.90 237.13 126.50 0.89 242.62 129.00 0.89 PLATE A CPT-1 performed to 45.42 ft. on 2/15/2016 Page 2 PA2021-055 (N1)60 t.N for Fines Content 24.86 0.00 22.10 0.00 20.72 0.00 n.a. n.a. n.a. n.a. n.a. n.a. 13.26 0.00 27.39 0.00 34.08 2.51 24.42 2.51 39.07 2.51 33.94 5.61 37.03 2.51 49.03 2.51 42.25 2.51 31.67 5.61 40.43 2.51 23.76 5.61 34.94 2.51 48.24 2.51 48.61 2.51 71.02 2.51 90.27 2.51 80.50 2.51 consultants (Nl)60-CS Stress reduction coeff, rd 24.86 1.00 22.10 1.00 20.72 1.00 n.a. 1.00 n.a. 0.99 n.a. 0.99 13.26 0.99 27.39 0.98 36.59 0.98 26.93 0.98 41.58 0.97 39.55 0.97 39.54 0,97 51.54 0.96 44.76 0.96 37.28 0.95 42.93 0.95 29.37 0.95 37.45 0.94 50.75 0.94 51.12 0.93 73.53 0.93 92.78 0.92 83.01 0.92 engineering xeotechnica/ applicatio11s CSR MSF for sand Q.48 1.08 0.47 1.08 0.47 1.08 0.47 1.08 0.47 1.08 0.47 1.08 0.47 1.08 0.50 1.08 0.54 1.08 0.56 1.08 O.S9 1.08 0.61 1.08 0.62 1.08 0.64 1.08 0.65 1.08 0.67 1.08 0.68 1.08 0.69 1.08 0.70 1.08 0.70 1.08 0.71 1.08 0.72 1.08 0.72 1.08 0.72 1.08 Ko for sand CRR for M"7.5 CRR &oVC'" 1 atm 1.10 0.29 0.34 1.10 0.23 0.28 1.10 0.21 0.26 1.10 n.a. n.a. 1.10 n.a. n.a. 1.10 n.a. n.a. 1.10 0.14 0.17 1.10 0.36 0.43 1.10 1.58 1.88 1.10 0.34 0.41 1.10 2.00 2.00 1.10 2.00 2.00 1.10 2.00 2.00 1.10 2.00 2.00 1.10 2.00 2.00 1.10 1.88 2.00 1.10 2.00 2.00 1.10 0.45 0.53 1.10 1.96 2.00 1.10 2.00 2.00 1.10 2.00 2.00 1.10 2.00 2.00 1.09 2.00 2.00 1.08 2.00 2.00 Factor of Safety 0.72 0.59 0.54 n.a. n.a. n.a. 0.36 0.85 2.00 0.73 2.00 2.00 2.00 2.00 2.00 2.00 2.00 0.78 2.00 2.00 2.00 2.00 2.00 2.00 1 Collins Island, Newport Beach, CA RS276.l December 2020 Limiting shear strain ylim 0.09 0.13 0.15 0.00 0.00 0.00 0.33 O.o7 0.02 0.o7 0.01 0.01 0.01 0.00 0.00 0.01 0.00 0.05 0.01 0.00 0.00 0.00 0.00 0.00 PLATE A CPT-1 performed to 45.42 ft. on 2/15/2016 Page 3 PA2021-055 68.74 2.51 71.24 0.91 0.73 1.08 1.07 69.97 2.51 72.48 0.91 0.73 1.08 1.06 62.14 2.51 64.65 0.90 0.73 1.08 1.05 60.95 2.51 63.46 0.90 0.74 1.08 1.05 57.78 2.51 60.28 0.89 0.74 1.08 1.04 52.43 2.51 54.93 0.89 0.74 1.08 1.03 61.85 2.51 64.35 0.88 0.74 1.08 1.02 64.37 2.51 66.88 0.88 0.74 1.08 1.01 71.22 2.51 73.73 0.87 0.74 1.08 1.01 79.00 2.51 81.51 0.87 0.74 1.08 1.00 85.53 2.51 88.04 0.86 0.74 1.08 0.99 79.24 2.51 81.75 0.86 0.74 1.08 0.98 82.51 2.51 85.01 0.85 0.74 1.08 0.98 77.45 2.51 79.95 0.85 0.74 1.08 0.97 94.98 2.51 97.48 0.84 0.74 1.08 0.96 91.93 2.51 94.44 0.84 0.73 1.08 0.96 90.96 2.51 93.47 0.83 0.73 1.08 0.95 84.09 2.51 86.60 0.83 0.73 1.08 0.95 76.38 2.51 78.89 0.82 0.73 1.08 0.94 76.59 2.51 79.10 0.82 0.73 1.08 0.93 60.49 5.61 66.10 0.81 0.72 1.08 0.93 References· Idriss, I.M. •nd Boulanger, R.W. Soil l1qutfottion Durmg Earthquakes. Ea11hquak• Engineenng Researdl Institute. 8 September 2008 Liu. C. .ind £\'en, J.B. Soi/sand Foundations. 8th Edition. 4 August 2013. 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 Martm. G.R. and Lew. M. Recomme11dat10ns for lmp/~mcntar1on of DMC Spec,al Publtconon 117. University of Sou them Cahfornia Earthquake Center. March 1999, (allfoml• Department ol Conservation, CGS. Spe<lol Pub/icotJon I/ 7A. Guidelines for £1'oluotirig and /.1/ugat1119 Se,sm/c 1/ozords in Calffornio Rev 11 Sept. 2008. consultants <-nRineering Kl'OTechnical applications 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00 1 Collins Island, Newport Beach, CA RS276.1 December 2020 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 o.oo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PLATE A CPT-1 performed to 45.42 ~-on 2/15/2016 Page 4 PA2021-055 Parameter Fa 0.24 0.40 0.48 0.00 0.00 0.00 0.82 0.08 ·0.55 0.11 -0.92 -0.77 -0.77 -1.71 -1.17 -0.60 -1.03 -0.05 -0.61 -1.65 -1.68 -3.61 -5.38 -4.47 Maximum LIHi (m) shear strain ymax 0.07 0.13 0.15 0.00 0.00 0.00 0.33 0.05 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 engineering georechnica/ applications 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 consultants LILDli (m) 0.02 0.04 0.04 0.00 0.00 0.00 0.10 0.01 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 Vertical LISi (m) reconsol. Strain i:v 0.02 0,01 0.02 0.01 0.02 0.Ql 0.00 0.00 0.00 0.00 0.00 0.00 0.◊3 0.Ql 0.01 0.00 0.00 0.00 O.Dl 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 o.oo 0.00 0.0, 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 LISi (ft) 0.02 0.02 0.02 0.00 0.00 0.00 0.03 0.Dl 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 O.Dl 0.00 0.00 0.00 0.00 0.00 0.00 LISi (inches) 0.20 0.25 0.27 0.00 0.00 0.00 0.38 0.13 0.00 0.17 I = 0.00 n=IO 1.40 1 Collins Island, Newport Beach, CA RS276.1 December 2020 0.00 Post Soil Cement Treatment: 0.00 o.oo I = 0.67 0.00 n=IO 0.00 o.oo 0.12 0.00 0.00 0.00 0.00 0.00 0.00 PLATE A CPT-1 performed to 45.42 ft. on 2/15/2016 Page 5 PA2021-055 -3.41 0.00 0.30 0.00 0.00 O.O!J -3.52 0.00 0.30 0.00 0.00 O.()(l -2.82 0.00 0.30 0.00 0.00 0.00 -2.72 0.00 0.30 0.00 0.00 O.Ol'l -2.45 0.00 0.30 0.00 0.00 0.00 -2.00 0.00 0.30 0.00 0.00 0,0,'J -2.80 0.00 0.30 0,00 0.00 0.00 -3.02 0.00 0.30 0,00 0.00 0.00 -3,63 0.00 0.30 0.00 0.00 O.CJO ·4,33 0.00 0.30 0.00 0.00 0.0lJ -4.94 0.00 0.30 0.00 0.00 0.00 -4.36 0.00 0.30 0.00 0.00 0.00 -4.66 0.00 0.30 0.00 0,00 0.00 ·4.19 0.00 0.30 0.00 0.00 0.00 -5.83 0.00 0,30 0.00 0.00 o.on -5.54 0.00 0.30 0.00 0.00 0.00 -5.45 0.00 0.30 0.00 0.00 0.00 •4.80 0.00 0.30 0.00 0.00 0.00 -4.10 0.00 0.30 0.00 0.00 0.00 ·4. I I 0.00 0.30 0.00 0.00 0.00 -2,95 0.00 0.30 0.00 0.00 0.00 Total Settlement: I 0.04{ References: ldnss. l.M. and Boulanger, R.W. Soil liquefaction Duri".9 Earthquakes. Earthquake Engineering Research lnsrltute. 8 SW'"'"'°""' ..:ioa Uu. C. and Evett, J.8. Soils and Foundations. 8th Edition. 4 Augusr 2013. !MlO 0.1'.l() 0.00 O.ClO {t.00 (1.00 o;oo (LO{) 0.00 O.t~O G.Ofl 0.0(l 0.00 (l,IJ(l 0.00 Q.00 0.00 0,0,'.) O::oo 0.{l(J o;i,f.l. 0.60 u.O,O 0.(,-0 o:oo c.-00 (iJ}() O.OG 0.()-0 0,00 0 .. ()0 0.00 -0.l\O OJJ(l ~-00 (1 .. ()4 (l.00 0.GO O.OiJ o.oo 0,00 0.00 ri.nJ ~----_, 1:521 Martin. G.R. and Lew. M. Recommendations /or lmplemenlDt1011 o{DMG Special Publicacion 117. Un1vers1ty of Southern ~?if.;;;rn~ l!.1rrlt~iai>:~C:t-~t..~. 53atY..h ;·919, C.llforn,a Department o( Conservarion. CCS. Special Publ/rotfon 117A. Gu1dtli11es for Evolua//ng and Mit19oting Se,sm/c f/a)Wr,i,s•t, IAlif,~. ~ L 1 ~pl: ZllM, consultants engineerinfl, ~eo1echnical applications l Col!lmi !s~nd, Newport Bec.1;::h, 0\ ~✓-75,1 D~r.ember 2020 ?LATf A CPT· 1 performed to 45.4'. ft. ~fl 2/lS/i0Hl ?a~6 PA2021-055