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Home My WebLink About20190607_SOILS 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Phone 949 629 2539 | Email info@rmccarthyconsulting.com January 24, 2019 Mylinda Viola File No: 8283-00 4709 Cortland Drive Report No: 20181106-1 Corona del Mar, California 92625 Subject: Geotechnical Investigation Proposed Retaining Wall Replacement 4709 Cortland Drive Tract 3519, Lot 2 Cameo Highlands Corona del Mar, California APN: 475-065-02 INTRODUCTION This report presents the results of our geotechnical investigation for replacement of the southwest bluff retaining wall at 4709 Cortland Drive in Corona del Mar, Newport Beach, California. The purpose of our review and investigation was to evaluate the subsurface conditions, determine the compatibility of the proposed wall replacement with respect to the geotechnical features of the site, and provide preliminary geotechnical recommendations and design parameters. Project Authorization The work performed was per your authorization based on our Proposal No: 20180918-4, dated September 24, 2018. Scope of Investigation The investigation included the following: 1. Review of collected geologic, geotechnical engineering and seismological reports and maps pertinent to the subject site. A reference list is included in Appendix A. 2. Subsurface exploration consisting of three auger borings to a maximum depth of 13.5 feet and auger borings on the adjoining lot to a depth of 23.5 feet. The locations of the borings are shown on the Geotechnical Plot Plan, Figure 1. 3. Logging and sampling of the exploratory borings, including collection of soil samples for laboratory testing. The Logs of the exploration are included in Appendix B. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 2 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 5. Laboratory testing of soil samples representative of subsurface conditions. The results are presented in Appendix C. 6. Geotechnical engineering and geologic analyses of collected data, including preparation of geotechnical cross-sections, Figures 2 and 3. 7. Preparation of this report containing our geotechnical recommendations for the design and construction in accordance with the 2016 California Building Code (CBC) and for use by your design professionals and contractors. Site Description The subject property is located on the south side of Cortland Drive as shown on the Location Map, Figure 4. The general area is within the Cameo Highlands community of Corona del Mar in the City of Newport Beach, California. The property is flanked to the southeast by a developed lot, and to the northwest by a lot that is under construction. The northeast side of the lot fronts Cortland Drive. A keystone retaining wall is in place along the southwest side of the lot. The wall has a maximum height of about 14.5 feet. The wall parallels Pacific Coast Highway (PCH) and is contiguous with the wall along other lots to the southwest along Cortland. The northwesterly terminus of the wall is at 4709 Cortland where it meets a fill slope in the westerly corner. There is a fairly level shoulder between the base of the wall and the curb for PCH. There are utility easements in the road shoulder. The Topographic Map prepared by Don Barrie & Associates (Reference 1) was used as a base map for our Geotechnical Plot Plan, Figure 1. The existing lot at the top of the wall is at about elevation 160.8 and the base of the wall is approximately 146.5 according to Reference 1. Site History The subject site is designated as Lot 2 of Tract 3519. Previous rough grading of the entire tract, which is thought to have been done in the 1950’s, consisted of cuts and fills to create the current level pads and terraced hillside topography. Lot 2 appears to be a cut and fill lot. The keystone wall is approximately along the location of the former bluff or road cut that parallels PCH. The historic bluff turned to the northeast near the boundary with Lot 1 on the northwest property line. Geologic investigation for 4701 Cortland was reported in References 24-26. Findings indicated that fill was placed against the bluff to form Lot 1 and the westerly corner of Lot 2. The maximum fill thickness is estimated to be approximately 10 to 15 feet below Lot 2. The keystone wall was constructed approximately 25 to 30 years ago on the southwest side of the lots along this segment of Cortland Drive. Based on the references the wall was designated the “Cortland Trust Retaining Wall.” The purpose of the wall was to add stability to the bluff slope along PCH and, in turn, the yards along Cortland Drive. The construction also extended portions of the lots toward PCH along much of the wall. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 3 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 The wall design was addressed by Geobase (1987). It was not determined if the Geobase report was used for design of the existing wall. Based on subsequent references, the wall was to be constructed as a reinforced earth wall with keystone blocks forming the outer face. Petra reported observation and testing during construction of the reinforced earth wall in 1992 and 1993. Problems with the wall were reported in 1994. The problems included deformation of the wall and settlement in localized areas. In some locations it was determined that the geogrid was improperly placed or not placed at all (Petra 1995). A repair of the keystone wall was done at 4709 Cortland in 1998 (Reference 23). The repair consisted of the installation of a grade beam with tieback anchors to improve lateral support along the wall. The grade beam was reportedly installed at about 4 to 6 feet below the top of the wall with eight tiebacks installed at 8 feet on center extending about 12 to 15 feet into the lot. The repair is depicted in excerpts included from Reference 23 in Appendix F and on the Geotechnical Plot Plan, Figure 1. The City of Newport Beach contacted our office on November 27, 2018 to inquire about our investigation for the wall at 4709 Cortland. The city official expressed that the wall was failing and that a remedy was needed. Findings Our site observations indicated that the keystone reinforced wall was distressed and deformed. Bulges were evident along the mid to lower portions of the wall, which are indicative of lateral movement. Cracks were observed in the lot sidewalls that abut the keystone wall. The wall backfill soil was tested and determined to contain plastic clay material. No geogrid reinforcement was encountered in our boring at the back of the wall. Monterey Formation bedrock materials are present below the existing fill material at depths of about 11 to 15 feet. Proposed Development We understand that construction of a new retaining wall is under consideration to replace the existing keystone reinforced earth wall. GEOTECHNICAL CONDITIONS Geologic Setting The property lies within the Peninsular Ranges geomorphic province of southern California. The property is situated at the seaward margin of a broad marine terrace of Quaternary aged marine sediments (Qtm) that occurs along the coastal margin of the San Joaquin Hills. The marine terrace was developed as a wave cut terrace overlying older Monterey Formation (Tm) sedimentary bedrock strata of Miocene age that was uplifted, then cut flat by the onset of an encroaching ocean with resulting marine terrace at the surface. Bedrock assigned to the Monterey Formation was encountered at a depth of 13 feet behind the wall and less than 2 feet in front of the wall below this site. This bedrock formation is also exposed along the sloping PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 4 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 margins of the nearby coastal bluffs to the southwest and Buck Gully to the northwest where past erosion has cut into the terrace deposits and underlying bedrock. Portion of: GEOLOGIC MAP OF THE SAN BERNARDINO AND SANTA ANA 30’ X 60’ QUADRANGLES, CALIFORNIA U. S. Geological Survey, Open File Report 2006-1217 Compiled by Douglas M. Morton and Fred K. Miller, 2006 Earth Materials The site is underlain at depth by bedrock strata of the Monterey Formation of late Miocene age which is successively overlain by terrace deposits and/or artificial fill soil. As observed in the borings and nearby road cuts, the Monterey Formation consists of firm but friable, thinly bedded, light grey/brown/yellow, diatomaceous and siliceous shale with planar bedding surfaces displaying iron and manganese staining and scattered concretionary beds. Terrace deposits in the vicinity generally consist of silty sand, clayey sand and sandy clay. Artificial fill derived from terrace deposits and the Monterey Formation ranged in thickness from about 13 feet at the back of the wall to less than 2 feet at the front of the wall. The existing fill materials consist of red-brown clayey to silty sand and sandy clay. Due to lack of adequate documentation about their placement and consistency, these deposits are not considered PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 5 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 suitable in their present condition for structural support. Much of the existing artificial fill within the cut and backfill zone will be removed by the proposed construction of a new retaining wall. The terrace deposits and artificial fill may be prone to caving in steep-sided excavations and borings; however, caisson boreholes and excavation cuts on Lot 1 were relatively stable. Idealized profiles of the various materials encountered in the exploratory borings are depicted on Figure 2, Geotechnical Cross-Section A-A’. The fill material has a moderate plasticity and is expansive. The majority of the on-site earth materials should excavate readily with conventional moderate to heavy duty grading and excavation equipment. Bedrock will be encountered in shoring excavations for soldier piles and deepened foundations. Bedrock may be difficult to excavate in sandstone or concretion layers. Drilling into the bedrock for soldier piles will, therefore, require appropriate equipment for the very dense/hard bedrock conditions. Most materials derived on- site are not suitable as structural backfill. Imported backfill soil or gravel is recommended. Geologic Hazard The geologic hazards at the site are primarily from shaking due to movement of nearby or distant faults during earthquake events. The site is a previously graded hillside lot with a flat to gently sloping building pad located on older marine terrace sediments and bedrock. There is no adverse geologic structure or active faulting near the site indicative of geologic hazards that would affect the site as further detailed below. Structure The underlying bedrock is not exposed at the site. Our findings indicate that the existing wall has a height of 14.5 feet. Bedrock and associated bedding below the site is favorable to slope stability based on regional mapping. The terrace and artificial fill deposits at the site have no significant geologic structure. Bedding structure in the area shown on regional geology maps indicate that the bedding generally dips at angles of about 26 degrees to the northwest (Morton and Miller, 1981) in the vicinity. Since the bedrock is not present within slope areas, and is covered by artificial fill and/or terrace deposits, there is no known adverse geologic bedding structure that is likely to affect stability at the site. The State of California has mapped several geologic faults trending northwest-southeast in the vicinity of the site. The faults are within the underlying bedrock and are concealed by the overlying Quaternary-age massive terrace deposits. The fault is considered inactive at this time; however, sympathetic movement may occur during significant shaking on one of the nearby active fault traces. Groundwater Perched groundwater may occur at the bedrock contact and was observed along the property line joining Lot 1. Groundwater seepage should be addressed as part of the design or PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 6 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 construction. Proper surface drainage and subdrainage systems should, therefore, be incorporated into the project. The presence of groundwater in deeper caisson borings during construction is possible and may promote caving in caisson excavations. Additionally, subdrains and waterproofing should be included in retaining wall design and construction as a precaution against the development of hydrostatic wall loading and possible wall seepage. Water Infiltration On-site water infiltration is not recommended due to potential for future seepage and perched water. Surface and subsurface drainage should be directed toward approved outlets. Surficial Runoff Proposed development should incorporate engineering and landscape drainage designed to transmit surface and subsurface flow to the storm drain systems via non-erosive pathways. Care should be taken to not allow water to pond or infiltrate soil adjacent to foundation elements and slopes. Existing subdrains for walls or improvements that are not scheduled for abandonment as part of the new construction, if present, should be adequately marked, safeguarded and maintained in good working order through the construction period and beyond. Faulting/Seismic Considerations The major concern relating to geologic faults is ground shaking that affects many properties over a wide area. Direct hazards from faulting are essentially due to surface rupture along fault lines that could occur during an earthquake. Therefore, geologists have mapped fault locations and established a criteria for determining the risks of potential surface rupture based on the likelihood of renewed movement on faults that could be located under a site. Based on criteria established by the California Division of Mines and Geology (CDMG), now referred to as the California Geological Survey (CGS), faults are generally categorized as active, potentially active or inactive (Jennings, 1994). The basic principle of faulting concern is that existing faults could move again, and that faults which have moved more recently are the most likely faults to move again and affect us. As such, faults have been divided into categories based on their age of last movement. Although the likelihood of an earthquake or movement to occur on a given fault significantly decreases with inactivity over geologic time, the potential for such events to occur on any fault cannot be eliminated within the current level of understanding. By definition, faults with no evidence of surface displacement within the last 1.6 million years are considered inactive and generally pose no concern for earthquakes due renewed movement. Potentially active faults are those with the surface displacement within the last 1.6 million years. Further refinement of potentially active faults are sometimes described based on PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 7 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 the age of the last known movement such as late Quaternary (last 700,000 years) implying a greater potential for renewed movement. In fact, most potentially active faults have little likelihood of moving within the time frame of construction life, but the degree of understanding of fault age and activity is sometimes not well understood due to absence of geologic data or surface information, so geologists have acknowledged this doubt by using the term "potentially active." A few faults that were once thought to be potentially active, have later been found to be active based on new findings and mapping. Active faults are those with a surface displacement within the last 11,000 years and, therefore, most likely to move again. The State of California has, additionally, mapped known areas of active faulting as designated Alquist- Priolo (A-P) "Special Studies Zones,” which requires special investigations for fault rupture to limit construction over active faults. A potential seismic source near the site is the San Joaquin Hills Blind Thrust Fault (SJHBT), which is approximately 2 to 8 kilometers beneath the site at its closest point, based on the reported fault structure. The SJHBT is a postulated fault that is suspected to be responsible for uplift of the San Joaquin Hills. This fault is a blind thrust fault that does not intercept the ground surface and, therefore, presents no known potential for ground rupture at the property. The site is not located near an active fault, or within a special studies zone for earthquake fault rupture. Inactive, northwest-trending faulting has been mapped to occur in close proximity to the site. The potential for surface rupture at the site is low. SITE PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 8 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 The closest active fault to the site is the Newport Inglewood fault (north branch) located approximately 2.5 kilometers southwest of the site. As such, the potential for surface rupture at the site is very low, but the site will experience shaking, during earthquake events on nearby or distant faults. Site improvements should take into consideration the seismic design parameters outlined below. Site Classification for Seismic Design Seismic design parameters are provided in a later section of this report and in Appendix E for use by the Structural Engineer. The soil underlying the subject site has been classified in accordance with Chapter 20 of ASCE 7, per Section 1613 of the 2016 CBC. SITE PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 9 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 The results of our on-site field investigation, as well as nearby investigations by us and others, indicate that the site is directly underlain by Class D dense to medium dense artificial fill, terrace deposits and sedimentary bedrock. Most of the artificial fill materials are expected to be removed as part of the proposed basement excavation and remedial grading. We, therefore, recommend using a characterization of this property as a Class D, “Stiff Soil,” Site Classification. Secondary Seismic Hazards Review of the Seismic Hazards Zones Map (CDMG, 1998) for the Newport Beach Quadrangle, 1997/1998 and the City of Newport Beach Seismic Safety Element (2008) indicates the site is not located within a zone of required investigation for earthquake-induced liquefaction or landslide. This finding is in keeping with the results of our study. Other secondary seismic hazards to the site include deep rupture, shallow ground cracking, lurching with lateral movement and settlement. With the absence of active faulting on-site, the potential for deep fault rupture is not present. The potential for shallow ground cracking to occur during an earthquake is a possibility at any site, but does not pose a significant hazard to site development. The potential for seismically-induced lurching and settlement to occur is considered remote for the site. The potential for tsunami inundation at the site elevation is nil at the foundation levels. CONCLUSIONS Based on our findings, the existing retaining wall has experienced excessive deformation. Previous repair attempts have not stopped wall movement and continued movement of the keystone blocks is expected. Future movements could result in catastrophic failure of the wall, which could damage adjoining properties. The existing wall was to be constructed as a reinforced earth wall with keystone block facing to protect the reinforced earth from erosion. The archived records for the site suggest that the geogrid reinforcement was not properly installed and/or designed resulting in the existing deformed wall conditions. Repair of the existing wall is not practically feasible if the geogrid reinforcement behind the wall is missing or inadequate. A new caisson supported wall is therefore recommended for the property. Construction of a caisson supported retaining wall would be expected to include the following: 1. Adjoining properties will need to be protected during demolition and construction. 2. Utilities along the base of the wall will need to be located by the contractor prior to demolition and construction. 3. Shoring should be installed along the southeast property line to stabilize improvements on the adjoining lot. 4. Shoring is not expected to be necessary on the northwest property line due to the topography and the abandoned shoring along the property line from the current development at 4701 Cortland. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 10 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 5. Demolition should include cutting of the wall at the south corner of the lot in a manner that preserves the integrity of the contiguous wall at the property line; removal of the grade beam and anchors; and removal of the keystone wall facing. 6. Following demolition a drilling platform may be cut or filled to allow excavation for the pile/caisson support elements; the existing backfill may be excavated and removed. 7. Wall construction. 8. Drain and backfill installation behind the new wall. RECOMMENDATIONS Structural Design of Retaining Walls 1. Lateral Loads Active pressure forces acting on the backfilled new retaining wall may be computed based on an equivalent fluid pressure of 40 pounds per cubic foot when backfilled with non-expansive sand or gravel per the recommendations below. Other topographic and structural surcharges should be addressed by the structural engineer. 2. Earthquake Loads on Retaining Walls The structural engineer should determine which retaining walls at the site within their purview will be subject to design lateral loads due to earthquake events. Section 1803.5.12 of the 2016 CBC states that the geotechnical investigation shall include the determination of dynamic seismic lateral earth pressures on foundation walls and retaining walls supporting more than 6 feet (1.83 m) of backfill height due to design earthquake ground motions. The proposed new wall retaining a level backfill condition may be considered using an additional dynamic load (∆PaE) of 36 pounds per cubic foot equivalent fluid pressure. This force is presumed to act at 0.33H above the base of the wall (Al Atik and Sitar, ASCE 2010). This value is preliminary and we recommend that each wall be evaluated individually as plans are prepared. Note that the load diagrams and lateral pressures may vary based on wall height, orientation and backfill conditions. We therefore recommend that structural design not proceed until each wall is addressed by the geotechnical engineer based on the planned retaining wall configurations. 3. Foundation Bearing Values for Walls The wall will be caisson supported. Recommendations are provided below. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 11 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 4. Wall Backfill The on-site soils are not considered suitable for use as retaining wall backfill. Imported backfill should consist of select, non-expansive soil or gravel. Gravel may consist of pea gravel or crushed rock. Where space for compaction equipment is adequate, on-site or imported granular, non-expansive sand materials may be compacted into place in thin lifts per the compaction requirements provided herein. Imported pea gravel or crushed rock should be placed in lifts and tamped or vibrated into place. The lift thickness for gravel is dependent on the type of material and method of compaction. Gravel lifts of 18- to 24-inches or less are recommended. Soil lifts should be 6-inches or less. The Geotechnical Engineer should observe the backfill placement of soil or gravel behind each wall following approval of wall backdrains. Gravel wall backfill material should be completely surrounded with a suitable filter fabric such as Mirafi 140N and capped with on-site soil or concrete. Fill and backfill soils should be free of debris, organic matter, cobbles and rock fragments greater than 6-inches in diameter. Fill materials should be placed in 6 to 8- inch maximum lifts at above optimum moisture content and compacted under the observation and testing of the soil engineer. The recommended minimum density for compacted material is 90 percent of the maximum dry density as determined by ASTM D 1557-12. Field density tests should be performed at intervals of 2 vertical feet or less within the backfill zone and in accordance with agency requirements at the time of grading. 5. Subdrains An approved exterior foundation subdrain system should be used to achieve control of seepage forces behind retaining walls. The details of such subdrain systems are deferred to the wall designer, builder or waterproofing consultant. The subdrain is not a substitute for waterproofing. Water in subdrain systems should be collected and delivered to suitable disposal locations or facilities. Additional recommendations may be provided when plans are available. Retaining walls should be provided with an approved drain at the base of the backfill. Subdrains should consist of a 4-inch diameter perforated pipe (Schedule 40 or similar) surrounded by at least 3 cubic feet per foot of ¾-inch gravel wrapped in geofabric (Mirafi 140N or similar). Perforations should be placed down and filter fabric should be lapped at least 12-inches at seams. 6. Dampproofing and Waterproofing Waterproofing should be installed in accordance with the architectural specifications or those of a waterproofing consultant. A Miradrain type system is recommended for the height of the basement wall backfills. Waterproof systems and materials should be installed in accordance with manufacturer’s recommendations, based on geologic PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 12 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 conditions. The criteria in Section 1805 of the 2016 CBC should be followed as a minimum. Piles/Caissons Piles should have a minimum length of 30 feet below the grades along the base of the retaining wall and should extend through fill or terrace deposits and into competent, undisturbed, and geotechnically approved bedrock materials. Actual depths will be determined in the field during drilling. Cast-in-Drilled Hole (CIDH) Piles may be designed for a dead plus live load end bearing value of 9,000 pounds per square foot for the minimum embedment depth into the terrace deposits. A skin friction value of 300 pounds per square foot at depths below 5 feet (or the depth of any adjacent utility line backfill or trench, whichever is deeper) may also be utilized. Lateral resistance may be calculated utilizing 300 pounds per cubic foot equivalent fluid pressure, acting on a tributary area of twice the CIDH Pile diameter, with a maximum lateral value of 6,000 pounds per square foot. No lateral resistance should be utilized in the upper 5 feet. Pile/Caisson Construction Considerations CIDH pile excavations should be filled with concrete on the same day they are drilled unless adequately covered and subsequently checked for caving and slough at the bottom of the shaft immediately prior to pouring concrete. Sequencing of the drilling may be required where piles are spaced less than 8 feet center to center. It is essential that the geotechnical engineer/geologist be present to observe all CIDH pile excavations, as they are drilled, to determine soil and bedrock horizons and to verify that the excavation depths are in conformance with the design criteria. Shaft casing, if utilized, should be installed under full-time observation of the geotechnical engineer/ geologist. CIDH piles should have a minimum embedment into competent material in accordance with the recommendations herein and the structural engineer’s foundation plans. Excavations should be visually observed after completion to determine that disturbed materials and/or water are not present at the base. Safety requirements demand that where hand-cleaning and/or “down-shaft” inspection personnel are required, the shaft must be cased full-length prior to personnel entering the shaft. Other safety requirements, including Cal-OSHA, should be adhered to as appropriate. Prior to pouring concrete, bottoms of the shafts should be cleaned of disturbed materials, if present. The project specifications should indicate that the contractor is responsible for removing any disturbed material from the bottom of the shaft. Water is not anticipated in excavations, although could be present as a localized perched condition in some shafts. If present, water should be removed. Caving of fill and terrace deposit materials is possible within excavations. The potential for caving increases the longer the excavations are left open, as the pile diameter increases, and PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 13 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 with the presence of perched water zones that result in seepage into the shaft. Caving problems may be reduced by the use of casing and prompt placement of concrete. Shoring Excavations for proposed retaining wall at the site will necessitate the use of shoring since slope laybacks steeper than 1:1 from the property line to the bottom of the overexcavation are necessary. Selection of an appropriate shoring system should consider the potential effects of vibrations, deflections and lateral support of adjoining properties. The current City of Newport Beach policy requires that temporary shoring along property lines be designed for At-Rest (Not free to rotate) lateral earth pressures. This aspect of the design is left to the structural engineer. We anticipate that soldier pile and lagging systems will be used for shoring. Design lateral loading values for a cantilevered shoring system should be based upon an equivalent fluid pressure of 72 pounds per cubic foot at-rest pressure for level backfill conditions. Recommended lateral passive resistance for soldier piles founded in dense bedrock is 300 pounds per cubic foot, acting on a tributary area of twice the pile diameter. The passive pressure should not exceed 6,000 psf. Passive resistance may start at the bedrock excavation level along the below grade segment of pile (24-inch diameter). Piles may use an allowable bearing value of 9,000 pounds per square foot for a minimum 10 foot embedment depth into bedrock. A friction angle, phi, of 30 degrees may be used for temporary shoring design for that portion of the pile that extends into bedrock. We anticipate that shoring will be primarily within undocumented fill material. Some terrace deposit materials are also possible between the fill and bedrock. It is the contractor’s responsibility to develop appropriate means and methods of construction to avoid damage to adjacent properties. Proper installation of shoring is the responsibility of the contractor. The adjacent property owners should be notified and advised of the risks and the owner and builder should provide arrangements to repair possible damages. Existing soil conditions behind shoring elements may result in collapse and caving of soils during removal of shoring. Permanent shoring is therefore recommended unless the contractor can demonstrate a safe system for removal of shoring elements. All soldier pile installations should be observed by the geotechnical consultant to verify that the intent of the recommendations herein are implemented. After the soldier piles have been placed and backfilled, site excavations may begin. Sufficient curing time for concrete and grout should be allowed before excavating. Care should be taken to make sure that the lagging drops into place as the excavations advance. Gaps in the lagging or behind the lagging are undesirable and could cause undermining of adjacent soils and should be immediately filled with grout or slurry. Prior to drilling and installing the shoring system, the shoring plans and calculations should be forwarded to the project geotechnical consultant for review to confirm that the shoring has been designed in accordance with the recommendations herein. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 14 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 The placement of shoring should consider that onsite soils may have local variably loose or fractured zones that may be prone to caving and or settlement. Vibratory techniques for placement of piles or steel sheet lagging should not be utilized, as damage to adjoining property improvements may otherwise occur. It is the contractor’s responsibility to develop appropriate means and methods of construction to avoid damage to adjacent properties. Casing of pile excavations is at times necessary in granular materials such as terrace deposits as well as in fractured bedrock materials. If temporary shoring elements are to be utilized, the builder and owner must be aware that removal could result in settlement and possible damage to improvements on the adjacent property. The adjacent property owners must be advised of the risks and the builders should provide arrangements to repair any possible damages. The contractor should also recognize the risk of leaving voids during removal of shoring elements. Lagging, plates and piles should therefore be removed slowly and the voids created should by filled immediately. Consideration should be given to continuously inject grout at the base of piles and plates as they are being removed to fill the resultant voids. Site Preparation and Grading 1. General Site grading should be performed in accordance with the requirements of the City of Newport Beach, the recommendations of this report, and the Standard Grading Guidelines of Appendix D. All excavations should be supervised and approved in writing by a representative of this firm. Remedial grading is recommended to include excavation and disposal of the existing wall elements, backfill and improvements in the construction zone. 2. Demolition and Clearing Deleterious materials, including those from the demolition, vegetation, organic matter and trash, should be removed and disposed of off-site. Subsurface elements of demolished structures should be completely removed, including any trench backfills, basements, foundations, anchors, septic tanks, cisterns, abandoned utility lines, etc. 3. Site Excavation Temporary shoring should be installed as necessary to accomplish the wall and soil removals while protecting adjacent properties. The older fills on the pad area of the lot should be removed to competent native terrace deposits within the wall backfill zone, which should consist of a 1:1 projection from the base of the wall back. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 15 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Site profiles and geologic units are depicted in Cross-Sections A-A’, Figure 2. The depicted profile is based on exploratory boring data and are idealized cross-sections through the site. Actual removals will need to be verified and adjusted as necessary in the field during grading as conditions are exposed. Excavations that require filling should be replaced with compacted engineered fill. Removals of unsuitable soils should extend property line to property line along the side yards below building areas in order to eliminate the existing fills that are present below the site. The depths of overexcavation should be reviewed by the Geotechnical Engineer or Geologist during the actual construction. Any surface or subsurface obstructions, or questionable material encountered during grading, should be brought immediately to the attention of the Geotechnical Engineer for recommendations. 4. Construction Dewatering Perched water and seepage zones are familiar conditions within the Cameo Highlands area. The Contractor should anticipate these conditions and have a plan in place prior to shoring and excavation to deal with seepage. Casing may be required in shoring elements. Temporary drains and stops may be necessary during lagging installation and a diversion drain system is recommended to keep nuisance water out of the work areas. Subgrade stabilization may also be necessary if basement grade soils are saturated. 5. Fill Soils The on-site soils are not suitable for use as retaining wall backfill but may be used as compacted fill outside of the backfill zones. Fill soils should be free of debris, organic matter, cobbles and concrete fragments greater than 6-inches in diameter. Soils imported to the site for use as fill and backfill should be predominantly granular, non-expansive, non-plastic and approved by the Geotechnical Engineer prior to importing. 8. Compaction Standard Fill materials should be placed at near optimum moisture content and compacted under the observation and testing of the Soil Engineer. The recommended minimum density for compacted material is 90 percent of the maximum density as determined by ASTM D1557-12. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 16 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 9. Temporary Construction Slopes Temporary slopes exposing onsite materials should be cut in accordance with Cal/OSHA Regulations. It is anticipated that the exposed onsite earth materials may be classified as Type B soil overlying Stable Rock. Temporary cuts of 1:1 (horizontal: vertical) above the bedrock are expected be appropriate. Temporary excavation cuts should be a 1:1 or flatter plane extending downward from the property line unless shoring is present or installed. The material exposed in temporary excavations should be evaluated by the contractor and geotechnical consultant during excavation and construction. Trenches away from property lines may be cut vertical to a maximum depth of 4 feet. Shoring should be anticipated where space limitations preclude temporary slope layback and should be anticipated for portions of retaining wall constructed along the southeast side property margins where vertical height exceeds 5 feet in the fill materials. Lateral support of adjacent public and private property improvements should be maintained during grading and construction. The use of lagging or plates between shoring elements will be required for excavations. Excavations should be reviewed by the Geologist as these materials are exposed. The safety and stability of temporary construction slopes and cuts is deferred to the general contractor, who should implement the safety practices as defined in Section 1541, Subchapter 4, of Cal/OSHA T8 Regulations (2006). The geotechnical consultant makes no warranties as to the stability of temporary cuts. Soil conditions may vary locally and the contractor(s) should be prepared to remedy local instability if necessary. Contract documents should be written in a manner that places the Contractor in the position of responsibility for the stability of all temporary excavations. Stability of excavations is also time dependent. Unsupported cuts should not be allowed to dry out and should not be left open for extended time periods. 11. Adjacent Property Assessments and Monitoring The proposed excavations into hard or dense terrace deposits and bedrock materials will cause vibrations and sound pressure (noise) that may be potentially disturbing to occupants of neighboring properties. If appropriate equipment and experienced operators and contractors perform the excavations, it is unlikely that such vibrations will be sufficient to promote structural damage in the vicinity. The following measures may be considered in order to reduce the potential risks of damage, and perceived damage, to adjoining improvements: • Visual inspections and walk-throughs of each of the adjacent properties should be arranged in order to document pre-existing conditions and damages. • Measurements of all existing damages observed, including crack lengths, widths and precise locations should be made. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 17 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 • Photographs should be taken to accompany written notes that refer to damages or even lack of damages. Video may also be considered; however, videos that attempt to show these types of damages are often lacking in detail. • Floor level surveys of nearby structures may be considered especially if pre- existing damage is evident. • Vibrations from construction equipment may be monitored with portable seismographs during excavation into bedrock materials. Vibration monitoring is, therefore, highly recommended during demolition and installation of shoring. • Surveys to monitor lateral and vertical position of adjacent improvements and shoring elements is recommended. • It is recommended that the Project Geologist be on-site during excavation in order to evaluate conditions as the project advances. Construction activities, particularly excavation equipment, produce vibrations that can be felt by occupants of adjoining properties. People will often be annoyed by the noise and vibration caused by construction activities, which prompts them to personally perform detailed inspections of their property for damage. Pre-existing damage, that previously went unnoticed, can be unfairly attributed to current construction activities, particularly when pre-construction property inspections are not performed. At that point, it may be difficult to determine what caused the damage, especially damages such as wall separations, cracks in drywall, stucco and masonry. Other common problems that may be scrutinized can include uneven doors, sticking windows, tile cracks, leaning patio posts, fences, gates, etc. Implementation of measures such as those listed above can help avoid conflicts by monitoring construction activities that may be problematic as well as provide valuable data to defend against unwarranted claims. Swimming Pools, Spas and Decks Caisson support of swimming pools and spa improvements is recommended. Plans should be forwarded to our office for review for any such improvements between the house and the planned retaining wall. Hardscape Design and Construction Hardscape and landscape plans should be forwarded to our office for review, comment and approval during the design phase and prior to construction. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 18 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Seismic Design Based on the geotechnical data and site parameters, the following is provided by the USGS (ASCE 7, 2010 – with March 2013 errata) to satisfy the 2016 CBC design criteria: Table 2, Site and Seismic Design Criteria For 2016 CBC Design Parameters Recommended Values Site Class D (Stiff Soil) Site Longitude (degrees) -117.8582 W Site Latitude (degrees) 33.5896 N Ss (g) 1.677 g S1 (g) 0.611 g SMs (g) 1.677 g SM1 (g) 0.917g SDs (g) 1.118 g SD1 (g) 0.611 g Fa 1.0 Fv 1.5 Seismic Design Category D Supporting documentation is also included in a previous section of this report, Site Classification for Seismic Design, and in Appendix E. Concrete Construction Components in Contact with Soil The onsite soils and bedrock may have a high soluble sulfate content and moderate to severe soluble chloride levels. Type V cement is therefore anticipated to be suitable for concrete in contact with the subgrade soils. A minimum design strength of 4,000 psi and water to cement ratio of 0.5 maximum should be used for sulfate considerations. It is recommended that a concrete expert be retained to design an appropriate concrete mix to address the structural requirements. In lieu of retaining a concrete expert, it is recommended that the 2016 CBC, Section 1904 and 1905, be utilized which refers to ACI 318. Metal Construction Components in Contact with Soil Metal rebar encased in concrete, iron pipes, copper pipes, etc., that are in contact with soil or water that permeates the soil should be protected from corrosion that may result from salts contained in the soil. Recommendations to mitigate damage due to corrosive soils, if needed, should be provided by a qualified Corrosion Specialist. Additional testing should be done during grading to confirm preliminary test results. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 19 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Surface and Subsurface Drainage 1. Finished Grade and Surface Drainage Finished grades should be designed and constructed so that no water ponds in the vicinity of footings, subterranean walls or slopes. Drainage design in accordance with the 2016 CBC, Section 1804.4, is recommended or per local City requirements. Drainage should be provided and outflow directed away from structures in a non-erosive manner as specified by the Project Civil Engineer or Landscape Architect. Surface and subsurface water should be directed away from slope and retaining wall areas. Proper interception and disposal of on-site surface discharge is presumed to be a matter of civil engineering or landscape architectural design. 2. Drainage and Drainage Devices The performance of the planned foundation and improvements is dependent upon maintaining adequate surface drainage both during and after construction. The ground surface around foundations and improvements should be graded so that surface water will not collect and pond. The impact of heavy irrigation can artificially create perched water conditions. This may result in seepage or shallow groundwater conditions where previously none existed. Attention to surface drainage and controlled irrigation will significantly reduce the potential for future problems related to water infiltration. Irrigation should be well controlled and minimized. Seasonal adjustments should be made to prevent excessive watering. Sources of uncontrolled water, such as leaky water pipes or drains, should be repaired if identified. The Owner should be aware of the potential problems that could develop when drainage is altered through construction of swimming pools, retaining walls, paved walkways, utility installations or other various improvements. Ponded water, incorrect drainage, leaky irrigation systems, overwatering or other conditions that could lead to unwanted groundwater infiltration must be avoided. Area drains should be installed in all planter and landscape areas. Planter surfaces should be sloped away from slope and retaining wall areas in accordance with Code requirements. 3. Infiltration It is strongly recommended that surface water be collected and directed to a suitable off- site outlet rather than allowed to infiltrate into the soil. It is important to not purposely PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 20 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 introduce site water into the gravel zones along retaining walls or into slope areas. Cleaner sand zones within subsurface soils may create pockets for collection of perched water that can back up along retaining walls or travel distances to outlet at lower elevation on slopes. This may result in unwanted water infiltration around structures, nuisance water and potential instability. Utility Trench Backfill Utility trench backfill should be placed in accordance with Appendix D, Standard Grading Guidelines. It is the Owner’s and Contractor’s responsibility to inform Subcontractors of these requirements and to notify R McCarthy Consulting, Inc. when backfill placement is to begin. It has been our experience that trench backfill requirements are rigorously enforced by the City of Newport Beach. The on-site soils are anticipated to be generally suitable for use as trench backfill outside of wall backfill zones; however, fine-grained silt or clay materials may be difficult to mix and compact to a uniform condition. The use of imported backfill is sometimes more efficient when on-site soil materials are at high moisture contents. Fill materials should be placed at near optimum moisture content and compacted under the observation and testing of the Soil Engineer. The minimum dry density required for compacted backfill material is 90 percent of the maximum dry density as determined by ASTM D1557-12. Foundation Plan Review The undersigned should review final foundation plans and specifications prior to their submission to the building official for issuance of permits. The review is to be performed only for the limited purpose of checking for conformance with design concepts and the information provided herein. Review shall not include evaluation of the accuracy or completeness of details, such as quantities, dimensions, weights or gauges, fabrication processes, construction means or methods, coordination of the work with other trades or construction safety precautions, all of which are the sole responsibility of the Contractor. R McCarthy Consulting, Inc.’s review shall be conducted with reasonable promptness while allowing sufficient time in our judgment to permit adequate review. Review of a specific item shall not indicate that R McCarthy Consulting, Inc. has reviewed the entire system of which the item is a component. R McCarthy Consulting, Inc. shall not be responsible for any deviation from the Construction Documents not brought to our attention in writing by the Contractor. R McCarthy Consulting, Inc. shall not be required to review partial submissions or those for which submissions of correlated items have not been received. Pre-Grade Meeting A pre-job conference should be held with representative of the Owner, Contractor, Architect, Civil Engineer, Geotechnical Engineer, and Building Official prior to commencement of PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 21 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 construction to clarify any questions relating to the intent of these recommendations or additional recommendations. Observation and Testing General Geotechnical observation and testing during construction is required to verify proper removal of unsuitable materials, check that foundation excavations are clean and founded in competent material, to test for proper moisture content and proper degree of compaction of fill, to test and observe placement of wall and trench backfill materials, and to confirm design assumptions. It is noted that the CBC requires continuous verification and testing during placement of fill, pile driving, and pier/caisson drilling. An R McCarthy Consulting, Inc. representative shall observe the site at intervals appropriate to the phase of construction, as notified by the Contractor, in order to observe the work completed by the Contractor. Such visits and observation are not intended to be an exhaustive check or a detailed inspection of the Contractor’s work but rather are to allow R McCarthy Consulting, Inc., as an experienced professional, to become generally familiar with the work in progress and to determine, in general, if the grading and construction is in accordance with the recommendations of this report. R McCarthy Consulting, Inc. shall not supervise, direct, or control the Contractor’s work. R McCarthy Consulting, Inc. shall have no responsibility for the construction means, methods, techniques, sequences, or procedures selected by the Contractor, the Contractor’s safety precautions or programs in connection with the work. These rights and responsibilities are solely those of the Contractor. R McCarthy Consulting, Inc. shall not be responsible for any acts or omission of any entity performing any portion of the work, including the Contractor, Subcontractor, or any agents or employees of any of them. R McCarthy Consulting, Inc. does not guarantee the performance of any other parties on the project site, including the Contractor, and shall not be responsible for the Contractor’s failure to perform its work in accordance with the Contractor documents or any applicable law, codes, rules or regulations. Construction-phase observations are beyond the scope of this investigation and budget and are conducted on a time and material basis. The responsibility for timely notification of the start of construction and ongoing geotechnically involved phases of construction is that of the Owner and his Contractor. We request at least 48 hours’ notice when such services are required. PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 22 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 List of Guidelines The Geotechnical Consultant should be notified to observe and test the following activities during grading and construction: • To observe proper removal of unsuitable materials; • to observe the bottom of removals for all excavations for grading, trenching, swimming pool, spa, exterior site improvements, etc.; • to observe side cut excavations for shoring, retaining walls, swimming pool, spa, trenches, etc.; • to test for proper moisture content and proper degree of compaction of fill; • during CIDH Pile/Caisson drilling, if used for shoring and/or deepened foundation support; • to check that foundation excavations are clean and founded in competent material; • to check retaining wall subdrain installation when the pipe is exposed and before it is covered by the gravel and fabric; and again after the gravel and fabric have been placed; • to test and observe placement of wall backfill materials; • to test and observe placement of trench backfill materials; • to test and observe patio, pool deck and sidewalk subgrade materials; • to observe any other fills or backfills that may be constructed at the site. It is noted that this list should be used as a guideline. Additional observations and testing may be required per local agency and Code requirements at the time of the actual construction. The 2016 CBC requires continuous verification and testing during placement of fill materials and during pile/caisson drilling. LIMITATIONS This investigation has been conducted in accordance with generally accepted practice in the engineering geologic and soils engineering field. No further warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. Conclusions and recommendations presented are based on subsurface conditions encountered and are not meant to imply that we have control over the natural site conditions. The samples taken and used for testing, the observations made and the field testing performed are believed representative of the general project area; however, soil and geologic conditions can vary significantly between tested or observed locations. Site geotechnical conditions may change with time due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur as a result of the broadening of knowledge, new legislation, or agency requirements. The recommendations presented herein are, therefore, arbitrarily set as valid for one year from the report date. The recommendations are also specific to the current proposed development. Changes in proposed land use or development may require supplemental investigation or PA2019-107 January 24, 2019 File No: 8238-00 Report No: 20181106-1 Page: 23 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 recommendations. Also, independent use of this report without appropriate geotechnical consultation is not approved or recommended. Thank you for this opportunity to be of service. If you have any questions, please contact this office. Respectfully submitted, R MCCARTHY CONSULTING, INC. Robert J. McCarthy Principal Engineer, G.E. 2490 Registration Expires 3-31-20 Date Signed: 1/24/2019 Distribution: (1) Addressee Accompanying Illustrations and Appendices Text Figure - Geologic Map of the San Bernardino and Santa Ana 30’ x 60’ Quadrangle, California Text Figure - Fault Map, Newport Beach, California Text Figure - CDMG Seismic Hazards Zones, Laguna Beach Quadrangle Map Figure 1 - Geotechnical Plot Plan Figure 2 - Geotechnical Cross-Section A-A’ Figure 3 - Cross Section for Proposed Wall Figure 4 - Location Map Appendix A - References Appendix B - Field Exploration Figures B-1 through B-5 Appendix C - Laboratory Testing Figures C-1 through C-7 Appendix D - Standard Grading Guidelines Appendix E - Seismicity Data PA2019-107 Figure 1: Geotechnical Plot Plan 4709 Cortland Drive Corona Del Mar, CA File: 8283-00 January 2019 0 40 feet N Af/Tm HA-1 Existing Structure HA-2 A A’ Base map: Don Barrie & Associates EXPLANATION Approximate location of exploratory hand auger Af Articial ll Tm Monterey Formation HA-3 Existing tieback anchors (lengths and locations estimated based on references) Existing tie-back grade beam Existing keystone retaining wall P-14 Estimated location of exploratory boring PA2019-107 Raised planter Existing structure Figure 2: Geotechnical Cross-Section A-A’ 4709 Cortland Drive Corona Del Mar, CA File: 8283-00 January 2019 Estimated location of exploratory hand auger Af Articial ll Tm Monterey Formation Contact between geologic units Af Tm Af Tm EXPLANATION PL HA-3 TD 13.5’ HA1 TD 1.5’ Waterline Existing grade beam (approximately 4’ - 6’ below top of wall)ELEVATION, feetN31°E A A’ELEVATION, feet175 165 155 145 135 175 165 155 145 135 0 10 feet IDEALIZED PROFILE Notes: 1. All elevations estimated; gure is idealized. 2. Actual proles may vary signicantly; based on topographic and geologic interpretation. Pacic Coast Highway CL ? ? ? ? ? ? Existing tieback anchors (lengths and locations based on references) Note that utility easements are located at base of wall to be determined by others Existing wall footing dimensions not determined Existing keystone retaining wall PA2019-107 Existing structure Figure 3: Cross-Section for Proposed Wall 4709 Cortland Drive Corona Del Mar, CA File: 8283-00 January 2019 Af Articial ll Tm Monterey Formation Contact between geologic units Af Tm Af Tm EXPLANATION PL WaterlineELEVATION, feetN31°E A A’ELEVATION, feet175 165 155 145 135 175 165 155 145 135 125 115 125 115 0 10 feet IDEALIZED PROFILE Notes: 1.All elevations estimated; figure is idealized. 2.Actual profiles may vary significantly; based on topographic and geologic interpretation. 3.Details for wall design, caissons and grade beam to be designed by structural engineer. 4. Location of new retaining subject to other authorities; presented herein for illustration purposes only (not for construction). Pacic Coast Highway CL ? ? ? ? ? ? New retaining wall - caisson supported New grade beam Caissons for support of new wall Ef New subdrain New engineered wall backfill Various Easements - to be determined by others PA2019-107 Feet Every reasonable effort has been made to assure the accuracy of the data provided, however, The City of Newport Beach and its employees and agents disclaim any and all responsibility from or relating to any results obtained in its use. Disclaimer: 1/22/2019 0 400200 8283-00 JANUARY 2019 LOCATION MAP - FIGURE 4 PA2019-107 R McCarthy Consultants, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 APPENDIX A REFERENCES PA2019-107 APPENDIX A REFERENCES (4709 Cortland Drive) R McCarthy Consulting, Inc 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 1. Don Barrie & Associates, Wall/ESMT Location, scale: 1” = 10’, 3/19/18, Sheet 1 of 1. 2. California Building Code, 2016 Edition. 3. California Division of Mines and Geology, 1998, “Seismic Hazards Zones Map, Newport Beach Quadrangle”. 4. California Divisions of Mines and Geology, 2008, “Guidelines for Evaluating and Mitigating Seismic Hazards in California,” Special Publication 117A. 5. Department of the Navy, 1982, NAVFAC DM-7.1, Soil Mechanics, Design Manual 7.1, Naval Facilities Engineering Command. 6. Gem Designs, Incorporated, 1994, Letter Regarding the Cortland Noise Wall, June 8. 7. Gem Designs, Incorporated, 1994, Letter Expressing Another Viewpoint in Addressing the Situation that Exists at 4839 Cortland Avenue, Lot 13, Tract No. 3519, Corona del Mar, CA, January 14. 8. Geobase, 1987, “Preliminary Geotechnical Investigation, Retaining Wall Along East Side of P.C.H. Immediately South of Cameo Highlands Drive, Newport Beach, California,” File No. R.115.01.00, October 23. 9. Hart, E. W., and Bryant, W. A., 1997, “Fault-Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act: California Division of Mines and Geology,” Special Publication 42 (Interim Supplements and Revisions 1999, 2003, and 2007). 10. Jennings, Charles W., et al., 1994, “Fault Activity Map of California and Adjacent Areas,” California Division of Mines and Geology, Geologic Data Map No. 6. 11. Landmark Engineering Corporation, 1992, “Verification of Bottom of Footing for Cortland Trust Retaining Wall,” September 2. 12. Landmark Engineering Corporation, undated, “Keystone Retaining Wall, Plan View and Profile, Grading Plan, Cameo Highlands,” Sheet 2 of 4. 13. Mark Company, 1994, “Courtland Noise Wall Trust,” June 14. 14. Martin, G. R., and Lew, M., 1999, “Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California,” SCEC, March. 15. Morton and Miller, 1981, Geologic Map of Orange County, CDMG Bulletin 204. 16. Morton, P. K., Miller, R. V., and Evans, J. R., 1976, “Environmental Geology of Orange County, California,” California Division of Mines and Geology, Open File Report 79-8 LA. 17. Morton, Douglas M., and Miller, Fred K., Compilers, 2006, “Geologic Map of the San Bernardino and Santa Ana 30’ X 60’ Quadrangles, California,” U. S. Geological Survey Open File Report 2006-1217. 18. Petersen, M. D., Bryant, W. A., Cramer, C. H., Cao, T., Reichle, M. S., Frankel, A. D., Lienkaemper, J. J., McCrory, P. A., and Schwartz, D. P., 1996, “Probabilistic Seismic Hazard Assessment for the State of California,” Department of Conservation, Division of Mines and Geology, DMG Open-File Report 96-08, USGS Open File Report 96-706. PA2019-107 APPENDIX A REFERENCES (4709 Cortland Drive) R McCarthy Consulting, Inc 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 19. Petra Geotechnical, Inc., 1995, “Subsurface Investigation and Geotechnical Recommendations, Distressed Keystone Wall and Backyard, 4839 Cortland Drive, Corona Del Mar, California,” J.N. 337-92, May 23. 20. Petra Geotechnical, Inc., 1993, “Drain Placement and Backfill at Toe of Crib Wall Adjacent to Pacific Coast Highway, South of Cameo Highlands, Corona del Mar, California,” J.N. 337-92, October 1. 21. Petra Geotechnical, Inc., 1992, “Review of Grading Plan for Construction of Block and Glass Walls, Adjacent to Pacific Coast Highway, South of Cameo Highlands, Corona del Mar, California,” J.N. 337-92, December 26. 22. Petra Geotechnical, Inc., 1992, “Geotechnical Report of Keystone Wall Backfill, Adjacent to Pacific Coast Highway, South of Cameo Highlands, Corona del Mar, California,” J.N. 337-92, December 22. 23. Randle, C. J., 1998, “Certification of Wall Repair and Rear Yard Drainage Re: Residence of Ms. Mary Roach, 4709 Cortland Dr., Corona del Mar, California,” September 29. 24. R McCarthy Consulting, Inc., 2018, “Earthwork Observation/Testing Report, Residential Basement Construction, Cameo Highlands, Tract 3519, Lot 1, 4701 Cortland Drive, Corona del Mar, California,” File No: 8143-10, Report No: 20180717-1, December 17. 25. R McCarthy Consulting, Inc., 2018, Addendum, Evaluation of East Property Line Geologic Conditions, Shoring and Slope Setback Recommendations, Planned Custom Home, 4701 Cortland Drive, Corona del Mar, California,” File No: 8143- 01, Report No: 20180111-1, January 11. 26. R McCarthy Consulting, Inc., 2017, “Geotechnical Investigation, Proposed Residential Construction, 4701 Cortland Drive, Corona del Mar, California,” File No: 8143-00, Report No: 20170214-1, October 17. 27. Tan, Siang, S., and Edgington, William J., 1976, "Geology and Engineering Geology of the Laguna Beach Quadrangle, Orange County, California," California Division of Mines and Geology, Special Report 127. 28. Terzaghi, Karl, Peck, Ralph B., and Mesri, Ghoamreza, 1996, “Soil Mechanics in Engineering Practice, Third Edition,” John Wiley & Sons, Inc. 29. U. S. Geological Survey, Earthquake Hazards Program, 2014, U. S. Seismic Design Maps, U.S. Department of the Interior | U.S. Geological Survey 30. Vedder, J. G., Yerkes, R. F., and Schoellhamer, J. E., 1957, “Geologic Map of the San Joaquin Hills-San Juan Capistrano Area, Orange County, California,” U. S. Geological Survey, Oil and Gas Investigations Map OM-193. PA2019-107 APPENDIX B FIELD EXPLORATION PA2019-107 APPENDIX B FIELD EXPLORATION (4709 Cortland Drive) R McCarthy Consulting, Inc 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 General Subsurface conditions were explored by excavating three hand-auger borings. In addition to the three exploratory borings a recently logged shoring pile boring located on the adjacent property is presented for review. The approximate locations of the borings are shown on the Geotechnical Plot Plan, Figure 1. Boring Logs are included as Figures B-2, B-3, B-4 and B-5. A Key to Logs is included as Figure B-1. Excavation of the borings was observed by our field engineer and geologist who logged the soils and obtained samples for identification and laboratory testing. Exploratory excavations were located in the field by pacing from known landmarks. Their locations as shown are, therefore, within the accuracy of such measurements. Elevations were determined by interpolation between points on the Topographic Survey, Reference 1. Sample Program 1.Hand Augers - Relatively undisturbed drive samples were obtained by utilizing a sampler lined on the inside with brass rings, each 1-inch long and 2.5-inches outside diameter. The sample is typically driven for a total length of about 8-inches. The number of blows per 8-inches of driving are recorded on the boring logs. The slide hammer used to drive the samples has a weight of 10.3 pounds with effort. The slide hammer drop height was 18-inches. The hammer weight alone was not sufficient to drive the sample; additional energy was applied by the drilling operator by thrust force on the hammer from the topmost position. The brass rings were removed from the sampler and transferred into a plastic tube and sealed. 2.Bulk samples representative of subsurface conditions were collected from the excavations and sealed in plastic bags. Summary The soils were classified based on field observations and laboratory tests. The classification is in accordance with ASTM D2487 (the Unified Soil Classification System). Collected samples were transported to the laboratory for testing. No groundwater was encountered in the borings. PA2019-107 UNIFIED SOIL CLASSIFICATION CHART CLEAN GRAVELS GRAVEL WITH FINES CLEAN SANDS SANDS WITH FINES GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT GROUP SYMBOLS SYMBOLMAJOR DIVISIONS TYPICAL NAMES HIGHLY ORGANIC SOILS SILTS AND CLAYS: Liquid Limit 50% or less SILTS AND CLAYS: Liquid Limit greater than 50% Well graded gravels and gravel-sand mixtures, little or no fines Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Poorly graded gravels and gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well graded sands and gravelly sand, little or no fines Poorly graded sands and gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts, very fine sands, rock flour, silty or clayey fine sands Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic clays Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity Peat, muck, and other highly organic soils KEY TO LOGS COARSE-GRAINED SOILS: more than 50% retained on No. 200 sieve (based on the material passing the 3-inch [75mm] sieve) FINE-GRAINED SOILS: 50% or more passes No. 200 sieve* GRAVELS: 50% or more of coarse fraction retained on No. 4 sieve SANDS: more than 50% of coarse fraction passes No. 4 sieve Water level SYMBOL Figure B-1: Unied Soil Classication Chart / Key To Logs NOTATION SAMPLER TYPE C Core barrel CA California split-barrel sampler with 2.5-inch outside diameter and a 1.93-inch inside diameter D&M Dames & Moore piston sampler using 2.5-inch outside diameter, thin-walled tube O Osterberg piston sampler using 3.0-inch outside diameter, thin-walled Shelby tube PTB Pitcher tube sampler using 3.0-inch outside diameter, thin-walled Shelby tube S&H Sprague & Henwood split-barrel sampler with a 3.0-inch outside diameter and a 2.43-inch inside diameter SPT Standard Penetration Test (SPT) split-barrel sampler with a 2.0-inch outside diameter and a 1.5-inch inside diameter ST Shelby Tube (3.0-inch outside diameter, thin-walled tube) advanced with hydraulic pressure NR No Recovery Modified California Sampler (3" O.D.) Modified California Sampler, no recovery Standard Penetration Test, ASTM D 1586 Standard Penetration Test, no recovery Thin-walled tube sample using Pitcher barrel Thin-walled tube sample, pushed or used Osterberg sampler Disaggregated (bulk) sample PA2019-107 FIGURE R MCCARTHY CONSULTING, INC. 23.1 MONTEREY FORMATION ( Tm ) At 1.5 - 3': Yellow brown clayey SILTSTONE, moist, medium dense, weathered in upper 8" T.D. - 3 feet (refusal on bedrock) No groundwater 4709 Cortland (SW Base of Retaining Wall Along PCH)SITE LOCATION: DATE: 10/16/2018 EQUIPMENT: SURFACE ELEVATION: Hand- Auger SM BY: GM147 +/- 10 88 0 66 44 B-2LOG OF BORINGDRY DENSITY (PCF)DEPTHNOTESMATERIAL DESCRIPTION BORING NO: HA-1 DEPTHUSCSBLOW COUNTIN-PLACE SAMPLEBAG SAMPLEMOISTURE (%)22 0ARTIFICIAL FILL (Af) At 0 - 1.5': Reddish brown fine to medium grained silty SAND, moist, medium dense, abundant rock fragments 10 FILE NO:8283-00 PA2019-107 FIGURELOG OF BORING B-3 R MCCARTHY CONSULTING, INC. 6 6 4 4 0 SM SITE LOCATION:4709 Cortland (NW Base of Retaining Wall Along PCH)EQUIPMENT: Hand- Auger SURFACE ELEVATION: 146 +/- BY: GM BLOW COUNTIN-PLACE SAMPLEBAG SAMPLEMOISTURE (%)DRY DENSITY (PCF)NOTES DEPTHBORING NO: HA-2 10 10 FILE NO:8283-00 8 8 2 2 ARTIFICIAL FILL (Af) At 0-2': Reddish brown fine to medium grained silty SAND, moist, loose, with abundant gravel T.D. - 2 feet (refusal on utility line running parallel to PCH) No groundwater MATERIAL DESCRIPTIONDEPTHUSCS 0 DATE: 10/16/2018 PA2019-107 FIGURE ~ 6" Planter Soil ARTIFICIAL FILL (Af) At 0.5 - 4.5': Reddish brown fine to medium grained clayey SAND/sandy CLAY, very moist, medium dense, fine to coarse rock fragments At 3' No recovery At 10': Reddish brown fine to medium grained clayey to silty SAND/sandy CLAY, very moist, medium dense, abundant fine rock fragmentsSM/ SC/ CL SC/ CL SC/ CL MONTEREY FORMATION ( Tm ) At 13 - 13.5': Pale olive grey to yellow brown clayey SILTSTONE, moist, medium dense, weathered in upper 12", plastic 8 8 9/6" 17.9 SITE LOCATION:4709 Cortland (6' from wall, middle of rear yard)EQUIPMENT: Hand- Auger DATE: 10/16/2018 SURFACE ELEVATION: 161 +/- BY: GM FILE NO:8283-00 LOG OF BORING B-4 20 20 R MCCARTHY CONSULTING, INC. T.D. - 13.5 feet (refusal on bedrock) No groundwater 16 16 12 12 18.6 17.2 4 4 0 0DEPTHUSCSBLOW COUNTIN-PLACE SAMPLEBAG SAMPLEMOISTURE (%)DRY DENSITY (PCF)NOTES DEPTHBORING NO: HA-3 MATERIAL DESCRIPTION At 8.5': Reddish brown clayey SAND/sandy CLAY, very moist, medium dense, abundant fine rock fragments PA2019-107 FIGURE B-5LOG OF BORINGDRY DENSITY (PCF)DEPTHNOTESMATERIAL DESCRIPTION BORING NO: P14 DEPTHUSCSBLOW COUNTIN-PLACE SAMPLEBAG SAMPLEMOISTURE (%)88 0 40 FILE NO:8283-00 40 3232 0 2424 1616 30SM/ SC BY: PA+/- 159 4701 Cortland Drive, Corona del MarSITE LOCATION: DATE: 5/18/2018 EQUIPMENT: SURFACE ELEVATION: Drilco Auger Boring SM 16 End at 23.5 feet, no groundwater encountered. R MCCARTHY CONSULTING, INC. 0-11' Artificial Fill (Af): Silty SAND and Clayey SAND, reddish brown, fine to medium grained , moist, medium dense, with abundant bedrock fragments 11 - 23.5' Monterey Formation ( Tm ): Clayey SILTSTONE, pale olive gray to yellow brown, moist, medium dense PA2019-107 APPENDIX C LABORATORY TESTING PA2019-107 APPENDIX C LABORATORY TESTING (4709 Cortland Drive) R McCarthy Consulting, Inc 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 The laboratory testing program was designed to fit the specific needs of this project and was limited to testing the soil samples collected during the on-site exploration. The test program was performed by our laboratory. Soils were classified visually and per the results of our laboratory testing according to ASTM D2487, the Unified Soil Classification System (USCS). The field moisture content and dry densities of the soils encountered were determined by performing laboratory tests on the collected samples. The results of the moisture tests, density determinations and soil classifications are shown on the Boring Logs, Figures B-2 through B-4. Grain Size Determination Particle size analysis consisting of mechanical sieve analysis were performed on representative samples of the on-site soils in accordance with ASTM D 1140 and C-136. The test results are presented on Figures C-1 through C-4. Atterberg Limits Atterberg Limits were determined on a representative sample of the on-site soils in accordance with ASTM D 4318. The test results are presented on Figures C-5. Direct Shear Direct shear tests representative of the Monterey Formation bedrock are presented in Figures C-6 and C-7. The samples were from a nearby site in Cameo Shores to the south at 4615 Orrington Road. Direct shear tests were performed on selected undisturbed samples which were saturated under a surcharge equal to the applied normal force during testing. The apparatus used is in conformance with the requirements outlined in ASTM: D3080. The test specimens, approximately 2.5 inches in diameter and 1 inch in height, were subjected to simple shear along a plane at mid-height after allowing time for pore pressure dissipation prior to application of shearing force. The samples were tested under various normal loads, a different specimen being used for each normal load. The samples were sheared at a constant rate of strain of 0.005 inches per minute. Shearing of the specimens was continued until the shear stress became essentially constant or until a deformation of approximately 10 percent of the original diameter was reached. The peak and ultimate shear stress values were plotted versus applied normal stress, and a best-fit straight line through the plotted points was determined to arrive at the cohesion and the angle of internal friction parameters of the soil samples. PA2019-107 CLPARTICLE SIZE ANALYSIS COMPARISONFile No.: 8283-00 Date:C-1Medium1.5'Brown Sandy CLAY with Gravel55.3SAMPLE IDENTIFICATIONFigure No.:CULOCATIONDEPTH (FT) COBBLEGRAVELSANDJanuary 2019HA-1SILTSOIL DESCRIPTION CoarseCCFineUSCSCLAYPASSING NO. 200 (%)01020304050607080901000.0010.0100.1001.00010.000100.000PERCENT PASSINGPARTICLE SIZE (MILLILMETERS)PARTICLE SIZE (INCHES OR SIEVE NO.)3" 1 1/2" 3/4" 3/8" 4 10 20 40 60 100 200PA2019-107 USCSCLAYPASSING NO. 200 (%) COBBLEGRAVELSANDJanuary 2019HA-3SILTSOIL DESCRIPTION CoarseCCFineMedium3.5'Brown Clayey SAND with gravel35.1SAMPLE IDENTIFICATIONCULOCATIONDEPTH (FT)SCPARTICLE SIZE ANALYSIS COMPARISONFile No.: 8283-00 Date:C-2Figure No.:01020304050607080901000.0010.0100.1001.00010.000100.000PERCENT PASSINGPARTICLE SIZE (MILLILMETERS)PARTICLE SIZE (INCHES OR SIEVE NO.)3" 1 1/2" 3/4" 3/8" 4 10 20 40 60 100 200PA2019-107 SCPARTICLE SIZE ANALYSIS COMPARISONFile No.: 8283-00 Date:C-3Medium5.5'Brown Clayey SAND with gravel40.1SAMPLE IDENTIFICATIONFigure No.:CULOCATIONDEPTH (FT) COBBLEGRAVELSANDJanuary 2019HA-3SILTSOIL DESCRIPTION CoarseCCFineUSCSCLAYPASSING NO. 200 (%)01020304050607080901000.0010.0100.1001.00010.000100.000PERCENT PASSINGPARTICLE SIZE (MILLILMETERS)PARTICLE SIZE (INCHES OR SIEVE NO.)3" 1 1/2" 3/4" 3/8" 4 10 20 40 60 100 200PA2019-107 USCSCLAYPASSING NO. 200 (%) COBBLEGRAVELSANDJanuary 2019HA-3SILTSOIL DESCRIPTION CoarseCCFineMedium11'Brown Clayey SAND with gravel33.5SAMPLE IDENTIFICATIONCULOCATIONDEPTH (FT)SCPARTICLE SIZE ANALYSIS COMPARISONFile No.: 8283-00 Date:C-4Figure No.:01020304050607080901000.0010.0100.1001.00010.000100.000PERCENT PASSINGPARTICLE SIZE (MILLILMETERS)PARTICLE SIZE (INCHES OR SIEVE NO.)3" 1 1/2" 3/4" 3/8" 4 10 20 40 60 100 200PA2019-107 C-5 38 Date:January 2019 Figure No.: PLASTICITY INDEX LIQUID LIMIT USCS CL SAMPLE IDENTIFICATION LOCATION DEPTH (FT) HA-3 5.5' 23 ATTERBERG LIMITS File No.: 8283-00 30 35 40 45 50 10 100Moisture Content (%)Number of Blows Flow Curve MH or OH ML or OLCL-ML 0 10 20 30 40 50 60 70 0 102030405060708090100Plasticity Index (PI)Liquid Limit (LL) PA2019-107 Initial Dry Density Avg: 115 pcfIntitial Moisture Content % Avg: 15 %RESULTS PEAKULTIMATEProject: 4615 Orrington Road, Corona del MarBoring: B-1 Sample Depth: 9.0 ftSample Description: Clayey SAND (SC)Test Condition: Inundated; shear rate=0.001313 in/minCohesion 190 psf277 psfFriction Angle 36 deg34 degFILE NO: 8117-00FIGURE: C-6y = 0.7352x + 184.5y = 0.6736x + 277010002000300040005000600070000 1000 2000 3000 4000 5000 6000 7000 8000 9000Shear Stress (psf)Normal Load (psf)Direct Shear Test Results B‐1 @ 9.0 ft (Undisturbed) Maximum Shear Reading (psf)Ultimate Shear Reading (psf)Linear (Maximum Shear Reading (psf))Linear (Ultimate Shear Reading (psf))PA2019-107 Initial Dry Density Avg: 109 pcf Intitial Moisture Content % Avg: 9 % RESULTS PEAK ULTIMATE Project: 4615 Orrington Road, Corona del Mar Boring: B-1 Sample Depth: 18.0 ft Sample Description: SANDSTONE Test Condition: Inundated; shear rate=0.001382 in/min Cohesion 0 psf 149 psf Friction Angle 46 deg 37 deg FILE NO: 8117-00 FIGURE: C-7 y = 0.9651x + 624.5 y = 0.7479x + 148.5 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000Shear Stress (psf)Normal Load (psf) Direct Shear Test Results B-1 @ 18.0 ft (Undisturbed) Maximum Shear Reading (psf) Ultimate Shear Reading (psf) Linear (Maximum Shear Reading (psf)) Linear (Ultimate Shear Reading (psf)) PA2019-107 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 APPENDIX D STANDARD GRADING GUIDELINES PA2019-107 APPENDIX D STANDARD GRADING GUIDELINES (4709 Cortland Drive) R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 GENERAL These Guidelines present the usual and minimum requirements for grading operations observed by R McCarthy Consulting, Inc., or its designated representative. No deviation from these guidelines will be allowed, except where specifically superseded in the geotechnical report signed by a registered geotechnical engineer. The placement, spreading, mixing, watering, and compaction of the fills in strict accordance with these guidelines shall be the sole responsibility of the contractor. The construction, excavation, and placement of fill shall be under the direct observation of the geotechnical engineer or any person or persons employed by the licensed geotechnical engineer signing the soils report. If unsatisfactory soil-related conditions exist, the geotechnical engineer shall have the authority to reject the compacted fill ground and, if necessary, excavation equipment will be shut down to permit completion of compaction. Conformance with these specifications will be discussed in the final report issued by the geotechnical engineer. SITE PREPARATION All brush, vegetation and other deleterious material such as rubbish shall be collected, piled and removed from the site prior to placing fill, leaving the site clear and free from objectionable material. Soil, alluvium, or rock materials determined by the geotechnical engineer as being unsuitable for placement in compacted fills shall be removed from the site. Any material incorporated as part of a compacted fill must be approved by the geotechnical engineer. The surface shall then be plowed or scarified to a minimum depth of 6 inches until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment used. After the area to receive fill has been cleared and scarified, it shall be disced or bladed by the contractor until it is uniform and free from large clods, brought to the proper moisture content and compacted to minimum requirements. If the scarified zone is greater than 12 inches in depth, the excess shall be removed and placed in lifts restricted to 6 inches. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipe lines or others not located prior to grading are to be removed or treated in a manner prescribed by the geotechnical engineer. MATERIALS Materials for compacted fill shall consist of materials previously approved by the geotechnical engineer. Fill materials may be excavated from the cut area or imported from other approved PA2019-107 APPENDIX D STANDARD GRADING GUIDELINES (4709 Cortland Drive) R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 sources, and soils from one or more sources may be blended. Fill soils shall be free from organic (vegetation) materials and other unsuitable substances. Normally, the material shall contain no rocks or hard lumps greater than 6 inches in size and shall contain at least 50 percent of material smaller than 1/4-inch in size. Materials greater than 4 inches in size shall be placed so that they are completely surrounded by compacted fines; no nesting of rocks shall be permitted. No material of a perishable, spongy, or otherwise of an unsuitable nature shall be used in the fill soils. Representative samples of materials to be utilized, as compacted fill shall be analyzed in the laboratory by the geotechnical engineer to determine their physical properties. If any material other than that previously tested is encountered during grading, the appropriate analysis of this material shall be conducted by the geotechnical engineer in a timely manner. PLACING, SPREADING, AND COMPACTING FILL MATERIAL Soil materials shall be uniformly and evenly processed, spread, watered, and compacted in thin lifts not to exceed 6 inches in thickness. Achievement of a uniformly dense and uniformly moisture conditioned compacted soil layer should be the objective of the equipment operators performing the work for the Owner and Contractor. When the moisture content of the fill material is below that specified by the geotechnical engineer, water shall be added by the contractor until the moisture content is near optimum as specified. Moisture levels should generally be at optimum moisture content or greater. When the moisture content of the fill material is above that specified by the geotechnical engineer, the fill material shall be aerated by the contractor by blading, mixing, or other satisfactory methods until the moisture content is near the specified level. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted to 90 percent of the maximum laboratory density in compliance with ASTM D1557 (five layers). Compaction shall be accomplished by sheepsfoot rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compacting equipment. Equipment shall be of such design that it will be able to compact the fill to the specified density. Compaction shall be continuous over the entire area and the equipment shall make sufficient passes to obtain the desired density uniformly. A minimum relative compaction of 90 percent out to the finished slope face of all fill slopes will be required. Compacting of the slopes shall be accomplished by backrolling the slopes in increments of 2 to 5 feet in elevation gain or by overbuilding and cutting back to the compacted inner core, or by any other procedure, which produces the required compaction. GRADING OBSERVATIONS The geotechnical engineer shall observe the fill placement during the course of the grading process and will prepare a written report upon completion of grading. The compaction report shall make a statement as to compliance with these guidelines. PA2019-107 APPENDIX D STANDARD GRADING GUIDELINES (4709 Cortland Drive) R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 As a minimum, one density test shall be required for each 2 vertical feet of fill placed, or one for each 1,000 cubic yards of fill, whichever requires the greater number of tests; however, testing should not be limited based on these guidelines and more testing is generally preferable. Processed ground to receive fill, including removal areas such as canyon or swale cleanouts, must be observed by the geotechnical engineer and/or engineering geologist prior to fill placement. The contractor shall notify the geotechnical engineer when these areas are ready for observation. UTILITY LINE BACKFILL Utility line backfill beneath and adjacent to structures; beneath pavements; adjacent and parallel to the toe of a slope; and in sloping surfaces steeper than ten horizontal to one vertical (10:1), shall be compacted and tested in accordance with the criteria given in the text of this report. Alternately, relatively self-compacting material may be used. The material specification and method of placement shall be recommended and observed by the soil engineer, and approved by the geotechnical engineer and Building Official before use and prior to backfilling. Utility line backfill in areas other than those stated above are generally subject to similar compaction standards and will require approval by the soil engineer. The final utility line backfill report from the project soil engineer shall include an approval statement that the backfill is suitable for the intended use. PROTECTION OF WORK During the grading process and prior to the complete construction of permanent drainage controls, it shall be the responsibility of the contractor to provide good drainage and prevent ponding of water and damage to adjoining properties or to finished work on the site. After the geotechnical engineer has finished observations of the completed grading, no further excavations and/or filling shall be performed without the approval of the geotechnical engineer. PA2019-107 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150 Newport Beach, CA 92660 Phone 949-629-2539 APPENDIX E SEISMICITY DATA PA2019-107 9/20/2017 Design Maps Summary Report https://earthquake.usgs.gov/cn1/designmaps/us/summary.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0…1/1 Report Title Building Code Reference Document Site Coordinates Site Soil Classification Risk Category Design Maps Summary Report User–Specified Input 4701 Cortland Dr., Corona del Mar Thu September 21, 2017 03:58:57 UTC ASCE 7-10 Standard (which utilizes USGS hazard data available in 2008) 33.5896°N, 117.8582°W Site Class D – “Stiff Soil” I/II/III USGS–Provided Output SS =1.677 g SMS =1.677 g SDS =1.118 g S1 =0.611 g SM1 =0.917 g SD1 =0.611 g For information on how the SS and S1 values above have been calculated from probabilistic (risk-targeted) and deterministic ground motions in the direction of maximum horizontal response, please return to the application and select the “2009 NEHRP” building code reference document. For PGAM, TL, CRS, and CR1 values, please view the detailed report. Although this information is a product of the U.S. Geological Survey, we provide no warranty, expressed or implied, as to the accuracy of the data contained therein. This tool is not a substitute for technical subject-matter knowledge. PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…1/6 From Figure 22-1 [1] From Figure 22-2 [2] Design Maps Detailed Report ASCE 7-10 Standard (33.5896°N, 117.8582°W) Site Class D – “Stiff Soil”, Risk Category I/II/III Section 11.4.1 — Mapped Acceleration Parameters Note: Ground motion values provided below are for the direction of maximum horizontal spectral response acceleration. They have been converted from corresponding geometric mean ground motions computed by the USGS by applying factors of 1.1 (to obtain SS) and 1.3 (to obtain S1). Maps in the 2010 ASCE-7 Standard are provided for Site Class B. Adjustments for other Site Classes are made, as needed, in Section 11.4.3. SS = 1.677 g S1 = 0.611 g Section 11.4.2 — Site Class The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or the default has classified the site as Site Class D, based on the site soil properties in accordance with Chapter 20. Table 20.3–1 Site Classification Site Class vS N or Nch su A. Hard Rock >5,000 ft/s N/A N/A B. Rock 2,500 to 5,000 ft/s N/A N/A C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 >2,000 psf D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf E. Soft clay soil <600 ft/s <15 <1,000 psf Any profile with more than 10 ft of soil having the characteristics: Plasticity index PI > 20, Moisture content w ≥ 40%, and Undrained shear strength su < 500 psf F. Soils requiring site response analysis in accordance with Section 21.1 See Section 20.3.1 For SI: 1ft/s = 0.3048 m/s 1lb/ft² = 0.0479 kN/m² PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…2/6 Section 11.4.3 — Site Coefficients and Risk–Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration Parameters Table 11.4–1: Site Coefficient Fa Site Class Mapped MCE R Spectral Response Acceleration Parameter at Short Period SS ≤ 0.25 SS = 0.50 SS = 0.75 SS = 1.00 SS ≥ 1.25 A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.2 1.2 1.1 1.0 1.0 D 1.6 1.4 1.2 1.1 1.0 E 2.5 1.7 1.2 0.9 0.9 F See Section 11.4.7 of ASCE 7 Note: Use straight–line interpolation for intermediate values of SS For Site Class = D and SS = 1.677 g, Fa = 1.000 Table 11.4–2: Site Coefficient Fv Site Class Mapped MCE R Spectral Response Acceleration Parameter at 1–s Period S1 ≤ 0.10 S1 = 0.20 S1 = 0.30 S1 = 0.40 S1 ≥ 0.50 A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.7 1.6 1.5 1.4 1.3 D 2.4 2.0 1.8 1.6 1.5 E 3.5 3.2 2.8 2.4 2.4 F See Section 11.4.7 of ASCE 7 Note: Use straight–line interpolation for intermediate values of S1 For Site Class = D and S1 = 0.611 g, Fv = 1.500 PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…3/6 Equation (11.4–1): Equation (11.4–2): Equation (11.4–3): Equation (11.4–4): From Figure 22-12 [3] SMS = FaSS = 1.000 x 1.677 = 1.677 g SM1 = FvS1 = 1.500 x 0.611 = 0.917 g Section 11.4.4 — Design Spectral Acceleration Parameters SDS = ⅔ SMS = ⅔ x 1.677 = 1.118 g SD1 = ⅔ SM1 = ⅔ x 0.917 = 0.611 g Section 11.4.5 — Design Response Spectrum TL = 8 seconds Figure 11.4–1: Design Response Spectrum PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…4/6 Section 11.4.6 — Risk-Targeted Maximum Considered Earthquake (MCER) Response Spectrum The MCER Response Spectrum is determined by multiplying the design response spectrum above by 1.5. PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…5/6 From Figure 22-7 [4] Equation (11.8–1): From Figure 22-17 [5] From Figure 22-18 [6] Section 11.8.3 — Additional Geotechnical Investigation Report Requirements for Seismic Design Categories D through F PGA = 0.688 PGAM = FPGAPGA = 1.000 x 0.688 = 0.688 g Table 11.8–1: Site Coefficient FPGA Site Class Mapped MCE Geometric Mean Peak Ground Acceleration, PGA PGA ≤ 0.10 PGA = 0.20 PGA = 0.30 PGA = 0.40 PGA ≥ 0.50 A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.2 1.2 1.1 1.0 1.0 D 1.6 1.4 1.2 1.1 1.0 E 2.5 1.7 1.2 0.9 0.9 F See Section 11.4.7 of ASCE 7 Note: Use straight–line interpolation for intermediate values of PGA For Site Class = D and PGA = 0.688 g, FPGA = 1.000 Section 21.2.1.1 — Method 1 (from Chapter 21 – Site-Specific Ground Motion Procedures for Seismic Design) CRS = 0.902 CR1 = 0.922 PA2019-107 9/20/2017 Design Maps Detailed Report https://earthquake.usgs.gov/cn1/designmaps/us/report.php?template=minimal&latitude=33.5896&longitude=-117.8582&siteclass=3&riskcategory=0&e…6/6 Section 11.6 — Seismic Design Category Table 11.6-1 Seismic Design Category Based on Short Period Response Acceleration Parameter VALUE OF SDS RISK CATEGORY I or II III IV SDS < 0.167g A A A 0.167g ≤ SDS < 0.33g B B C 0.33g ≤ SDS < 0.50g C C D 0.50g ≤ SDS D D D For Risk Category = I and SDS = 1.118 g, Seismic Design Category = D Table 11.6-2 Seismic Design Category Based on 1-S Period Response Acceleration Parameter VALUE OF SD1 RISK CATEGORY I or II III IV SD1 < 0.067g A A A 0.067g ≤ SD1 < 0.133g B B C 0.133g ≤ SD1 < 0.20g C C D 0.20g ≤ SD1 D D D For Risk Category = I and SD1 = 0.611 g, Seismic Design Category = D Note: When S1 is greater than or equal to 0.75g, the Seismic Design Category is E for buildings in Risk Categories I, II, and III, and F for those in Risk Category IV, irrespective of the above. Seismic Design Category ≡ “the more severe design category in accordance with Table 11.6-1 or 11.6-2” = D Note: See Section 11.6 for alternative approaches to calculating Seismic Design Category. References 1. Figure 22-1: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-1.pdf 2. Figure 22-2: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-2.pdf 3. Figure 22-12: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-12.pdf 4. Figure 22-7: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-7.pdf 5. Figure 22-17: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-17.pdf 6. Figure 22-18: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-18.pdf PA2019-107 R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150 Newport Beach, CA 92660 Phone 949-629-2539 APPENDIX F Figure Excerpts from Reference 23 PA2019-107 PA2019-107 PA2019-107 PA2019-107 PA2019-107