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HomeMy WebLinkAboutX2017-3235 - Soils (2)3 CONSULTING, INC July 23, 2018 Mr. Scottie Upshall 3803 Marcus Avenue Newport Beach, California 92663 Subject: Earthwork Observation/Testing Report Proposed Residential Construction 3803 Marcus Avenue Newport Island Newport Beach, California Permit No: 2245-2017 References: See Attached List X 9061-V 35 3 $03 mat'cus Ave File No: 8154-10 Report No: 20180709-2 This report presents the results of our observation and testing services performed during the grading of the property located at 3803 Marcus Avenue, Newport Island, City of Newport Beach, California. The purpose for our geotechnical services was to observe and document the grading operations as part of the development of a graded pad area for the construction of a new single-family custom home. Based on our observations, and review of the test results, it is our opinion that the grading was performed in substantial conformance with the City of Newport Beach and project grading requirements. SITE DESCRIPTION The subject property is located on the southern side of Newport Island, on the southwest side of Marcus Avenue, and immediately southeast of Newport Island Park. The nearest cross street is 38t' Street to the south. The southwest side of the property borders the Rivo Alto Channel and the southeast side is adjacent to a developed residential property (Lot 1). There is a backyard deck, gangway and boat dock that extend over and into the Rivo Alto Channel on the southwest. PROIECT DATA Site: 3803 Marcus Avenue, Lot 2, Block 338 Newport Island, Newport Beach, California Owner: Scottie Upshall 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Phone 949 629 2539 1 Email info@Rmccarthyconsulting.com I July 23, 2018 General Contractor: Spinnaker Development, Inc. Civil Engineer: Forkert Engineering, Inc. Regulatory Agency: City of Newport Beach Grading Contractor: Tight Quarters, Inc. File No: 8154-10 Report No: 20180709-2 Page: 2 Gradin Pg lans: "Precise Grading Plan, 3803 Marcus Avenue, Newport Beach, CA," prepared by Forkert Engineering and Surveying, Inc., Sheet C-2, November 15, 2017 (latest revision). Geotechnical Observation Period: GRADING AND EARTHWORK A. General May 8, 2018, through July 5, 2018 The former site structures, improvements and vegetation were demolished and cleared from the property prior to and during grading. The site excavation exposed marine deposits. Marine deposits were encountered at depths of about 2 to 7 feet within the building pad excavations. Site conditions were, therefore, generally as expected based on preliminary exploration as reported in the attached references. B. Preparation of Existing Ground a. Building Pad Along the northeast approximately one-third of the site, ground preparation consisted of overexcavation of existing earth materials to expose marine deposits consisting of pale yellowish -brown sand and locally dark gray highly plastic clay at a depth of 3.5 -feet. Following removals, I foot of on-site soil was cement treated and processed in place. The deadman and tiebacks were then constructed for the seawall as described below. Along the southwest approximately two-thirds of the site, the removal bottom was excavated to approximately 3.5 feet below existing grades subsequent to installation of the deadman. Ground water was generally present within the removal bottom. The recommendations for stabilization consisting of placement of geofabric and rock were therefore implemented within the back two-thirds of the site on both sides of the deadman. Mirafi 140N Geotextile fabric was placed at the bottom of the excavation between the deadman and the seawall and northeast of the deadman, followed by placement of a layer of imported I -inch R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150. Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 3 minus crushed gravel with a thickness of about 1.5 feet, which was then covered with the geofabric. Excavations thus prepared were determined to be suitable for support of fill soils. b. Seawall Tie -backs and Deadman Installation of the seawall tiebacks and new deadman was carried out prior to remedial excavation and fill placement for the southwest side of the building pad at the site. The excavation was made at low tide in late May, 2018. When grade was reached, 140N Mirafi Geotextile fabric was placed at the bottom of the excavation and imported I -inch minus crushed gravel was backfilled approximately 1.5 feet. The Contractor determined the base of the deadman to be about 7 feet below finished grade. The preparation of the foundation bottom was observed and approved by our office on May 23 through May 25, 2018. C. Fill Placement and Compaction Prior to placement of fill, the exposed materials were prepared as described above. Subsequent fill soils were mixed with cement and then generally placed in 6- to 8 -inch loose lifts, brought to near optimum moisture content and compacted. Test results indicated that a minimum of 90 percent relative compaction, as determined by ASTM D1557, was achieved. The maximum depth of fill placed was on the order of 7 feet in the building pad. Fill material consisted of on-site cement -treated silty sands, clayey sands and gravel. Equipment used for compaction included a Kubota SVL90-2 Skid -loader and hand operated equipment. Based on the results of our field density testing, it is our opinion that a minimum of 90 percent relative compaction was achieved. Density tests were performed in accordance with ASTM D1556 (Sand Cone Method) and/or ASTM D6938 (Nuclear Gauge Method). Field Density Test Results are tabulated in Table 1, Results of Field Density Tests. The approximate locations of density tests are on the Geotechnical Plot Plan, Figure I. Representative samples of the site soils used as fill were returned to the laboratory for testing. Laboratory tests for maximum density and optimum moisture content were performed in accordance with ASTM D1557 (the Five Layer Method). The results are presented in Table 2, Laboratory Maximum Dry Density/Optimum Moisture Relationship. Testing was performed on representative areas to render a professional opinion as to the compaction of fill materials. It is our opinion that sufficient testing was performed to arrive at the conclusions stated herein; however, this is an opinion and is not a warranty that all fill materials are at 90 percent relative compaction. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 4 CONCLUSIONS AND RECOMMENDATIONS General Based upon field observations and test results, it is our opinion that grading and compaction described herein was accomplished in accordance with the project requirements and the grading requirements of the City of Newport Beach. Field density testing indicated that a minimum of 90 percent relative compaction was achieved at the locations tested as part of the building pad and site grading. Based on the observations and testing as described herein, the fill materials placed within the building pad area at the site are considered suitable for the intended use. The on-site soils were determined to have a very low expansion potential. Foundation Desien Conditions were as anticipated in the referenced reports. An 18 -inch thick concrete mat slab is planned as indicated on the approved building plans. The recommendations in the referenced reports are applicable to construction. The Contractor should verify that the finished pad grade is at an appropriate level for the installation of the subslab materials and the concrete slab. Concrete Construction Components in Contact with Soil The onsite soils are expected to have a moderate soluble sulfate content and due to shallow sea water levels in the area, a moderate exposure to sulfate can be expected for concrete placed in contact with on-site soils. Various components within the concrete may be subject to corrosion overtime when exposed to soluble sulfates. To help mitigate corrosion, sulfate resistant cement should be used in concrete that may be in contact with on-site soils or ground source water. Attention to maximum water -cement ratio and the minimum compressive strength may also help mitigate deterioration of concrete components. Type V cement is therefore recommended with a maximum water -cement ratio of 0.5 percent. The minimum concrete compressive strength should be at least 4,000 pounds per square inch. 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 California Building Code, Section 1904 and 1905 be utilized, which refers to ACI 318. Testing should be performed during grading when fill materials are identified to confirm the sulfate concentration. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 5 Metal Construction Components in Contact with Soil Soil Resistivity Test results indicate that the on-site soils are corrosive (minimum resistivity value of 445 Ohm -cm). Metal rebar encased in concrete, iron pipes, copper pipes, lift/elevator shafts, air conditioner units, etc., that are in contact with soil or water that permeates the soil should be protected from corrosion that may result from salts and chemicals contained in the soil. In particular, elevator shafts and components are susceptible to corrosion, based on experience in the local area. Methods to mitigate damage due to corrosive soils should be provided by a qualified corrosion specialist. 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. 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. The Owner should be aware of the potential problems that could develop when drainage is altered through construction of 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. Limited water infiltration is allowed as indicated in the referenced letters. These features are part of the civil engineering plans and should be installed and maintained per the plans. Finished Grade and Surface Drainage Finished grades should be constructed per the civil engineering drawings. Roofs should be guttered and discharge conducted away from the house in a non-erosive manner as specified by the Project Civil Engineer or Landscape Architect. Proper interception and disposal of on-site surface discharge is presumed to be a matter of civil engineering or landscape architectural design. Utility Trench Backfill All trench backfills of any kind must be observed and tested by the Geotechnical Engineer. Utility line backfill beneath and adjacent to structures; beneath pavements shall be compacted and tested in accordance with City requirements. A minimum relative compaction of 90 percent is required. Alternately, relatively self -compacting material may be used. The material specification and method of placement shall be recommended and inspected by the Soil Engineer and approved by the Building Official prior to backfilling. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8 154- 10 Report No: 20180709-2 Page: 6 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. No concrete hardscape/flatwork should be poured at the site until a written approval memo is provided by the Soil Engineer. Construction Considerations 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, slopes 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. Observation and Testing 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 representative shall visit the site at intervals appropriate to the stage of construction, as notified by the Contractor, in order to observe the progress and quality of 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, as an experienced professional, to become generally familiar with the work in progress and to determine, in general, if the work is proceeding in accordance with the recommendations of this report. R McCarthy Consulting shall not direct, supervise, or have control over the Contractor's work nor have any responsibility for the construction means, methods, techniques, sequences, or procedures selected by the Contractor nor 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 shall not be responsible for any acts or omission of the Contractor, Subcontractor, any entity performing any portion of the work, or any agents or employees of any of them. R McCarthy Consulting does not guarantee the performance of 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. These observations are conducted on a time and material basis. The responsibility for timely notification of the start of construction and ongoing geotechnical involved phases of construction is that of the Owner and the Contractor(s). Typically, at least 48 hours' notice is required. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 7 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 foundations, trenching, exterior site improvements, etc.; • To observe side cut excavations for retaining walls, trenches, etc.; • To test for proper moisture content and proper degree of compaction of fill; • To check that foundation excavations are clean and founded in competent material; • To check the slab subgrade materials prior to placing the gravel, vapor barrier and concrete; • 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 and sidewalk subgrade materials; do not pour any concrete flatwork without an approval memo from our office. • 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. Subsequent Grading Operations Prior to the commencement of additional grading operations on-site including items such as utility trenches, hardscape, drainage improvements, retaining wall drain installation and backfill, etc., we recommend to the Owner that our office be notified to provide appropriate recommendations and observation and testing services as required. LIMITATIONS Our description of grading operations, as well as observations and testing, has been limited to those grading operations observed between May 8, 2018, and July 5, 2018. This report does not include line and grade survey results. Elevations and locations used in this report are estimated based on field surveys done by others. The opinions rendered apply to conditions in the subject areas observed by us as of the date of our indicated site visits. We are not responsible for any changes in the conditions that may occur after that date and outside our purview. Our work is considered to be in accordance with the usual standards of the profession and with local practice. No other warranty is expressed or implied. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 8 The opportunity to be of service is appreciated. If you have any questions, please call. Respectfully submitted, R MCCARTHY CONSULTING, INC. Robert J. cCarthy, 0 Geotechnical Engineer Registration Expires 3-31-20 Date Signed: 7/24/18 Attachments: Figure I, Geotechnical Plot Plan Table I — Results of Field Density Tests Table 2 — Laboratory Maximum Dry Density/Optimum Moisture Relationship Table 3 — Chemical Tests Table 4 — Expansion Index Test Results References R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 9 TABLE I — RESULTS OF FIELD DENSITY TESTS Test No. Test Date Location Elevation (feet) Soil Type Moisture Content (%) Dry Density (pcf) Relative Compaction 1 5/8/18 Building Pad -3.5 2 1 1.7 116.3 94 2 Grayish -brown silty SAND w/shell Building Pad -3 2 15 1 18.2 95 3 Building Pad -2 2 17.8 1 19.6 96 4 7/3/18 Building Pad -2 2 11.3 1 15.4 93 5 " Building Pad -1.5 2 10.2 1 16.8 94 6 7/5/18 Garage Pad FSG 2 10.1 116.7 94 7 Building Pad FSG 2 8.7 1 17.2 94 8 Building Pad FSG 2 5.9 118.2 95 9 Patio FSG 2 5.6 117.7 95 Notes: *indicates Sand Cone Test; all other tests Nuclear Gauge Method FG = Finished Grade SG = Subgrade TABLE 2 — LABORATORY MAXIMUM DRY DENSITY/ OPTIMUM MOISTURE RELATIONSHIP ASTM D1557-12 Soil Description Optimum Moisture Maximum Dry Type Content (%)y Densit f c (p I Dark grayish -brown Clayey SAND, 9.0 127.0 fine to coarse w/shell fragments 2 Grayish -brown silty SAND w/shell 11.5 124.0 fragments — Cement -Treated R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 TABLE 3 — CHEMICAL TESTS File No: 8154-10 Report No: 20180709-2 Page: 10 A series of chemical tests were performed. The testing was performed by Anaheim Test Labs Inc. and HDR as indicated below. TABLE 4 — EXPANSION INDEX TEST RESULTS (ASTM D4829-1 I a) Sample Location Description Expansion Index Soluble Sulfates Soluble Min. Resistivity Test Soil (ppm) Chlorides (ppm) (ohm -cm) Location Classification pH CA. 417 CA. 422 CA. 643 B-1 SC 6.7 951 886 445 Building Pad SP 9.6 528 944 440 TABLE 4 — EXPANSION INDEX TEST RESULTS (ASTM D4829-1 I a) Sample Location Description Expansion Index Expansion Potential B-1 SC 15 Very low R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: I I REFERENCES I . D. Woolley & Associates, 2017, "Topographic Survey, 3803 Marcus Avenue, Newport Beach, California," APN: 423-075-002," February 27, Scale: I" = 10', Sheet I of 1. 2. Barrows, A. G., 1974, "A Review of the Geology and Earthquake History of the Newport Inglewood Structural Zone, Southern California," California Division of Mines and Geology, Special Report 114. 3. Building Seismic Safety Council, 2004, National Earthquake Hazards Reduction Program (NEHRP) Recommended Provisions for Seismic Regulations for New Buildings and Other Structures (FEMA 450), 2003 Edition, Part 2: Commentary, Washington D.C. 4. California Building Code, 2016 Edition. 5. California Division of Mines and Geology, 1998, "Seismic Hazards Zones Map, Newport Beach Quadrangle". 6. California Divisions of Mines and Geology, 2008, "Guidelines for Evaluating and Mitigating Seismic Hazards in California," Special Publication 117A. 7. City of Newport Beach, Community Development Department, Building Division, 2017, Geotechnical Report Review Checklist, First Review, October 30. 8. City of Newport Beach, Community Development Department, Building Division, 2017, Geotechnical Report Review Checklist, Second Review, Decembers. 9. Department of the Navy, 1982, NAVFAC DM -7.1, Soil Mechanics, Design Manual 7. 1, Naval Facilities Engineering Command. 10. Environmental Geotechnology Laboratory, Inc., 1998, "Report of Geotechnical Investigation, 3915 Marcus Avenue, Newport Beach, California," Project No.: 97-125- 002, January 21. 11. Environmental Geotechnology Laboratory, Inc., 2005, "Report of Geotechnical Engineering Investigation, Proposed New Single Family Residence, 3903 Marcus Avenue, Newport Beach, California," EGL Project No.: 05-257-004EL, October 13. 12. 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). 13. 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. 14. Legg, Mark R., Borrero, Jose C., and Synolakis, Costas E., 2003, "Evaluation of Tsunami Risk to Southern California Coastal Cities," Earthquake Engineering Research Institute (EERI), 2002 NEHRP Professional Fellowship Report, Funded by the Federal Emergency Management Agency (FEMA), January. 15. 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. 16. Morton and Miller, 1981, Geologic Map of Orange County, CDMG Bulletin 204. 17. 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. 18. Morton, D. M., Bovard, Kelly H., and Alvarez, Rachel M., 2004, Preliminary Digital Geological Map of the 30'X 60' Santa Ana Quadrangle, Southern California, Version 2.0, Open -File Report 99-172, Version 2.0 — 2004. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 23, 2018 File No: 8154-10 Report No: 20180709-2 Page: 12 19. 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. 20. 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. 21. R McCarthy Consulting, Inc., 2017, "Geotechnical Investigation, Proposed Residential Construction, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-00, Report No: 201703 1 0-1, March 31. 22. R McCarthy Consulting, Inc., 2017, "Supplemental Geotechnical Review, Existing Seawall Loading, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-01, Report No: 201171003-2, October 3. 23. R McCarthy Consulting, Inc., 2017, "Proposed Gravel Trench, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-01, Report No: 20171 128-1, November 28. 24. R McCarthy Consulting, Inc., 2018, "Response to City Review, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-01, Report No: 20180108-1, January 14. 25. R McCarthy Consulting, Inc., 2018, "Interim Construction Recommendations, Tie -Back Deadman for Seawall, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-10, Report No: 20 180524- 1, May 24. 26. R McCarthy Consulting, Inc., 2018, "Foundation Subgrade Preparation, Tie -Back Deadman for Seawall, 3803 Marcus Avenue, Newport Island, Newport Beach, California", File No: 8154-10, Report No: 20180524-1, May 25. 27. Schmertmann, Dr. John H., 1977, "Guidelines for CPT Performance and Design," prepared for the Federal Highway Administration, U. S. Department of Transportation, FHWA-TS-78-209, February. 28. Seed, Bolton H., and Idriss, I. M., 1974, "A Simplified Procedure for Evaluating Soil Liquefaction Potential," Journal of Soil Mechanics, ASCE, Vol. 97, No. SM9, September, pp. 1249-1273. 29. 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. 30. Terzaghi, Karl, Peck, Ralph B., and Mesri, Ghoamreza, 1996, "Soil Mechanics in Engineering Practice, Third Edition," John Wiley & Sons, Inc. 31. Tokimatsu, K., and Seed, H. B., 1987, "Evaluation of Settlements in Sands Due to Earthquake Shaking," Journal of the Geotechnical Engineering Division, ASCE,1 13(8), pp. 861-878. 32. U. S. Geological Survey, Earthquake Hazards Program, 2014, U. S. Seismic Design Maps, U. S. Department of the Interior, U. S. Geological Survey Page 33. 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. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newpott Beach, CA 92660 e s� L Ln ¢ s� T. F' N 3 Fx¢z n.n eu a= b s� (831VM) 01�V 3AIN U F' N 3 Y �• 'I C .T Y v v 0 CID m o a Fx¢z n.n eu a= b s� (831VM) 01�V 3AIN U N Y C .T Y v v 0 CID m o a U U = w o Z a LL Lu J lJJ a J • i� N I nGr N v m W R M C CARTHY CONSULTING, INC July 24, 2019 (Revised! August 13, 2019) Mr. Scottie Upshall 3803 Marcus Avenue Newport Beach, California 92663 Subject: Earthwork Observation/Testing Report Project Final Report 3803 Marcus Avenue Newport Island Newport Beach, California File No: 8154-10 Report No: R8-8154 Legal Description: Lot 2, Block 338, City of Newport Beach, Map of Canal Section, filed in Book 4, Page 98, of Miscellaneous Maps in the Office of the Orange County Recorder, State of California APN: 423-075-002 Grading :Permit No: 2245-2017 References: 1. R McCarthy Consulting, Inc., 2018, "Earthwork Observation/Testing Report, Proposed Residential Construction, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-10, Report No: 20180709-2, July 23, 2. R McCarthy Consulting, Inc., 2018, "Foundation Subgrade Preparation, Tie -Back Deadman for Seawall, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-10, Report No: 20180524-1, May 25. 3. R McCarthy Consulting, Inc., 2018, "Tie -Back Deadman for Seawall, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-10, Report No: 20180524-1, May 24. 4. R McCarthy Consulting, Inc., 2018, "Response to City Review, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-01, Report No: 20180108-1, January 24. 5. R McCarthy Consulting, Inc., 2017, "Proposed Gravel Trench, 2017, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-01, Report No: 20171128-1, November 28. 6. R McCarthy Consulting, Inc., 2017, "Supplemental Geotechnical Review, Existing Seawall Loading, 3803 Marcus Avenue, Newport Island, Newport Beach, California," File No: 8154-01, Report No: 20171003-2, October 3. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Phone 949 629 2539 1 Email info@rmccarthyconsulting.com July 24, 2019 (Revised August 13, 2019) File No: 8154-10 Report No: R8-8154 Page: 2 7. R McCarthy Consulting, Inc., 2017, "Proposed Residential Construction, 3803 Marcus Avenue, Newport Island, Newport Beach, Califomia," File No: 8154-00, Report No: 20170310-1, March 31. This report presents the results of our observation and testing services performed during the construction phase activities for the property located at 3803 Marcus Avenue on Newport Island in the City of Newport Beach, California. This report was revised to include recent testing of the exterior hardscape subgrade soils, which was performed following removals of portions of the concrete hardscape. We understand that the earthwork is now completed and no further grading or earthwork is to be done. This report may, therefore, be considered to be a final report of our earthwork observation and testing. Based on our observations, and review of the test results, it is our opinion that the earthwork reported herein was performed in substantial conformance with the City of Newport Beach and project grading requirements. PRO]Eci DATA 3803 Marcus Avenue, Lot 2, Block 338 Newport Island, Newport Beach, Califomia Owner: Scottie Upshall General Contractor: Spinnaker Development, Inc. Grading Contractor: Tight Quarters Seawall Contractor: Dallinghaus Civil Engin L. Forkert Engineering, Inc. Regulatory Agency City of Newport Beach Gradin Plans: "Precise Grading Plan, 3803 Marcus Avenue, Newport Beach, CA," prepared by Forkert Engineering and Surveying, Inc., Sheet C-2, November 15, 2017 (latest revision). Geotechnical Observation Penod• May 8, 2018, through August 13, 2019 SITE DESCRIPTION The subject property is located at 3803 Marcus Avenue on the southern side of Newport Island, on the southwest side of Marcus Avenue, and immediately southeast of Newport Island Park. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 24,2019 (Revised August 13, 2019) GRADING AND -E A. General File No: 8154-10 Report No: 118-8154 Page: 3 The observation and testing reported herein is subsequent to the grading reported in Reference 1 and includes the footing excavations, the house and garage slab subgrade preparation. The contractor removed existing poured concrete panels at 2 locations at the site in August 2019 to allow observation and testing of the subgrade soils. The exposed soils were probed and tested as indicated below to check the compaction. Our test results indicated that the exterior hardscape subgrade soils were adequately compacted as further indicated below and in Table 1. .� •1 Fill and backfill material consisted of on-site silty sand, imported sand and gravel. Equipment used for compaction Included hand operated mechanical equipment and a water hose. • Building pad and site grading was observed and tested as previously reported in Reference 1. • Installation and backfill of the deadman and tie -backs was observed and tested as indicated in Reference 1. • Foundation and slab areas for the house structure were observed periodically during the construction and approved from a geotechnical standpoint. • Interior plumbing trenches were backfilled with compacted on-site sand and shading sand. • The sewer trench was backfilled with gravel and compacted with on-site soil. • The water line, electric and gas trenches were backfilled with shading sand and/or on-site soil. • The hardscape subgrades consisted of silty sand and imported gravel. Testing was performed on representative areas to render a professional opinion as to the compaction of fill materials. It is our opinion that sufficient testing was performed to arrive at the conclusions stated herein; however, this is an opinion and is not a warranty that all fill materials are at 90 percent relative compaction. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 24, 2019 (Revised August 13, 2019) VSORMGz a � M • .. .. A. General File No: 8154-10 Report No: R8-8154 Page: 4 Based upon field observations and test results, it is our opinion that grading and compaction described herein was accomplished in accordance with the project requirements and the grading requirements of the City of Newport Beach. Field density testing indicated that a minimum of 90 percent relative compaction was achieved at the locations tested. Based on the observations and testing, the described fill, trench backfill and subgrade soils (including the recently tested exterior hardscape subgrade materials) placed at the site are considered suitable for the intended use. ■- 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. 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 retaining walls, paved walkways, utility installations or other various improvements. Ponded water, incorrect drainage, leaky irrigation systems, overwatering or other conditions should be avoided. C. Subseauent Grading Operations Prior to the commencement any future on-site earthwork, we recommend to the Owner that a geotechnical engineer be notified to provide appropriate recommendations and observation and testing services as required. LIMITATIONS Our description of grading operations, as well as observations and testing, has been limited to those grading operations periodically observed by representatives of R McCarthy Consulting, Inc., between May 8, 2018, and August 13, 2019. This report does not include line and grade survey results. Elevations and locations used in this report are estimated based on field surveys done by others. The opinions rendered apply to conditions in the subject areas observed by us as of the date of our final site visit. We are not responsible for any changes in the conditions that may occur after that date and outside our purview. Our work is considered to be in accordance with the usual standards of the profession and with local practice. No other warranty is expressed or implied. R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 24, 2019 (Revised August 13, 2019) File No: 8154-10 Report No: R8-8154 Page: 5 The opportunity to be of service is appreciated. If you have any questions, please call. Respectfully submitted, R MCCARTHY CONSULTING, INC. Geotechnical Engineer Registration Expires 3-31-20 Date Signed: 7/24/19 Attachments: Table 1 — Results of Field Density Tests Table 2 — Laboratory Maximum Dry Density/Optimum Moisture Relationship References Figure 1, Geotechnical Plot Plan R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 July 24, 2019 File No: 8154-10 (Revised. August 13, 2019) Report No: R8-8154 Page: 6 TABLE i — RESULTS OF FIELD DENSITY TESTS Test No. Test Date Location Elevation (feet) Soil Type Moisture Content (0/0) Dry Density (P� Relative Compaction 1 5/8/18 Building Pad -3.5 2 11.7 116.3 94 2 Grayish -brown Silty SAND with shell Building Pad -3 2 15 118.2 95 3 Building Pad -2 2 17.8 119.6 96 4 7/3/18 Building Pad -2 2 11.3 115.4 93 5 XA Building Pad -1.5 2 10.2 116.8 94 6 7/5/18 Garage Pad FSG 2 10.1 116.7 94 7 Building Pad FSG 2 8.7 117.2 94 8 Building Pad FSG 2 5.9 118.2 95 9 Patio FSG 2 5.6 117.7 95 10* 8/13/19 Hardscape FSG 2 12.1 115,0 91 Notes: *indicates Sand Cone Test; all other tests Nuclear Gauge Method FSG ,= Finished Subgrade SG = Subgrade TABLE 2 — LABORATORY MAXIMUM DRY DENSITY/ OPTIMUM MOISTURE RELATIONSHIP ASTM D1557 Soil Description Optimum Moisture Maximum Dry Type Content (%) Density (pcf) 1 Dark grayish -brown Clayey SAND, 9.0 127.0 fine to coarse with shell fragments 2 Grayish -brown Silty SAND with shell 11.5 124.0 fragments — Cement -Treated R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150, Newport Beach, CA 92660 Wo N C d a a �c c c W 4 J W t0 � z ! a J � ' a W � R M C C.ARTHY —= CONSULTING, INC Field Memorandum Client: Upshall Date: July 30, 2018 Project Address: 3803 Marcus Avenue, Newport Beach Project No. 8154-10 Subject: "()R6eFVAlpi741U stibra'del Stephan Cousineau of R. McCarthy Consulting, Inc., was on-site to observe and document the condition of the slab subgrade. Upon arrival it was noted that the contractor was in the process of placing gravel atop of the slab subgrade soils within the foundations. These subgrade soils were probed and found to be firm and unyielding. The condition of the subgrade soils are in general conformance with the recommendations of this firm and of the approved plans and, as such may be utilized for their intended use. Respectfully submitted, R McCarthy Consulting, Inc. Stephan P. Cousineau R McCarthy Consulting, Inc. 23 Corporate Plaza, Suite 150 Newport Beach, CA 92660 R MCCARTHY CONSULTING,INC FIELD MEMORANDUM CLIENT/ CONTRACTOR: C/O Upshall/ Spinnaker SITE ADDRESS: 3803 Marcus Ave Newport Island, NB Date: 07-18-2018 File No. 8154-10 Activity Footing Excavations Permit No. 2245-2017 ;ite to observe the footing excavations at the subject site on July 18, 2018. Excavations for the footings and e beams exposed competent previously placed cement -treated engineered fill. The exposed soil was probed materials were observed to be firm and competent, probing less than an inch. >ed on our observations, it is our opinion that the subject foundation excavations are in compliance with the eject requirements and our recommendations and, from a geotechnical standpoint, are suitable for placement reinforcing steel and concrete. The excavations should be kept clean of loose soil and debris prior to placing observations do not include line and grade, which we understand is being checked by other parties. IM Rob McCarthy - Engineer Ate 150 1 Newport Beach, CA 92660 info@Rmccarthyconsulting.com