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HomeMy WebLinkAbout20210128_GEI Report_8-13-2020COAST GEOTECHNICAL, INC. Geotechnical Engineering Investigation of Proposed New Residence at 508 Via Lido Nord Newport Beach, California BY: COAST GEOTECHNICAL, INC. W. 0. 600320-01, dated August 13, 2020 FOR: Mr. and Mrs. John Devir 508 Via Lido Nord Newport Beach, CA 92663 PA2021-012 COAST GEOTECHNICAL, INC. 1200 W. Commonwealth Avenue, Fullerton, CA 92833 • Ph: (714) 870-1211 • Fax: (714) 870-1222 • E-mail: coastgeotec@sbcglobal.net August 13, 2020 Mr. and Mrs. John Devir 508 Via Lido Nord Newport Beach, CA 92663 Dear Mr. and Mrs. Devir: Subject: w.o. 600320-01 Geotechnical Engineering Investigation of Proposed New Residence at 508 Via Lido Nord, Newport Beach, California Pursuant to your request, a geotechnical engineering investigation has been performed at the subject site. The purposes of the investigation were to determine the general engineering characteristics of the near surface soils on and underlying the site and to provide recommendations for the design of foundations and underground improvements. The conclusions and recommendations contained in this report are based upon the understanding of the proposed development and the analyses of the data obtained from our field and laboratory testing programs. This report completes our scope of geotechnical engineering services authorized by you in the July 2, 2020 proposal. SITE DEVELOPMENT It is our understanding that the existing residence will be demolished and that the site is to be redeveloped with a new two-story residential structure over slab-on-grade. Structural loads are anticipated to be light. Significant grade changes are not anticipated. PURPOSE AND SCOPE OF SERVICES The scope of the study was to obtain subsurface information within the project site area and to provide recommendations pertaining to the proposed development and included the following: 1. A cursory reconnaissance of the site and surrounding areas. 2. Excavation of two exploratory borings to determine the near subsurface soil conditions and groundwater conditions. 3. Collection of representative bulk and/ or undisturbed soil samples for laboratory analysis. 4. Laboratory analyses of soil samples including determination of in-situ and maximum density, in-situ and optimum moisture content, shear strength characteristics, consolidation, expansion potential, and sulfate content. 5. Preparation of this report presenting results of our investigation and recommendations of the proposed development. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 2 Geotechnical Engineering Investigation SITE CONDITIONS w. 0. 600320-01 August 13, 2020 The project site is located at 508 Via Lido Nord in the City of Newport Beach, California, and is shown on the attached Site Vicinity Map, Plate 1. The parcel is rectangular in shape and is bordered by residential properties to the east and west, Lido Channel to the north, and Via Lido Nord to the south. The lot is currently developed with a single-family residence, hardscape, and landscape. Site configuration is further shown on the Site Plan, Plate 2. RECORD REVIEW Records were researched at the City of Newport Beach under the project address. The subject lot is identified as Lot 495 of Tract 907. Geotechnical records were found for the subject lot. • Preliminary Soils and Engineering and Foundation Investigation, Proposed Single-Family Residence at 508 Via Lido Nord, Newport Beach, California.-.. , by Petra Geotechnical Inc. J.N. 245-89 dated June 8, 1989. • Final Soils Engineering Report of Rough Grading, 508 Via Lido Nord, Newport Beach, California ... , by Petra Geotechnical Inc. J.N. 245-89 dated November 2, 1989. • Final Soils Report,Iinterior and Exterior Utility Trench Bac/ifi,// and slab subgrade, 508 Via Lido Nord, Newport Beach, California ... , by Petra Geotechnical Inc. J.N. 245-89 dated April 17, 1990. Earthwork was observed and tested between 1989 and 1990 during grading and construction for the residence by Petra Geotechnical Inc. Readers of this report are advised that a record search is not an exact science; it is limited by time and resource constraints, incomplete records, ability of custodian of records to locate files, and where records are located is only a limited interpretation of other consultant's work. Readers of this report should perform their own review of City records to arrive at their own interpretations and conclusions. EXPLORATORY PROGRAM The field investigation was performed on July 29, 2020, consisting of the excavations of a boring by a limited access drilling equipment (for Boring No. 1) and a boring by hand auger equipment (for Boring No. 2) at the locations shown on the attached Site Plan, Plate 2. As excavations progressed, a representative from this office visually classified the earth materials encountered, and secured representative samples for laboratory testing. Geotechnical characteristics of subsurface conditions were assessed by either driving a split spoon ring sampler or an SPT sampler into the earth material. Undisturbed samples for detailed testing in our laboratory were obtained from Boring No. 2 by pushing or driving a sampling spoon into the earth material. A solid-barrel type spoon was used having an inside diameter of 2.5 inches with a tapered cutting tip at the lower end and a ball valve at the upper end. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 3 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 The barrel is lined with thin brass rings, each one inch in length. The spoon penetrated into the earth materials below the depth of borings approximately six inches. The central portion of this sample was retained for testing. All samples in their natural field condition were sealed in airtight containers and transported to the laboratory. Standard Penetration Test (SPT) was performed for Boring No. 1, based on ASTM D1586. The number of blows required for driving the sampler through three six-inch intervals is recorded. The sum of the number of blows required for driving the last two six-inch intervals is referred to as the standard penetration number "N". Samplers from Boring No. 1 were driven into the soil at the bottom of the borehole by means of hammer blows. The hammer blows are given at the top of the drilling rod. The blows are by a hammer weighing 140 pounds dropped a distance of 30 inches. Drive sampling was obtained at two feet intervals for the upper level foundations in accordance with City guidelines. Considering that the upper three feet of the pad area will be recompacted, SPT sampling commenced at three feet below grade. For liquefaction analysis, CE of 1.0 (for safety hammer), CB of 1.05 (for seven inch borehole diameter), and Cs of 1.2 (for sampler without liners) are used to calculate corrected N values. EARTH MATERIALS Earth materials encountered within the exploratory borings were visually logged by a representative of COAST GEOTECHNICAL, Inc. The earth materials encountered were classified as artificial fill underlain by native soils to the maximum depth explored. Artificial fills encountered consisted of brown to tan brown silty fine to medium grained sand and sandy silt, dry to damp and generally loose to medium dense. The fills were encountered to a depth of about two feet below existing grade. Native soils encountered consisted of tan and light gray tan, clean, fine to medium grained sand, damp to moist and light gray tan to gray slightly silty, fine to medium grained sand, moist to wet, and generally medium dense, to maximum depth explored of 12.5 feet. Logs of the exploratory borings are presented on the appended Plates B and C. GROUNDWATER Groundwater was encountered at 8.5 to 9.0 feet below existing ground surface during the field investigation. This groundwater level is subject to minor fluctuation due to tidal changes. Plate 1.2 in Appendix B shows the subject site area to have a historic high groundwater depth ofless than ten feet below existing ground surface. In our liquefaction and seismic settlement analyses, a groundwater elevation of six feet below ground surface is used for more conservative calculations in accordance with City policy. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 4 Geotechnical Engineering Investigation SEISMICITY w. 0. 600320-01 August 13, 2020 Southern California is located in an active seismic region. Moderate to strong earthquakes can occur on numerous faults. The United States Geological Survey, California Division of Mines and Geology, private consultants, and universities have been studying earthquakes in Southern California for several decades. Early studies were directed toward earthquake prediction estimation of the effects of strong ground shaking. Studies indicate that earthquake prediction is not practical and not sufficiently accurate to benefit the general public. Governmental agencies are shifting their focus to earthquake resistant structures as opposed to prediction. The purpose of the code seismic design parameters is to prevent collapse during strong ground shaking. Cosmetic damage should be expected. Within the past 49 years, Southern California and vicinity have experienced an increase in seismic activity beginning with the San Fernando earthquake in 1971. In 1987, a moderate earthquake struck the Whittier area and was located on a previously unknown fault. Ground shaking from this event caused substantial damage to the City of Whittier, and surrounding cities. The January 17, 1994, Northridge earthquake was initiated along a previously unrecognized fault below the San Fernando Valley. The energy released by the earthquake propagated to the southeast, northwest, and northeast in the form of shear and compression waves, which caused the strong ground shaking in portions of the San Fernando Valley, Santa Monica Mountains, Simi Valley, City of Santa Clarita, and City of Santa Monica. Southern California faults are classified as: active, potentially active, or inactive. Faults from past geologic periods of mountain building, but do not display any evidence of recent offset, are considered "inactive" or ''potentially active". Faults that have historically produced earthquakes or show evidence of movement within the past 11,000 years are known as "active faults". There are no known active faults within the subject property, with the nearest being the Newport Inglewood Fault Zone and the San Joaquin Blind Thrust Fault. • Newport-Inglewood Fault Zone: The Newport-Inglewood Fault Zone is a broad zone of left-stepping en echelon faults and folds striking southeastward from near Santa Monica across the Los Angeles basin to Newport Beach. Altogether these various faults constitute a system more than 150 miles long that extends into Baja California, Mexico. Faults having similar trends and projections occur offshore from San Clemente and San Diego (the Rose Canyon and La Nacion Faults). A near-shore portion of the Newport-Inglewood Fault Zone was the source of the destructive 1933 Long Beach earthquake. The reported recurrence interval for a large event along this fault zone is 1,200 to 1,300 years with an expected slip of one meter. • San Joaquin Hills Blind Thrust Fault: The seismic hazards in Southern California have been further complicated with the recent realization that major earthquakes can occur on large thrust faults that are concealed at depths between 5 to 20 km, referred to as "blind thrusts." The uplift of the San Joaquin Hills is produced by a southwest dipping blind thrust fault that extends at least 14 km from northwestern Huntington Mesa to Dana Point and comes to within 2 km of the ground surface. Work by Grant et al. (1997 and 1999) suggest that uplift of the San Joaquin Hills began in the Late Quaternary and continues during the Holocene. Uplift rates have been estimated between 0.25 and 0.5 mm/yr. If the entire length of the fault ruptured, the earthquake has been estimated to generate an Mw 6.8 event. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 5 Geotechnical Engineering Investigation w. 0. 600320-01 . August 13, 2020 We are of the opinion that the more active Newport Inglewood fault is the causative fault for the subject site. The site is located approximately 1.5 kilometers northeast, of the Newport Inglewood fault. SEISMIC HAZARDS The potential hazards to be evaluated with regard to seismic conditions include fault rupture, landslides triggered by ground shaking, soil liquefaction, earthquake-induced vertical and lateral displacements, earthquake-induced flooding due to the failure of water containment structures, seiches, and tsunamis. Fault Rupture The project is not located within a currently designated Alquist-Priolo Earthquake Zone (Bryant and Hart, 2007). No known active faults are mapped on the site. Based on this consideration, the potential for surface fault rupture at the site is considered to be remote. Ground Shaking The site is located in a seismically active area that has historically been affected by moderate to occasionally high levels of ground motion, and the site lies in relatively close proximity to several active faults; therefore, during the life of the proposed development, the property will probably experience moderate to occasionally high ground shaking from these fault zones, as well as some background shaking from other seismically active areas of the Southern California region. Residential structures are typically designed to maintain structural integrity not to prevent damage. Earthquake insurance is available where the damage risk is not acceptable to the client. Seismic Induced Landslide Earthquake-induced landslide zones were delineated by the State of California using criteria adopted by the California State Mining and Geology Board. Under those criteria, earthquake- induced landslide zones are areas meeting one or more of the following: 1. Areas known to have experienced earthquake-induced slope failure during historic earthquakes. 2. Areas identified as having past landslide movement, including both landslide deposits and source areas. 3. Areas where CDMG's analyses of geologic and geotechnical data indicate that the geologic materials are susceptible to earthquake-induced slope failure. Based on the Seismic Hazard Zone Map published by the State of California, Newport Beach Quadrangle, appended as Plate 3, the site is not mapped as being in an area subject to potential seismic induced landslides. Seismic Induced Liquefaction Liquefaction is a seismic phenomenon in which loose, saturated, non-cohesive granular soils exhibit severe reduction in strength and stability when subjected to high-intensity ground PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir Geotechnical Engineering Investigation 6 w. 0. 600320-01 August 13, 2020 shaking. The mechanism by which liquefaction occurs is the progressive increase in excess pore pressure generated by the shaking associated with the seismic event and the tendency for loose non-cohesive soils to consolidate. As the excess pore fluid pressure approaches the in-situ overburden pressure, the soils exhibit behavior similar to a dense fluid with a corresponding significant decrease in shear strength and increase in compressibility. Liquefaction occurs when three general conditions exist: 1) shallow groundwater; 2) low density, non-cohesive sandy soils; and 3) high-intensity ground motion. Seismic Hazard Zone Maps published by the State of California have been prepared to indicate areas that have a potential for seismic induced liquefaction hazards. The Seismic Hazard Zone Map for the Newport Beach Quadrangle, appended as Plate 3, shows the site to be mapped as being subject to potential liquefaction hazards. The City of Newport Beach has a policy concerning these areas. The City has assigned certain parameters to existing soil conditions. From ten to thirty feet below ground surface they have assigned the zone to be liquefiable with a seismic settlement of three inches. From thirty to fifty feet below ground surface they have assigned liquefaction and seismic settlement not to be of concern. The client has the option of accepting these conditions and assessing the zone of earth materials from the ground surface to ten feet below the proposed footing bottom for liquefaction and seismic settlement, or ignoring the City conditions and drilling deep exploration for similar assessment. For this project shallow exploration was chosen. A liquefaction assessment for the upper earth materials follows. Liquefaction evaluation for soil zone to ten feet below foundation bottom was based on blow counts from Boring No. 1, a M = 7.2 seismic event from the Newport-Inglewood fault, a maximum ground acceleration of 0. 727 g PGAM and a groundwater level at six feet. Liquefaction analysis, based on these values and field obtained data, is presented in Appendix B. The results indicate that there is liquefaction potential for the subject site. Lateral Spreading The occurrence of liquefaction may cause lateral spreading. Lateral spreading is a phenomenon in which lateral displacement can occur on the ground surface due to movement of non-liquefied soils along zones of liquefied soils. For lateral spreading to occur, the liquefiable zone must be continuous, unconstrained laterally, and free to move along sloping ground toward an unconfined area. Due to the relatively level lot and distance to a free face, the potential of lateral spreading is not considered to be significant. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 7 Geotechnical Engineering Investigation Earthquake-induced Settlements w. 0. 600320-01 August 13, 2020 Earthquake-induced settlements result from densification of non-cohesive granular soils which occur as a result of reduction in volume during or after an earthquake event. The magnitude of settlement that results from the occurrence of liquefaction is typically greater than the settlement that results solely from densification during strong ground shaking in the absence ofliquefaction. It is understanding that the current City policy, has assigned a seismic settlement potential of three inches for soils depths of ten to thirty feet and no additional analysis of seismic settlement for this level should be required. The seismically induced settlement for the at-grade structure was evaluated based on the "Evaluation of Settlement in Sands due to Earthquake Shaking" by Kahji Tokimatsu and H. Bolton Seed, dated August 1987. The analysis was limited to ten feet below the footing bottom. The result, based on the SPT N-values in Boring No. 1, groundwater table at six feet below grade and shown in Appendix C, indicates that the estimated settlement (including dry and saturated sands) is 0.30 inch. According to City policy, the City's shallow mitigation method may be used since the seismic settlement is less than one inch to a depth of ten feet below proposed foundations. Earthquake-Induced Flooding The failure of dams or other water-retaining structures as a result of earthquakes and strong ground shaking could result in the inundation of adjacent areas. Due to the lack of a major dam or water-retaining structure located near the site, the potential of earthquake-induced flooding affecting the site is considered not to be present. Seiches Seiches are waves generated in enclosed bodies of water in response to ground shaking. Based on the lack of nearby enclosed bodies of water the risk from a seiche event is not present. Tsunamis Tsunamis are waves generated in large bodies of water as a result of change of seafloor topography caused by tectonic displacement or landslide. Based on the City of Newport Beach "Potential Tsunami Runup Inundation Caused by a Submarine Landslide" map, the subject site is situated in the zone for potential tsunami run-up as shown on Plate 5, and is referenced on this plate to be areas below elevation 32 feet. For more information about tsunami run-up hazards and evacuation routes you are referred to the City website. GEOTECHNICAL DISCUSSION The site is within an area subject to liquefaction and liquefaction induced settlements under certain seismic events. Under current CBC codes, City policy, and industry standards residential structures subject to seismic hazards are designed to protect life and safety. Under this design objective the PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 8 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 requirements of protecting life and safety could be met but the structure could be damaged. The damage to the structure could range from minimal to being non-functional. The reduction of risk, for the occurrence of structural damage from a seismic event, is generally associated with the structure's foundation system. Typically the use of a conventional foundation system or a mat foundation system has been utilized in the area. Based on analysis presented within this report and City guidelines concerning liquefaction study mitigation measures the proposed structure can be developed utilizing the City's "strengthened slab on grade foundation system" for support. This type of foundation system, also referred to as a conventional foundation system, is a minimum design. As the minimum design, this foundation system has the highest risk for occurrence of structural damage to the residence. The minimum geotechnical requirements for a conventional foundation system are as follows: (1) the structure shall be placed on a mat of compacted fill soil, (2) bottom of all footings shall be 24 inches below grade, (3) foundations shall be continuous or tied together with grade beams, (4) foundations shall be reinforced with a minimum of four #5 bars, two top and two bottom, (5) concrete slabs shall be a minimum of five inch actual thickness with #4 bars at 12 inches on center each way, and (6) footings shall be dowelled into slabs with #4 bars at 24 inches on center. Additional reinforcement may be required if the structural engineer's design is more stringent. An alternate foundation system typically utilized is a structural mat foundation, which is more rigid than a conventional foundation system, and should be more effective in reducing the risk of structural damage to a structure during a seismic event. Where a mat slab foundation is planned, the slab should be at least twelve inches thick with perimeter footing a minimum of 24 inches below the lowest adjacent grade. Reinforcement shall be determined by the structural engineer. If the risk associated with either of these foundation systems is not acceptable to the client, the client has the option of utilizing more stringent designs that could decrease the risk of damage to the structure to a level they perceive as acceptable. Some of these designs could consist o_f soil modifications, grout densification, stone columns, piles placed below liquefiable soils, and other methods. Additional geotechnical exploration and or analysis would be required to provide geotechnical design recommendation for these mitigation measures, and would be at the request of the client under separate contract. Grading will be required for support of new foundations as stated within this report. Development of the site as proposed is considered feasible from a soils engineering standpoint, provided that the recommendations stated herein are incorporated in the design and are implemented in the field. The proposed grading and or construction will not have an adverse effect on adjacent property or vice versa, provided site work is performed in accordance with the guidelines of project geotechnical reports, approved plans, applicable codes, industry standards, City inspections, and required geotechnical observation and testing. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 9 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 The following recommendations are subject to change based on review of final foundation and grading plans. PROPOSED GRADING Grading plans were not available at the time this report was prepared. It is anticipated that grading will consist mainly of over-excavation and recompaction for uniform support of the foundations and slabs. GENERAL GRADING NOTES All existing structures shall be demolished and all vegetation and debris shall be stripped and hauled from the site. The entire grading operation shall be done in accordance with the attached "Specifications for Grading". Any import fill materials to the site shall not have an expansion index greater than 20, and shall be tested and approved by our laboratory. Samples must be submitted 48 hours prior to import. Grading and/or foundation recommendations are subject to modification upon review of final plans by the Geotechnical Engineer. Please submit plans to COAST GEOTECHNICAL, Inc. when available. GRADING RECOMMENDATIONS Removal and recompaction of existing earth materials will be required to provide adequate support for foundations and site improvements. Earthwork for foundation support shall include the entire building pad and shall extend a minimum of three feet outside exterior footing lines. Based on in place densities and consolidation tests, soils found at a depth of three feet below existing grade and deeper have adequate geotechnical properties to provide adequate support of proposed fills and the structure; as such, removals to a depth of three feet below existing grade or to one foot below proposed footing bottoms, whichever is greater, are anticipated; however, field observations made at the time of grading shall determine final removal limits. To provide adequate support along property lines excavations shall be sloped at a 1:1 (H:V) gradient from property line down to the excavation bottom. As fill soils are placed the grading contractor shall bench into the 1: 1 construction cut to final grade. Temporary excavations along property lines are shown on Plate 4. During earthwork operations, a representative of COAST GEOTECHNICAL, INC. shall be present to verify compliance with these recommendations. Subsequent to approval of the excavation bottom, the area shall be scarified six inches, moisture conditioned as needed, and compacted to a minimum of 90% relative compaction. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 10 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 Fill soils shall be placed in six to eight inch loose lifts, moisture conditioned as needed, and compacted to a minimum of 90% relative compaction. This process shall be utilized to finish grade. Due to the caving nature of the on-site sands, it is highly recommended that the upper two feet of fill be mixed with cement to reduce, but not eliminate, the potential of caving of the foundation excavations. Typically, a 2-3% by volume mixture of cement is sufficient to reduce the caving potential of foundation excavations. Preventing the foundation excavations from being surcharged by foot traffic and equipment will also help to reduce caving potential. Grading for hardscape areas shall consist of removal and recompaction of loose surficial soils. Removal depths are estimated at one to two feet. Earthwork shall be performed in accordance with previously specified methods. FOUNDATIONS -RESIDENCE The proposed structures shall be supported by a mat foundation or a conventional foundation system. Conventional foundations shall utilize spread footings and/or isolated pad footings placed a minimum depth of 24 inches below lowest adjacent grade utilizing an allowable bearing value of 1,800 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. The structural engineer's reinforcing requirements should be followed if more stringent. Calculations for the bearing capacity are provided on Plate G. Where isolated pads are utilized, they shall be tied in two directions into adjacent foundations with grade beams. Footing excavations shall be observed by a representative of COAST GEOTECHNICAL, INC., prior to placement of steel or concrete to verify competent soil conditions. If unacceptable soil conditions are exposed mitigation will be recommended. Geotechnical recommendations for foundation reinforcement are given under the liquefaction section of this report. If a mat slab design is utilized, the structural engineer should design the thickness and reinforcement requirements for the mat foundation for the building based on the anticipated loading conditions. The mat foundation slab should be at least twelve inches thick, with perimeter footings a minimum of 24 inches below the lowest adjacent grade. A modulus of sub grade reaction of 100 pci may be used in the design of the mat foundation. Reinforcement shall be determined by the structural engineer. Calculations for the subgrade reaction are provided on Plate I. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 11 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 Alternate foundations and or additional ground modification techniques, for support of the structure, can be addressed upon request of the project manager. All foundation plans are subject to review and approval of the soils engineer. All foundation bottoms shall be observed and approved by COAST GEOTECHNICAL,a Inc. prior to placement of the capillary break. FOUNDATIONS-SECONDARY STRUCTURES Property line walls, planter walls, and other incidental foundations may utilize conventional foundation design. Continuous spread footings or isolated pads placed a minimum depth of 24 inches below lowest adjacent grade may utilize an allowable bearing value of 1,500 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. Where isolated pads are utilized, they shall be tied in two directions into adjacent foundations with grade beams. Footing excavations shall be observed by a representative of COAST GEOTECHNICAL, Inc., prior to placement of steel or concrete to verify competent soil conditions. If unacceptable soil conditions are exposed mitigation will be recommended. Foundations shall be reinforced with a minimum of four #5 bars, two top and two bottom, The structural engineer's recommendations for reinforcement shall be utilized where more severe. LATERAL DESIGN Lateral restraint at the base of footings and on slabs may be assumed to be the product of the dead load and a coefficient of friction of0.35. Passive pressure on the face of footings may also be used to resist lateral forces. A passive pressure of zero at the surface of :finished grade, increasing at the rate of 300 pounds per square foot of depth to a maximum value of 3,000 pounds per square foot, may be used for compacted fill at this site. If passive pressure and friction are combined when evaluating the lateral resistance, then the value of the passive pressure should be limited to 2/3 of the values given above. Calculations are provided on Plate H. BULKHEAD UPGRADE It is our understanding that the existing bulkhead will be upgraded. The following design values may be utilized: Bearing Value Passive Pressure Coefficient of Friction 1,800 psf & 1,200 psf submerged 300 psf/ft & 160 psf/ft submerged 0.35 PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir Geotechnical Engineering Investigation Soil Parameters Unit weight= 125 pcf (saturated) Cohesion = 100 pcf Angle of internal Friction = 31 ° 12 w. 0. 600320-01 August 13, 2020 Walls unrestrained from deflection should be designed for active earth pressures. For the level backfill conditions, an equivalent fluid pressure of 31.5 pounds per cubic foot may be used for design. Calculations are provided on Plate J. Walls restrained from deflection should be designed for "at-rest" earth pressures. For the level backfill conditions, an equivalent fluid pressure of 53.3 pounds per cubic foot may be used for design. Calculations are provided on Plate L. The surcharge pressure of adjacent buildings should be added to these soil pressures. Code requires that retaining walls with more than six feet of backfill be designed for seismic loads. For a retaining wall under earthquake loading the designed equivalent fluid pressure is sensitive to the ground motion value applied to analysis. Our understanding is that the current reviewer for the City of Newport Beach utilizes Sos for the ground motion and allows the consulting engineer to utilize his allowed reduction to determine the seismic coefficient Kh. Calculations for determining Kh for restrained and unrestrained conditions are appended on Plate K. For unrestrained conditions a Kh value of 0.222 was determined. Use of this value in a simplified analysis method allowed by the reviewer, determines that a seismic load of 18.3 pcf should be utilized by the structural engineer. For restrained conditions a Kh value of 0.377 was determined. Use of this value in a simplified analysis method, determines that a seismic load of 31.1 pcf should be utilized by the structural engineer. FLOOR SLABS Slab on grades shall be designed in accordance with current CBC codes. Site soils are non plastic. Minimum geotechnical recommendations for slab design are five inches actual thickness with #4 bars at 12 inches on center each way. Slabs shall be tied into perimeter foundations with #4 bars at 24 inch centers. Structural design may require additional reinforcement and slab thickness. Sub grade soils shall exhibit a minimum relative compaction of 90% to the depth determined by the geotechnical engineer. The soil should be kept moist prior to casting the slab. However, if the soils at grade become disturbed during construction, they should be brought to approximately optimum moisture content and rolled to a firm, unyielding condition prior to placing concrete. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 13 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 COAST GEOTECHNICAL, Inc. to verify adequacy of subgrade soils prior to placement of capillary break or vapor barrier. Section 4.505.2.1 of the California Green Code requires the use of a capillary break between the slab subgrade and vapor barrier. The capillary break material shall comply with the requirements of the local jurisdiction and shall be a minimum of four inches in thickness. Geotechnically coarse clean sand is acceptable; however, some localities require the use of four inches of gravel (1/2-inch or larger clean aggregate). If gravels are used, a heavy filter fabric (Mirafi 140N) shall be placed over the gravels prior to placement of the recommended vapor barrier to minimize puncturing of the vapor barrier. Additionally, a vibratory plate should be used over the gravels prior to placement of the recommended filter fabric to smooth out any sharp protuberances and consolidate the gravels. Slab areas should be underlain by a vapor retarder consisting of an engineered plastic film (as described by ASTM:E-1745). In areas where a moisture sensitive floor covering will be used and/or where moisture infiltration is not desirable, a vapor barrier with a permeance of less than 0.0lperms (consistent with ACI 302.2R-06) such as 15 mil. Stego Wrap Vapor Barrier, or equivalent, should be considered, and a qualified water proofing specialist should be consulted. The vapor barrier should be underlain by the above described capillary break materials and filter cloth. The capillary break materials should be compacted to a uniform condition prior to placement of the recommended filter cloth and vapor barrier. The vapor barrier should be properly lapped and sealed. SEISMIC DESIGN Based on the current CBC and ASCE 7-16, the following seismic design parameters are provided. These seismic design values were determined utilizing latitude 33.61369 and longitude -117.91732 and calculations from the SEAOC/OSHPD Seismic Design Tool. Data output is attached in Appendix B. A conservative site class D was assigned to site earth materials. • Site Class = D • Mapped 0.2 Second Spectral Response Acceleration, Ss = 1.385g • Mapped One Second Spectral Response Acceleration S1 = 0.493g • Site Coefficient from Table 1613A5.3(1), Fa= 1.2 • Site Coefficient from Table 1613A5.3(2), Fv = 1.807 • Maximum Design Spectral Response Acceleration for short period, SMs = 1.662g • Maximum Design Spectral Response Acceleration for one-second period, SM1 = 0.891g • 5 % Design Spectral Response Acceleration for short period, Sns = 1.108 g • 5% Design Spectral Response Acceleration for one-second period, Sm = 0.594g SETTLEMENT The maximum total post-construction static settlement is anticipated to be on the order of 1/2 inch. Differential settlements are expected to be less than 1/2 inch, measured between adjacent structural elements over a distance of 40 feet. Seismic induced settlements are addressed under previous sections. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 14 Geotechnical Engineering Investigation SUBSIDENCE & SHRINKAGE w. 0. 600320-01 August 13, 2020 Subsidence over the site is anticipated to be negligible. Shrinkage of reworked materials should be in the range of 5 to 10 percent. EXPANSIVE SOILS Results of expansion tests indicate that the near surface soils have a very low expansion potential. UTILITY LINE BACKFILLS All utility line backfills, both interior and exterior, shall be compacted to a mmnnum of 90% relative compaction and shall require testing at a maximum of two-foot vertical intervals. Utility lines shall be placed at appropriate depths. Shallow pipes can be damaged by the forces imposed by compacting backfill soils. If shallow pipes are not capable of withstanding the forces of backfill compaction, slurry backfill will be recommended. HARDSCAPE AND SLABS Hardscape and slab sub grade areas shall exhibit a minimum of 90% relative compaction to a depth of at least one foot. Deeper removal and recompaction may be required if unacceptable conditions are encountered. These areas require testing just prior to placing concrete. Hardscape shall be at least four inches thick and reinforced with #3 bars on 18 inch centers both ways. CHEMICAL ANALYSIS An on-site soil sample showed a soluble sulfate content of 49 ppm, which is a negligible sulfate exposure. Concrete with Type II 2,500 psi may be utilized; however, the saltwater environ may cause damage to exposed concrete and a designed concrete should be considered. DRAINAGE Positive drainage should be planned for the site. Drainage should be directed away from structures via non-erodible conduits to suitable disposal areas. The structure should utilize roof gutters and down spouts tied directly to yard drainage. Pipes used for storm/site water drainage should be stout enough to withstand the force of compaction of the soils above. This force can be considerable, causing some weaker pipes to collapse. Drainage pipes shall have a smooth interior. Pipes with a corrugated interior can cause the buildup of deleterious matter, which can impede or block the flow of site waters and, as such, are not recommended. All storm/site water drainage pipes should be in conformance with the requirements from the current California Plumbing Code. Unlined flowerbeds, planters, and lawns should not be constructed against the perimeter of the structure. If such landscaping ( against the perimeter of a structure) is planned, it should be properly PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 15 Geotechnical Engineering Investigation w. 0. 600320-01 August 13, 2020 drained and lined or provided with an underground moisture barrier. Irrigation should be kept to a minimum. The current CBC recommends five percent slope away from structures for landscape areas within ten feet of the residence. Hardscape areas shall be sloped a minimum of two percent where within ten feet of the residence unless allowed otherwise by the building official. Minimum drainage shall be one percent for hardscape areas and two percent for all other areas. We do not recommend the use of infiltration best management practice (BMP) such as infiltration trenches, bottomless trench drains infiltration basins, dry wells, permeable pavements or similar systems designed primarily to percolate water into the subsurface soils within five feet of foundations. Due to the physical characteristics of the site earth materials, infiltration of waters into the subsurface earth materials has a risk of adversely affecting below grade structures, building foundations and slabs, and hardscape improvements. From a geotechnical viewpoint surface drainage should be directed to the street. The WQMP requirement shall be addressed by the Civil Engineer. ENGINEERING CONSULTATION, TESTING & OBSERVATION We will be pleased to provide additional input with respect to foundation design once methods of construction have been determined. Grading, foundation and shoring plans should be reviewed by this office prior to commencement of grading so that appropriate recommendations, if needed, can be made. Areas to receive fill should be observed when unsuitable materials have been removed and prior to placement of fill. Fill should be observed and tested for compaction as it is placed. SUPPLEMENTAL CONSULTING During construction, a number of reviews by this office are recommended to verify site geotechnical conditions and conformance with the intentions of the recommendations for construction. Although not all possible geotechnical observation and testing services are required. The following site reviews are advised, some of which will probably be required by the City of Newport Beach: • Grading and excavations review for main structures • Foundation excavations • Slab subgrade compaction testing prior to placement of the capillary break or waste slab • Slab steel placement, primary and appurtenant structures • Compaction ofutility trench backfill • Hardscape subgrade compaction PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 16 Geotechnical Engineering Investigation AGENCY REVIEW w. 0. 600320-01 August 13, 2020 All soil, geologic and structural aspects of the proposed development are subject to the review and approval of the governing agency(s). It should be recognized that the governing agency(s) can dictate the manner in which the project proceeds. They could approve or deny any aspect of the proposed improvements and/or could dictate which foundation and grading options are acceptable. Supplemental geotechnical consulting in response to agency requests for additional information could be required and will be charged on a time and materials basis. LIMITATIONS This report presents recommendations pertaining to the subject site based on the assumption that the subsurface conditions do not deviate appreciably from those disclosed by our exploratory excavations. Our recommendations are based on the technical information, our understanding of the proposed construction, and our experience in the geotechnical field. We do not guarantee the performance of the project, only that our engineering work and judgments meet the standard of care of our profession at this time. In view of the general conditions in the area, the possibility of different local soil conditions may exist. Any deviation or unexpected condition observed during construction should be brought to the attention of the Geotechnical Engineer. In this way, any supplemental recommendations can be made with a minimum of delay necessary to the project. If the proposed construction will differ from our present understanding of the project, the existing infonnation and possibly new factors may have to be evaluated. Any design changes and the finished plans should be reviewed by the Geotechnical Consultant. Of particular importance would be extending development to new areas, changes in structural loading conditions, postponed development for more than a year, or changes in ownership. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are called to the attention of the Architects and Engineers for the project, and incorporated into the plans and that the necessary steps are taken to see that the contractors and subcontractors carry out such recommendations in the field. This report is subject to review by the controlling authorities for this project. We appreciate this opportunity to be of service to you. Respectfully submitted: COAST GEOTECHNICAL, INC ~:-fo.--t~ W<d40'1 Ming-Tamg Chen ff.i,q;i,.1:i;/JH::::1 RCE 54011 ,~Cf Vt\~,/ ~~,_~!·.~t~~·-· ~ ,' PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 17 Geotechnical Engineering Investigation APPENDIXA w. 0. 600320-01 August 13, 2020 This appendix contains a description of the field investigation, laboratory testing procedures and results, site plan, exploratory logs and expansive soil recommendations. FIELD INVESTIGATION The field investigation was performed on July 29, 2020, consisting of the excavations of a boring by a limited access drilling equipment (for Boring No. 1) and a boring by hand auger equipment (for Boring No. 2) at the locations shown on the attached Site Plan, Plate 2. As drilling progressed, personnel from this office visually classified the soils encountered, and secured representative samples for laboratory testing. Description of the soils encountered is presented on the attached Boring Logs. The data presented on this log is a simplification of actual subsurface conditions encountered and applies only at the specific boring location and the date excavated. It is not warranted to be representative of subsurface conditions at other locations and times. LABORATORY TESTING Field samples were examined in the laboratory and a testing program was then established to develop data for preliminary evaluation of geotechnical conditions. Field moisture and dry densities were calculated for each undisturbed sample. The samples were obtained per ASTM:D-2937 and tested under ASTM:D-2216. Maximum density-optimum moisture relationships were established per ASTM:D-1557 for use in evaluation of in-situ conditions and for future use during grading operations. Direct shear tests were performed in accordance with ASTM:D-3080, on specimens at near saturation under various normal loads. The results of tests are based on an 80% peak strength or ultimate strength, whichever is lower, and are attached as Plates E and F. Expansion tests were performed on typical specimens of natural soils in accordance with the procedures outlined in ASTM:D-4829. A consolidation test was performed on representative samples based on ASTM:D-2435. The consolidation plot is presented on Plate D. PA2021-012 COAST GEOTECHNICAL, INC. Mr. and Mrs. John Devir 18 Geotechnical Engineering Investigation TEST RESULTS w. 0. 600320-01 August 13, 2020 Maximum Density/Optimum Moisture (ASTM: D-1557) Boring Depth in Feet Maximum Density, Optimum Moisture, % pcf 1 0-5 112.0 10.5 Direct Shear (ASTM: D3080) Boring Depth in Feet Cohesion Angle of Internal Friction Obs./sq. ft.) (Degrees) 1 0 - 5 (remolded) 100 31 2 3 50 31 Expansion Index (ASTM: D4829) Boring Depth in Feet Expansion Index Expansion Potential 1 0-5 0 Very Low Soluble Sulfate Analysis (ASTM:D516) Boring Depth in Feet Soluble Sulfate (ppm) 1 0-5 49 PA2021-012 COAST GEOTECHNICAL, INC. SPECIFICATIONS FOR GRADING SITE CLEARJNG All existing vegetation shall be stripped and hauled from the site. PREPARATION After the foundation for the fill has been cleared, plowed or scarified, it shall be disced or bladed until it is uniform and free from large clods, brought to a proper moisture content and compacted to not less than ninety percent of the maximum dry density in accordance with ASTM:D-1557 (5 layers -25 blows per layer; 10 lb. hammer dropped 18"; 4" diameter mold). MATERIALS On-site materials may be used for fill, or fill materials shall consist of materials approved by the Soils Engineer and may be obtained from the excavation of banks, borrow pits or any other approved source. The materials used should be free of vegetable matter and other deleterious substances and shall not contain rocks or lumps greater than six inches in maximum dimension. PLACING, SPREADING AND COMPACTING FILL MATERIALS The selected fill material shall be placed in layers which, when compacted, shall not exceed six inches in thickness. Each layer shall be spread evenly and shall be thoroughly mixed during the spreading to ensure uniformity of material and moisture of each layer. Where moisture of the fill material is below the limits specified by the Soils Engineer, water shall be added lmtil the moisture content is as required to ensure thorough bonding and thorough compaction. Where moisture content of the fill material is above the limits specified by the Soils Engineer, the fill materials shall be aerated by blading or other satisfactory methods until the moisture content is as specified. After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than 90 percent of the maximum dry density in accordance with ASTM:D-1557 (5 layers -25 blows per layer; 10 lbs. hammer dropped 18 inches; 4" diameter mold) or other density tests which will attain equivalent results. Compaction shall be by sheepfoot roller, multi-wheel pneumatic tire roller, track loader or other types of acceptable rollers. PA2021-012 COAST GEOTECHNICAL, INC. SPECIFICATIONS FOR GRADING PAGE2 Rollers shall be of such design that they will be able to compact the fill to the specified density. Rolling shall be accomplished while the fill material is at the specified moisture content. Rolling of each layer shall be continuous over the entire area and the roller shall make sufficient trips to ensure that the desired density has been obtained. The final surface of the lot areas to receive slabs on grade should be rolled to a dense, smooth surface. The outside of all fill slopes shall be compacted by means of sheepfoot rollers or other suitable equipment. Compaction operations shall be continued until the outer nine inches of the slope is at least 90 percent compacted. Compacting of the slopes may be progressively in increments of three feet to five feet of fill height as the fill is brought to grade, or after the fill is brought to its total height. Field density tests shall be made by the Soils Engineer of the compaction of each layer of fill. Density tests shall be made at intervals not to exceed two feet of fill height provided all layers are tested. Where the sheepfoot rollers are used, the soil may be disturbed to a depth of several inches and density readings shall be taken in the compacted material below the disturbed surface. When these readings indicate that the density of any layer of fill or portion there is below the required 90 percent density, the particular layer or portion shall be reworked until the required density has been obtained. The grading specifications should be a part of the project specifications. The Soil Engineer shall review the grading plans prior to grading. INSPECTION The Soil Engineer shall provide continuous supervision of the site clearing and grading operation so that he can verify the grading was done in accordance with the accepted plans and specifications. SEASONAL LIMITATIONS No fill material shall be placed, spread or rolled during 1mfavorable weather conditions. When heavy rains interrupt work, fill operations shall not be resumed until the field tests by the Soils Engineer indicate the moisture content and density of the fill are as previously specified. EXPANSIVE SOIL CONDITIONS Whenever expansive soil conditions are encountered, the moisture content of the fill or recompacted soil shall be as recommended in the expansive soil recommendations included herewith. PA2021-012 SITE VICINITY MAP 39 Geotechnical Engineering Investigation 508 Via Udo Nord Newport Beach, California UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGIC SURVEY Work Order 600320 Plate No. 1 COAST GEOTECHN/CAL, INC. PA2021-012 ~~ N& HlllfTINlflllNB~DH111AUFIIR IA\12446 PIIIJNE~71414BHDCl6FIJ(1!714J33a-444II AP!XLSINll@GMAIL..CIJM !l~ !;;§ 8~ ,\ :e tri e SITE PLAN -l 2 Via Lido Nord Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California Scale: 1" :::: 16' C Work Order 600320 Plate No. 2 COAST GEOTECHNICAL, INC. PA2021-012 SEISMIC HAZARD ZONES MAP Delineated In compliance with Chapter 7.8, Dlvi!lion 2 of the Callfomle Public Resources Code {Sdlsmlc Haards-MIIPPfng A,:tJ . NEWPORT BEACH QUADRANGLE OFFICIAL MAP Liquefaction Zone Released: April?, 1997 Landslide Zone Released: April 15, 1998 45 39 Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California MAP EXPLANATION Zones of Required Investigation: Liquefaction Areas wh~re historic occurrence of liquefaction, or local geolOgical, geotechnrcal and groundwater conditions lndicate·a potential for permanent g_round displacements such that mitigation as defined in. Public Resources Code Section 2693(c) would be required. · E,arthquak&--lnducad Landslides Areas where previous occurrence of landslide movement or local topographic, geolog/cal, geotechnical and subsurface water conditions Indicate a potential for permanent ground dlsplacements such that mitigation as def_ined In Public Resources Code Section 2693(c} would be required. Work Order 600320 Plate No. 3 COAST GEOTECHNICAL, INC. PA2021-012 TEMPORARY EXCAVATION ALONG PROPERTY LINES BUILDING FACE --- F.F. NEW ~ FOOTING---. (24") 1!11 IQ II s ~ / 4 / / / SCALE: 1''~ 2' WALL ORP.L. v/ /I / // l~EMPORARY 1------.Y SLOPE /: / // : ~ BENCHING 7 ---___ ,L ______ i,)I ~ 1:1 PROJECTION OVER-EXCAVATION This plate is not a representation of actual site conditions. It is a general representation of typical conditions and intended for the illustration of geotechnical data only. The indicated scale is approximate, and to be used for rough measurement only. Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate No. 4 COAST GEOTECHNICAL, INC. PA2021-012 POTENTIAL TSUNAMI RUNUP INUNDATION CAUSED BY A SUBMARINE LANDSLIDE /' / ,, "' ,,."' , ... ,., ,. ,, " ... , "." ,_ B.a,e Map: uses To p:,gr.aph ic Map from Sure! MAPS RASTER ' Source: City of Ncewp:, rt Be...: h, 2007 baied on un pu bli, hed ' re«:::.arc h by J. C. Bo rn::ro .and others .at Un iven ity of ,, Southern C.alifurn i.a ,, "' NOTES: This. Miilp i; inR::nd,;d tor zwi,;:ral l:a.nd u~ pla.nn ing only. Ink. m,a.tio nan t hi: m:ap i!ii rd s!Mici.:rt bl si;:rAi: il!ii a. Siub:tittu: fear dlil:a.i~ ~b,tic jrr,,'l;;Sjj: pl:io rriii cf individual sil:,;s;. oor dQoQSii it satisfy th-.: Q',,jl,lua.tion l'G:(lU ip;;m-.:rt!ii:;;:t forth in z«alcazic 1-R.za.rd rQZUlat ion!ii. .. , "· . Ruth Cc.1"Eiiiub.ntsi lrkrna.tDnal(EC::(I ma.loil:Si no f'!Qf)~ntltion. or........,rantt&l5 ~dinz th;: a.o::u ia.cy d t 1G: datia. from which t~,;: map!ii w,;:r,;; d,;;~. EC l5ihi1.II not b;: liabl;; un:1-.:r •l"Pf ci ,:u l'i?iil:iil.rta!!ii for ii.IT/ d ir«:t,. indi flii:i:t,. sp;.,,::ia.L incidci:ntaL or O:.R"1:JU;:rtia.l diia.map with~ tQanydaim by any i.m;:reirthirdpall:y.::.n iiL0:0Urtilf.,orari!iiir«; 11,m,. th<>""'ofthi, rmpj Proje:ct Num b:r: 2706 Dak:: 200 e Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California ""~· Seale: 1 :60,000 O"'.S""""""=""""'O"'.a..._..._""""""'"l,S Miler EXPLANATION Area that would be inundated bya hunami generated by a submarire landslide ofM-.ore of Newport Beach (areas at or lovver than 3 2 foot elevation N9wport Beach City Boundary Sphere of Influence Work Order 600320 Plate No. 5 COAST GEOTECHNICAL, INC. PA2021-012 UNIFIED SOIL CLASSIFICATION AND KEY TO BORING LOGS UNITED SOIL CLASSIFICATION SYSTEM (ASTM D-2487) PRIMARY DIVISIONS SYMBOLS SECONDARY DIVISIONS GW WELL-GRADED GRAVELS, GRAVEL-SAND MIXTURES, LITTLE GRAVEL AND CLEAN GRAVELS ORNO FINES GRAVELLY (LITTLE OR NO SOILS FINES) GP POORLY-GRADED GRAVELS, GRAVEL-SAND MIXTURES, COARSE LITTLE OR NO FINES GRAINED SOILS MORE THAN 50% OF COARSE GRAVELS WITH GM SIL TY GRAVELS, GRAVELS-SAND-SILT MIXTURES FRACTION FINES RETAINED ON (APPRECIABLE NO.4SIEVE AMOUNT OF FINES) GC CLAYEY GRAVELS, GRAVELS-SAND-CLAY MIXTURES SW WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO SAND AND CLEAN SAND FINES SANDY SOILS (LITTLE OR NO MORE THAN 50% FINES) SP POORLY-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO OF MATERIAL IS FINES LARGER THAN NO. MORE THAN 50% 200 SIEVE SIZE OF COARSE SAND WITH SM SIL TY SANDS, SAND-SILT MIXTURES FRACTION FINES PASSING NO. 4 (APPRECIABLE SIEVE AMOUNT OF FINES) SC CLAYEY SANDS, SAND-CLAY MIXTURES INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, ML SIL TY OR CLAYEY FINE SANDS OR CLAVEY SIL TS WITH SLIGHT PLASTICITY FINE GRAINED SILTS AND LIQUID LIMIT INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, SOILS CLAYS LESS THAN 50 CL GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS OL ORGANIC SIL TS AND ORGANIC SIL TY CLAYS OF LOW PLASTICITY MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE MORE THAN 50% SAND OR SIL TY SOILS OF MATERIAL IS SILTS AND LIQUID LIMIT SMALLER THAN CLAYS GREATER THAN CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS NO. 200 SIEVE 50 SIZE OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SIL TS HIGHLY ORGANIC SOILS PT ORGANIC SIL TS AND ORGANIC SIL TY CLAYS OF LOW PLASTICITY COARSE GRAINED SOILS FINE GRAINED SOILS CONSISTENCY BLOWS/FT" CONSISTENCY BLOWS/FT" VERY LOOSE 0-4 VERY SOFT 0-2 LOOSE 4-10 SOFT 2-4 MEDIUM DENSE 10 • 30 FIRM 4-8 DENSE 30 • 50 STIFF 8-15 VERY DENSE OVER50 VERY STIFF 15-30 HARD OVER30 * BLOWS/FT FOR A 140-POUND HAMMER FALLING 30 INCHES TO DRIVE A 2 INCH O.D., 1-3/8 INCH I.D. SPLIT SPOON SAMPLER (STANDARD PENETRATION TEST) KEY TO SAMPLE TYPE: U = UNDISTURBED SAMPLE B = BULK S = SPT SAMPLE COAST GEOTECHNICAL, INC. PA2021-012 COAST GEOTECHNICAL, INC. (Text Supercedes) PLATEA 12" 12" 12" 15" 15" 15" 15" 15" 15" 15" 18" 18" 18" 18" 18" 24" 24" 24" 24" 30" 24" 24" 24" 24" 36" 24" 24" 24" 24" 36" 24" 24" 24" 24" 36" 4 #5 Bars 4 #5 Bars 4 #5 Bars 4 #5 Bars 4 #5 Bars 2 Top 2Top 2Top 2 Top 2 Top 2 Bottom 2 Bottom 2 Bottom 2 Bottom 2 Bottom 5"Nominal 5" Nominal 5"Nominal 5" Actual 5" Actual #4Bars on #4Bars on #4 Bars on #4 Bars on #4 Bars on 12" 12" 12" 12" 12" Centers Centers Centers Centers Centers Both Ways Both Ways Both Ways Both Ways Both Ways 15 mil 15 mil 15 mil 15 mil 15 mil Vapor Vapor Vapor Vapor Vapor Barrier Barrier Barrier Barrier Barrier 2" Sand 2" Sand 2" Sand 2" Sand 2" Sand #4Bars on #4 Bars on #4 Bars on #4 Bars on #4 Bars on 12" 12" 12" 12" Center 12" Center Centers Centers Centers Both Ways Both Ways Both Ways Both Ways Both Ways Free Floating Free Floating Same as Same as Same as Same as Same as Adj. Ext. Adj. Ext. Adj. Ext. Adj. Ext. Adj. Ext. Ftg. Ftg. Ftg. Ftg. Ftg. 4" Clean 4" Clean 4" Clean 4" Clean 4" Clean Aggregate Aggregate Aggregate Aggregate Aggregate (1/2 inch or (1/2 inch or (1/2 inch or (1/2 inch or (1/2 inch or larger) larger) larger) larger) larger) Above Opt. To 110% of 130% of Opt 130% of Opt Depth of Ftg. Opt MIC to M/Cto Depth MIC to Depth (No Testing) Depth Footing Footing Footing 1. The surrounding areas should be graded so as to ensure drainage away from the building. 2. Concrete floor slab in areas to be covered with moisture sensitive coverings shall be constructed over a 15 mil Stego Wrap or equivalent. The plastic should be properly lapped, sealed and protected filter fabric (Mirifi 140N) and sand. 3. Two inches of sand over moisture barrier in addition to the four-inches of clean aggregate below the membrane. PA2021-012 Date: Q) I-.2 a. ro Cl) > z 18 12 19 25 22 SUMMARY OF BORING NO. 1 7/29/2020 Elevation: E.G. +-' C: !/) Q) Q) 0 C: Q) u:: a. 4 3 5 7 9 -!/) -~ ~~ Q) ~ C: 0.. LL L.. Q) -0 in ~ E Description +-' ..c: 0 !/) ·5 Cl ro +-' "in Cl) a. 0 ~~ Q) C: Cl 0 -B U 0 ( 8" Concrete) FILL: SAND ---silty, fine-grained, dry to damp with Tan to Tan Loose shells Brown NATIVE: SAND ---clean, fine to medium-grained, Tan Medium damp Dense 4.4 5 5.1 SAND ---clean, fine to medium-grained, damp Tan to Gray Medium Tan Dense 12.5 SAND ---clean, fine to medium-grained, moist Tan to Gray Medium Tan Dense 22.8 SAND ---slightly silty, fine to medium-grained, Light Gray to Medium 10 wet Gray Dense 22.3 SAND ---slightly silty, fine to medium-grained, Gray Medium wet Dense End of boring at 12.5 feet Groundwater at 9.0 feet Sands are subject to caving 15 Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate B COAST GEOTECHNICAL, INC. PA2021-012 Date: 7/29/2020 ~ -(/) -"iii ~~ Q) _: a. LL C: --©u 1n ~ E ..c: 0 0. ·5 0 ctl -~-CJ) a. ~ '?f2. (I) 0 -0 U B 2 97.7 5.7 4 100.9 12.3 6 100.5 14.4 8 10 SUMMARY OF BORING NO. 2 Elevation: E.G. ~ C: ... 0 (I) Description -0 (/) "iii C) C: 0 C) FILL: SILT ---sandy, dry, with minor roots Dark Brown Loose NATIVE: SAND ---clean, fine to medium-grained, Light Tan to Medium damp Gray Tan Dense SAND ---slightly silty, fine -grained, damp to moist SAND ---clean, medium to coarse -grained, moist to very moist End of boring at 9.0 feet Groundwater at 8.5 feet Sands are subject to caving Tan to Gray Medium Tan Dense Tan to Gray Medium Tan Dense Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate C COAST GEOTECHNICAL, INC. PA2021-012 CONSOLIDATION TEST RESULTS [ Boring No.2 @ 3.0 Feet l Pressure (Kips Per Square Foot) 0.1 1 10 0.00 v--. --l ~- ~ 1.00 ........ -............. .__ ........... ~-u. 2.00 ....... ....... _,___ ....... --' --....... -, 3.00 --C Cl) ~ 4.00 Cl) C. -C 0 5.00 :;::; co :E 0 1/) 6.00 C 0 (.) 7.00 8.00 9.00 10.00 0 Test Specimen at In-Situ Moisture • Test Specimen Submerged Geotechnical Engineering Investigation Work Order 600320 508 Via Lido Nord Newport Beach, California Plate No. D COAST GEOTECHNICAL, INC. PA2021-012 SHEAR TEST RESULT [ Boring No.1 @Oto 5 Feet (Remolded to 90%) ) (/) (/) 5 4 ~ 2 ci5 0 0 1 2 3 4 Confining Pressure (kips/sq. ft.) Remolded soil samples were tested at saturated conditions. 5 The sample had a dry density of 100.7 lbs./cu.ft. and a moisture content of 24.7 %. Cohesion = 100 psf Friction Angle = 31 degrees Based on 80% peak strength or ultimate strength, whichever is lower Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate No. E COAST GEOTECHNICAL, INC. PA2021-012 SHEAR TEST RESULT ( Boring No. 2 @ 3.0 feet l 5 4 0 1 2 3 4 5 Confining Pressure (kips/sq. ft.) Native soil samples were tested at saturated conditions. The sample had a dry density of 97.7 lbs./cu.ft. and a moisture content of 25.3 %. Cohesion = 50 psf Friction Angle = 31 degrees Based on 80% peak strength or ultimate strength, whichever is lower Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate No. F COAST GEOTECHNICAL, INC. PA2021-012 ALLOWABLE BEARING CAPACITY Bearing Capacity Calculations are based on "Terzaghi's Bearing Capacity Theory" Bearing Material: Compacted Fill Properties: Wet Density (y) = 110 pcf Cohesion (C) = 100 psf Angle of Friction (¢) = 31 degrees Footing Depth (D) = 2 feet Footing Width (8) = 1.3 feet Factor of Safety = 3.0 Calculations -Ultimate Bearing Capacity from Table 3.1 on page 127 of "Foundation Engineering Handbook", 1975 Ne= 32.67 Nq = 20.63 Nr = 25.99 Ou = 1.3 C Ne + y D Nq + 0.4 y B Ny (Square Footing) = 1.3 * 100 * 32.67 + 110 * 2 * 20.63 + 0.4 * 110 * 1.25 * 25.99 = 4247 + 4538 + 1429 = 10214 psf Allowable Bearing Capacity for Square Footing Oa11= Ou/ F.S. = Use 1800 psf 3404 psf Ou = 1.0 C Ne+ y D Nq + 0.5 y B Ny (Continuous Footing) = 1.0 * 100 * 32.67 + 110 * 2 * 20.63 + 0.5 * 110 * 1.25 * 25.99 = 3267 + 4538 + 1786 = 9591 psf Allowable Bearing Capacity for Continuous Footing Oa11= Ou/ F.S. = Use 1800 psf 3197 psf Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate G COAST GEOTECHNICAL, INC. PA2021-012 LATERAL EARTH PRESSURE CALCULATIONS Retaining structures such as retaining walls, basement walls, and bulk-heads are commonly used in foundation engineering, and they support almost vertical slopes of earth masses. Proper design and construction of these structures require a through knowledge of the lateral forces acting between the retaining structures and the soil masses being retained. These lateral forces are due to lateral earth pressure. Properties of earth material: Compacted fill Wet Density (y) Cohesion (C) = = 110 pcf 100 psf Angle of Friction (<P) = 31 degrees Coefficient of Friction = tan <I> Therefore, Coefficient of Friction = tan <I> = tan <jJ = 0.601 Assumed H = 2 feet Use 0.35 Pp= 0.5 y H2 tan2 ( 45° + <jJ 12 ) + 2 CH tan ( 45° + <jJ 12) = 0.5*110*4*3.122+2*100*2*1.767 = 687 + 707 = 1394 lbs/ LF 1/2 EFP H2 = 1394 EFP = 697 psf / LF EFP: passive pressure Allowable Passive Pressure= 300 psf / LF ( with F.S. = 2.32) Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate H COAST GEOTECHNICAL, INC. PA2021-012 CALCULATION OF SUBGRADE REACTION Subgrade reaction calculations are based on "Foundation Analysis and Design" Fourth Edition, by Joseph E. Bowles. Ks= 24 qu1t(for ~H = 1/2 inch) Where: Ks = subgrade reaction in k / ft3 quit = ultimate bearing capacity For qu1t = 9.6 ksf (from bearing capacity calculations) Ks = 24 * 9.59 k / ft3 = 230.2* 1000 I ( 12 * 12 * 12) lb/ in3 = 133.2 lb/ in3 Use 100 pound per cubic inch Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California COAST GEOTECHNICAL Work Order 600320 Plate No. I PA2021-012 ACTIVE EARTH PRESSURE BY COULOMB THEORY The total active thrust can be expressed as PA = 0.5 KA y H2 where the active earth pressure coefficient, KA, is given by cos2 (<P -0) =------------------- cos20 cos(o + 0) { 1 + [ sin(o + ¢) sin(¢ -{:J) cos(o + 0) cos({:J -0) Where: 0 = slope of the back of the wall with respect to the vertical o = angle of friction between the wall and the soil /3 = slope of the backfill with respect to the horizontal Properties of earth material: Wet Density (y) Cohesion (C) Angle of Friction(¢) 0 0 = = = = = Caculate KA based on slope of the backfill Surface Slope Slope Angle ({:J) KA Level 0.0 0.286 5:1 (H:V) 11.3 0.333 4:1 (H:V) 14.0 0.348 3:1 (H:V) 18.4 0.379 2:1 (H:V) 26.6 0.487 1.5:1 (H:V) 33.7 0.782 Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California 110 pcf 100 psf 31 degrees 0 20 EFP [ = y * KA], pcf 31.5 36.6 38.3 41.7 53.5 86.0 Work Order 600320 Plate J COAST GEOTECHNICAL, INC. PA2021-012 CALCULATION OF ~PAE Sos = 1.108 g Moist Density (v) = 110 pcf For restrained condition with level backfill Kh = 0.4 * Sos * 0.85 = 0.377 ~PAE = 3/4 y Kh = 31.1 pcf For unrestrained condition with level backfill Kh = 0.4 *Sos* 0.5 = 0.222 ~PAE = 3/4 y Kh = 18.3 pcf Geotechnical Engineering Investigation Work Order 600320 508 Via Lido Nord Newport Beach, California Plate No. K COAST GEOTECHNICAL PA2021-012 LATERAL EARTH PRESSURE CALCULATIONS Retaining structures such as retaining walls, basement walls, and bulk-heads are commonly used in foundation engineering, and they support almost vertical slopes of earth masses. Proper design and construction of these structures require a through knowledge of the lateral forces acting between the retaining structures and the soil masses being retained. These lateral forces are due to lateral earth pressure. Properties of earth material: Wet Density (y) Cohesion (C) Angle of Friction (¢) = = = 110 pcf 100 psf 31 degrees Coefficient of earth pressure at rest ( Jaky, 1944 ), KO = 1 -sin </> KO Therefore, Earth pressure at rest = y KO = 53.3 psf /LF Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California = 0.485 Work Order 600320 Plate L COAST GEOTECHNICAL, INC. PA2021-012 APPENDIXB Liquefaction Analysis by SPT Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California COAST GEOTECHNICAL, INC. PA2021-012 LIQUEFACTION ANALYSIS BY SPT FOR BORING NO. 1 CN = (Pa/ G0' )112 < 1.7, Pa= 2089 psf (N1)50 = Nm CN CE Cs CR Cs CSR= 'iav / G0' = 0.65 ( G0 I G 0') rd ( amax I g) )bt~~H"" '"";,~;;""' :~~]i;~'; , ~~,, ,,,,~;''' ,,,,~~,, ,,,~,: :·~:::~~ :!:,.: ~~~~; ::~;::: ~007;~ ,,~:,c:i,:, '''''''""'~'~"'"""> 3 315.0 315.0 18 1.10 I 1.00 I 1.05 I 0.75 I 1.20 28.9 0.99 I 0.47 4 0.40 I 1.15 I 0.46 0.98 5 525.0 525.0 12 1.10 I 1.00 I 1.05 I 0.75 I 1.20 19.3 0.99 I 0.47 3 0.22 I 1:15 I 0.25 0.54 7 755.0 692.6 19 1.70 I 1.00 I 1.05 I 0.75 I 1.20 30.5 0.99 I 0.51 5 0.60 11.151 0.69 1.35 9 1005.0 I 817.8 25 1.60 I 1.00 I 1.05 I 0.75 I 1.20 37.8 0.98 I o.57 7 0.60 I 1.15 I 0.69 1.21 11 1255.0 I 943.0 22 1.49 I 1.00 I 1.05 I 0.75 I 1.20 30.9 0.98 I 0.62 9 0.60 I 1.15 I 0.69 1.12 Note: 1. Moist unit weight of 105 pcf, saturated unit weight of 125 pcf, and groundwater at 6 feet 2. Magnitude of 7.2 and peak ground acceleration of 0.727 g 3. According to Figure 2, soil layers having (N1)60 higher than 30 are not considered liquefiable. Geotechnical Engineering Investigation I Work Order 600320 508 Via Lido Nord Newport Beach, California Plate M COAST GEOTECHNICAL, INC. PA2021-012 Open-file Report 97-08 Newport Beach L-----------------------------------------'~w SStdfl'-SP~'kl!'t'I !J,,S.fJ.& 3l J;:~e3dla-.,....,.,. -3() -Oapll> 10 gmurd _, In feat Plate 1,2 Hlstor!cally Highest Ground W/!der Contours and 13orehole Log Data Locations, Newpol1 Beach Quadrangle, PA2021-012 E .c ......, C. a, Q 0 5 10 15 20 Stress Reduction Coefficient, rd 0.2 0.4 0.6 0.8 Average valu~s by Seed & Idriss (1971) Approximate average values from Eq. 2 Range for different soil profiles by Seed & Idriss (1971) 1.0 FIG. 1. rd versus Depth Curves Developed by Seed and Idriss (1971) with Added Mean-Value Lines Plotted from Eq. (2) PA2021-012 TABLE 2. Corrections to SPT (Modified from Skempton 1986) as Listed by Robertson and Wride (1998) · Factor Equipment variable Term Correction (1) (2) (3) (4) Overburden pressure -C.v (Palcr ~)9·5 Overburden pressure -C.v CN < 1.7 Energy ratio Donut hammer CE 0.5-1.0 Energy ratio Safety hammer CE 0.7-1.2 Energy ratio Automatic-trip Donut-CE 0.8-1.3 type hammer Borehole diameter 65-115 mm Cs 1.0 Borehole diameter 150 mm Ca 1.05 Borehole diameter 200mm CB 1.15 Rod length <3 m CR 0.75 Rod length 3-4 m CR 0.8 Rod length 4-6 m CR 0.85 Rod length 6-10 m CR 0.95 Rod length 10-30 m CR 1.0 Sampling method Standard sampler Cs 1.0 Sampling method Sampler without liners Cs 1.1-1.3 PA2021-012 ,._ 0 0.6 -----..-----=.,,-..------..-----,-------, "'37 Percent Fines = 35 15 2:.5 : I 0.5 -------------: ---'-1+------------1 I I I I I I I I I I I I 1 I I I I r I I I 0.4 1------+-------1-r,-,...,..---+-----+---------i I , I , I I I I SPT Clean Sand Base Curve 0.3 t------20--+-----+----.-'---+-------1--------r .,2 / I I , ,,p • ••o '.50+ 60 10• • 0.21---.:.;;50--:;JJJ..-f:::it'1-!~:----r--l::~'-----t------+------t 10 30 !t\:J • 22. 1s• FINES CONTENT~ 5% Modified Chinese Code Proposal (clay content,. 5%)@ ~ . N Marginal o -. 1 Adjustment Recommended By Workshop 10 Pan -America data Japanese data Chinese data 20 liquefaction Liquefaction Liquefaclio n ■ Ill • "' 30 40 El A. Corrected Blow Count, (N1)60 50 FIG. 2. SPT Clean-Sand Base Curve for Magnitude 7 .5 Earth- quakes with Data from Liquefaction Case Histories (Modified from Seed et al. 1985) PA2021-012 4.5 ~ 4 Cl'l :E 3.5 ..: 0 3 .... u fl: 2.5 00 c:: ·--2 d u en 0 1.5 "O :::s ..... .... 1 C: OJ) ca :; 0.5 0 -+-Seed and Idriss. ( 1982) -+------'.---__,,....;-----..._-of recomme -11-Idriss -1----...-------->,,~"-='-F;.....;.;;.fro.;;;..::m~N;.;;;;C=EE=.;:;.-1 x Ambraseys ( 1985) 5.0 6.0 Workshop . ◊ Arango (1996) 7.0 ♦ Arango ( 1996) ----Andrus and S tokoe A Youd and Noble, PL<20% A Youd and Noble, PL<32% A Youd and Noble, PL<50% 8.0 9.0 Earthquake Magnitude, Mw FIG. 12. Magnitude Scaling Factors Derived by Various Inves- tigators (Reproduced from Youd .and Noble 1997a) PA2021-012 APPENDIXC Calculations of Seismically Induced Settlement Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California COAST GEOTECHNICAL, INC. PA2021-012 CALCULATIONS OF SEISMICALLY-INDUCED SETTLEMENT Calculations of seismically-induced settlement for the subject site are performed based on the II Evaluation Of Settlement In Sands Due To Earthquake Shaking II by Kohji Tokimatsu and H. Bolton Seed, dated August 1987. The calculations of the seismically-induced settlement are as follows: 1. Calculate the effective overburden pressure at the center of each layer. 2. The SPT N-value needs to be corrected depending on equipment used and a0'. (N1)ao = Nm CN CE Cs CR Cs Where CN = (Pa/ a0') 112 < 2, Pa= 2089 psf (N1)ao = corrected N value Nm = field N value CN = correction factor depending on effective overburden pressure a0' = effective overburden pressure, in psf 3. Calculate the maximum shear modulus Gmax = 20 (N1)60 113 ( a0' ) 112 Gmax = maximum shear modulus, in ksf a0' = effective overburden pressure, in psf 4. From the depth in Figure 1, find the stress reduction coefficient, rd 5. Calculate Yetr ( Geff I Gmax) Yetr ( Getr I Gmax) = 0.65 amax ao rd I ( g Gmax) amax = 0.727 g and M = 7.2 ( for the subject site) Yeff = effective shear strain induced by earthquake shaking Geff = effective shear modulus at induced strain level (cont'd) Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate N1 COAST GEOTECHNICAL, INC. PA2021-012 CALCULATIONS OF SEISMICALLY-INDUCED SETTLEMENT amax = maximum ground surface acceleration a0 = total overburden pressure g = acceleration of gravity 6. From Yeff ( Gett I Gmax) and a0' in Figure 2, find Yett (cyclic shear strain) 7. From Yett and (N1)60 in Figure 3, find cc.M. = 7_5 (volumetric strain due to compaction) 8. Interpolation from Table 1, cc.M. = 1.2 = 0.940 cc.M. = 1.5 9. This settlement caused by combined horizontal motions is about equal to the sum of the settlement caused by the components acting alone. Calculate 2 s c.M. = 1.2 10. Calculate the total settlement Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California Work Order 600320 Plate N2 COAST GEOTECHNICAL, INC. PA2021-012 SEISMICALLY INDUCED SETTLEMENT OF DRY SAND FOR BORING NO. 1 ::: :::r~,; ;~;; :, •.. ~~:i,,i:!~:i:i i:i~:i: ::::~m;g; ;;:~t~;;:; :::•:~•;;; ii:i:~::::• ·~~~~;~ ;;;::i:iu~:;;:;;;; ;:~ii;:: :::ii:;;; i:~~~~~i: :i0:i: 1 2.0 4.0 3.0 2.0 315 315 18 28.9 1089 0.99 13.5 *10-5 41 *10-5 0.031 0.029 0.058 0.01 2 4.0 6.0 5.0 I 2.0 I 525 I 525 I 12 I 19.3 I 1229 I 0.99 I 20.0 *10-5 I 53 *10-5 I 0.060 I 0.056 I 0.113 0.03 Based on : 1. Moist unit weight of 105 pcf, saturated unit weight of 120 pcf, and groundwater at 6 feet 2. Magnitude of 7.2 and peak ground acceleration of 0.727 g 3 G = 20 (N ) 1/3 ( O'. I ) 1/2 • max 1 60 O 4. Yeff ( Geff I Gmax ) = 0.65 amax <lo rd / ( g Gmax) Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California COAST GEOTECHNICAL, INC. TOTAL 0.04 Work Order 600320 Plate No. N3 PA2021-012 103 --., >,. C ·-0 ,._ V) ,._ 0 4,) .c V) -4 10 -~ 10 ~ _ ___. _ _..__.___._ ..................... _________ ....._ ................ _,_ __ _,___, ,o-s ,o-4 Yeff {Get f /Gmax) FIG. ·2 -PLOT FOR DETERMINATION OF INDUCED STRAIN IN SAND DEPOSITS PA2021-012 Cyclic Shear Strain, r... -percent lo_"J. -2 x.y I .,,) 10 10· ,o·3 .---,--.--.--,----.---r--.-.--r----r-----.--......---__: u w C: 0 u 0 0. E 10 1 0 u 0 - ~ :l 0 C: ·-0 ... - ::::5 ' ' ,. ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '\. ' ' ' ' ' ' ' ' ' ' ' '\ IS Cycles ' '\ ' ' ' ' ' ' ' ' ' "\ ' ' ' ' ' ' ' ' .... --~ 10 ~-..,.__._,_._,...i,_ _ _,L,. _ __,.J~..L-~--..__-....L..__.__._,L.._.....J FIG. 3 -RELATIONSHIP BETWEEN VOLUMETRIC STRAIN, SHEAR STRAIN, AND PENETRATION RESISTANCE FOR DRY SANDS PA2021-012 TABLE 1 -INFLUENCE OF EARTHQUAKE MAGNITUDE ON VOLUMETRIC STRAIN RATIO FOR DRY SANDS Earthquake magnitude ( 1) 8-1/2 7-1/2 6-3/4 6 5-1/4 Number of representative cycles at 0.65 -r max (2) 26 15 10 5 2-3 Volumetric strain ratio, Ec.N / Ec,-N-1s (3) 1.25 1.0 0.85 0.6 0.4 PA2021-012 SEISMICALLY INDUCED SETTLEMENT OF SATURATED SOILS FOR BORING NO. 1 8Nit~l l! ~~~ i rl[~j) 111~:~rf~ ~~j:i!J'> ""'ll■:1111111~.!llil!llllll ~111111 6.0 8.0 2.0 I 30.5 5 o.oo I 1.00 30.5 0.51 2 8.0 10.0 2.0 I 37.8 7 0.12 I 1.01 38.2 0.57 3 10.0 12.0 2.0 I 30.9 9 0.56 I 1.02 32.0 0.62 Note: 1. Groundwater at 6 feet, magnitude of 7.2, and peak ground acceleration of 0.727 g 2. (N1 )50 cs = a + fJ (N1)60 3. For volumetric strain refer to Figure 7.11 Geotechnical Engineering Investigation 508 Via Lido Nord Newport Beach, California COAST GEOTECHNICAL MSF dsRts. ~t;~~~~j~ 1 H ~miti~~~~tiili 1.15 0.44 0.6 0.14 1.15 0.50 0.0 0.00 1.15 0.54 0.5 0.12 TOTAL 0.26 Work Order 600320 Plate No. 0 PA2021-012 Influence ~f Fines Content In the original development, Seed et al. (1985) noted an apparent . increase of CRR with increased fines content. Whether this increase is caus~d by an increase of liquefaction resistance or a decrease of penetration resistance is not clear. Based on the empirical data available, Seed et al. developed CRR curves for various fines contents reproduced in Fig. 2. A revised correction for fines content was developed by work- shop attendees to better fit the empirical database and to better support computations with spreadsheets and other electronic computational aids. The workshop participants recommend (5) and (6) as ap- proximate corrections for the influence of fines content (FC) on CRR. Other grain characteristics, such as soil plasticity, may affect liquefaction resistance as well as fines content, but widely accepted corrections for these factors have not been developed. Hence corrections based solely on fines content should be used with engineering judgment and caution. The following equations were developed by I. M. Idriss with the assistance of R. B. Seed for correction of (N1)60 to an equiv- alent clean sand value, (N1)6ocs: (5) where a and ~ = coefficients determineq from the following relationships: · a = 0 for FC < 5% (6a) a= exp[l.76 -(190/FC2)] for 5% < FC < 35% (6b) a = 5.0 . for FC :2:: 35% (6c) j3 = 1.0 for FC ~ 5% (7a) j3 = [0.99 + (FC 15/1,000)] for 5% < FC < 35% (7b) f3 = 1.2 for FC > 35% (7c) These equations may be used for routine liquefaction resis- tance calculations. A back-calculated curve for a fines content of 35% is essentially congruent with the 35% curve plotted in Fig. 2. The back-calculated curve for a fines contents of 15% plots to the right of the original 15% curve. PA2021-012 Recommended Procedures for Implementation of DMG Special Publication 117 Guidelines for Analyzing and Mitigating liquefaction Hazards in California 0.6,r------,-----,-----.-----,---- Volumetric Strain-% 0.5 10 5 4 3 2 0.5 I I 0.4 0.3 0.2 0.1 I I I I I ) /,0.2 I I I I I I ; // p.l I I / / I I I I I·/ I I I I I I I I I 'I I I I I I I I I I / I I I I I I / / / / I / / / ./ I' / .,/ // /,, // ,, / '/,, '// ,.,,,, '// 1// 1/ 10 20 30 40 50 Figure 7.11. Relationship Between Cyclic Stress Ratio, (N1)60 and Volumetric Strain for Saturated Clean Sands and Magnitude= 7.5 (After Tokimatsu and Seed, 1987) 60 PA2021-012 8/6/2020 U.S. Seismic Design Maps OSHPD 508 Via Lido Nord, Newport Beach, CA 92663, USA Latitude, Longitude: 33.613692, -117.9173254 Date D~~ign.Code Refe~ence Do~ument Risk Category Site Class Type Value Ss 1.385 S1 0.493 SMs 1.662 SM1 null -See Section 11.4.8 Sos 1.108 So1 null -See Section 11.4.8 Type Value soc null -See Section 11.4.8 Fa 1.2 Fv null -See Section 11.4.8 PGA 0.606 FPGA 1.2 PGAM 0.727 TL 8 SsRT 1.385 SsUH 1.528 SsD 2.613 S1RT 0.493 S1UH 0.536 S1D 0.825 PGAd 1.055 CRs 0.906 ! CR1 0.919 ' https://seismicmaps.org Description 8/6/2020, 2:23:48 PM ASCE7-16. II D -Default (See Section 11.4.3) MCER ground motion. (for 0.2 second period) Description MCER ground motion. (for 1.0s period) Site-modified spectral acceleration value Site-modified spectral acceleration value Numeric seismic design value at 0.2 second SA . Numeric seismic design value at 1.0 second SA Seismic design category Site amplification factor at 0.2 second Site amplification factor at 1.0 second MCE~· p;~k gr~und ;~~l;;r~tion Site amplification factor at PGA Site modified peak ground acceleration : Long-period transition period in seconds Probabilistic ri;k-targeted gfo~~d ~~ti~":-. (0~ second) Factored uniform-hazard (2% probability of exceedance in 50 years) spectral acceleration ta~tdr;;;£~;te~mini;tic·;c~;;i;~tion\,ii~J. ·;co:2·s;;cond) .. Probabilistic risk-targeted ground motion. (1.0 second) ·co•. -~ .. ,,, •. ,.,.,_,,.~ ,. . Fa.ctore<i.~.niforn:-hazard (2~ prob,ab,ility of exceedance in 50 years} spectral acceleratio":., Factored deterministic acceleration value. (1.0 second) F.actored deterministic acceleration value. (Peak Ground Acceleration) Mapped value of the risk coefficient at short periods Mapped value of the risk coefficient at a period of 1 s 1/2 PA2021-012 8/6/2020 U.S. Seismic Design Maps DISCLAIMER While the information presented on this website is believed to be correct, SEAOC /OSHPD and its sponsors and contributors assume no responsibility or liability for its accuracy. The material presented in this web application 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. SEAOC / OSHPD do 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 seismic data 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 search results of this website. https://seismicmaps.org 2/2 PA2021-012 SEISMIC FACTORS SM 1 and S0 1 SM1 and S01 Calculations based on ASCE?-16 Site Class = D S1 = 0.493 Long Period Site Coefficient, Fv Site Class S1 <= 0.1 S1 = 0.2 C 1.5 D 2.4 Fv = 1.807 SM1 = Fv S1 = 1.807 * 0.493 = 0.891 = 2/3 * 0.891 = 0.594 1.5 2.2 S1 = 0.3 S1 = 0.4 1.5 1.5 2.0 1.9 S1 = 0.5 S1 => 0.6 1.5 1.4 1.8 1.7 Geotechnical Engineering Investigation 508 Via Lido Nord Work Order 600320 Newport Beach, California Plate X COAST GEOTECHNICAL, INC. PA2021-012