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HomeMy WebLinkAboutX2016-4299 - SoilsJanuary 19, 2018 VaGeos Consulting Engineering Geologists X,2016-42gq 4q Seaward Rd Juan and Orli Estrada Project No. 161503 c/o Free Creation, Inc. Report No. 18-008 5478 Wilshire Blvd., Suite 214 Los Angeles, CA 90036 Subject: Report of Rough Grading and Retaining Wall Backfill 549 Seaward Road Corona del Mar, California COMB Permit: X2016-4299; Project No. 2954-2016 Reference: 1. Rough Grade Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California, by David A. Purkis, PE, dated January 19, 2018, Project No. 16-3728. (See attached report.) 2. Summary of Engineering Geologic Observations, Rough Grading for Garage and Lower Level Building Pads, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated August 3, 2017, Project No. 161503 , Report No. 17-074. 3. Preliminary Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503, Report No. 16-121. Dear Mr. and Mrs. Estrada; This letter and attached report present a summary of engineering geologic observations and geotechnical observations and testing performed during rough grading of the upper level building pads and backfill of garage/lower level retaining walls of the residence under construction at the subject site. Engineering geologic observations reported herein occurred during the period from July, 2017 to January, 2018. Rouah Grading Prior to rough grading, the former residence and site improvements, other than the site retaining wall at the northeasterly property margin, were demolished and debris was removed from the site. Remedial grading performed in conjunction with rough grading of the upper level building pad and rear yard consisted of overexcavation and recompaction of near surface soils. The depth of overexcavation was typically 3± feet below original site grades, 3.5 to 4± feet below upper level building pad grades. The maximum fill thickness is about 4 feet at locations along the southwesterly side of the upper level building pad. Firm native soils (terrace deposits) were exposed in removal bottoms at locations of engineered fill placement. Approximate removal bottom elevations and limits of engineered fill are depicted on Plate 1 of the attached report by David A. Purkis, PE. ViaGeos* 305 N. Coast Highway, Suite R TEL (949) 494-2721 P.O. Box 309, Laguna Beach, CA 92652 FAX (949) 376-5766 549 Seaward Road January 19, 2018 Corona del Mar, California Project No. 161503 Report No. 18-008 Rough grading of the garage/lower level building pads included excavation and export of native soils (terrace deposits) to construct the building pads. The excavation bottom exposed competent terrace deposits that consist of dense silty sand. A summary of engineering geologic observations documented during rough grading of the garage/lower level building pads were presented in Reference 2. Retainina Wall Subdrain and Backfill Burrito style subdrains were constructed around the perimeter of the garage/lower level retaining walls. Subdrains consist of 4 -inch perforated drain pipe surrounded by clean gravel and all enclosed within a geotextile filter fabric. Miradrain panels were placed against the retaining walls are in contact with the burrito style subdrain. Backfill around the garage/lower level retaining walls consists of compacted on-site sandy soils. On the northwesterly and southwesterly sides of the garage/lower level retaining walls, the upper 2 feet of backfill that supports adjacent footings of the upper level was compacted with a minimum compaction standard of 95 percent relative compaction. Geotechnical observations and testing performed during retaining wall backfill operations are presented in the attached report by David A. Purkis, PE. Conclusions Soil conditions encountered during rough grading of the site, including retaining wall backfill operations performed to date, are consistent with those described in Reference 3 and no additional recommendations are provided at this time. The site is considered acceptable, from an engineering geologic viewpoint, for construction of the upper level foundations and slabs. Closure Our observations have been performed using the degree of care and skill ordinarily exercised under similar circumstances by reputable engineering geologists and geotechnical consultants practicing in this or similar locales. No warranty, expressed or implied, is made as to the conclusions and professional advice provided herein. The conclusions of this report are based on limited site observations by this office and others during grading. The opport ' y to be of service is appreciated. Please call this office if you have any questio , c ments or require any additional information. /Scerel o U5\GZrEt. EP GEI NL ERIRTifil-DG is el . Childs, President k, pc t gineering Geologist EG 1664 — Registration Expires 3/31 /18 Attachement: Rough Grade Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California, by David A. Purkis, PE, dated January 19, 2018, Project No. 16-3728. ViaGeos DAVID A. PURKIS, PE Consulting Civil Engineer January 19,2018 Project No.: 16-3728 T0: Juan and Orli Estrada c/o ViaGeos 305 North Coast Highway, Suite R Laguna Beach, CA 92651 SUBJECT: Rough Grade Compaction Report Residential Development 549 Seaward Road, Corona del Mar, California REFERENCE: 1. ViaGeos, December 12, 2106; "Preliminary Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California" 2. Duca-McCoy, Inc., December 14,2016; "Grading Plan of 549 Seaward Road, Corona del Mar, CA, Lot 105 of Tract No. 1237" INTRODUCTION In conjunction with ViaGeos, we have provided geotechnical services during rough grading of the subject site. The services included observation and testing during grading and wall backfill activities between July 2017 and January 2018. A copy of Reference 2 was used herein to record pertinent geotechnical data and is attached as Plate 1. Accompanying Illustrations and Appendices Appendix A - Summary of Field Density Tests Appendix B - Laboratory Tests and Procedures Plate 1 — Geotechnical Plot Plan GRADING SUMMARY The grading of the subject site consisted of over -excavation and recompaction of existing surficial soils in accordance with the recommendations of Reference 1 and backfill of the garage retaining walls. The approximate limits and depths of fill placement are depicted on Plate 1. 32158 Camino Capistrano #212, San Juan Capistrano, CA 92675 • 949.240.7293 • fax 949.454.0927 Estrada - Rough Grading January 19, 2018 Page 2 Excavation and compaction of fill materials was accomplished with a Caterpillar 268B skidsteer loader and hand operated mechanical compactors. The contractors were SGE Excavation and FreeCreation Contracting. The fill was placed in approximately 8 -inch loose lift thicknesses. Water was added with a hose. Consolidation of fill materials was accomplished by repeated passes with the aforementioned equipment. FIELDAND_LABORATORY = TESTING The compaction standard used for the minimum density requirements was 90 percent of ASTM D-1557 Test Method. Field densities were obtained in accordance with ASTM D- 1556 (Sand Cone) Test Method. A total of 12 relative compaction tests were taken at the subject site. These tests are numbered and the approximate locations are shown on the accompanying Plate 1. The results of the field density and laboratory tests are summarized in Appendix A and B, respectively. Testing was performed in representative areas in order to provide a professional opinion as to the compaction of the fill materials. This is not a warranty that all fill soils have a relative density of at least 90 percent of maximum. CONCLUSIONS 1. Removal of Unsuitable Materials Unsuitable soil materials were removed from the graded areas to the approximate limits and depths depicted on Plate 1. The project geologist observed the over - excavation bottoms prior to placement of fill. 2. Compaction The results of tests and observations indicate that the fill soils placed during rough grading have been compacted to minimum requirements to the approximate depths and limits indicated on the attached Plate 1 in accordance with the project specifications. 3. Rough Grade Conclusion Rough Grading is appropriate for the intended use and is approved for those portions of the subject building area as delineated on the accompanying map from Estrada - Rough Grading " January 19, 2018 Page 3 a soil engineering viewpoint provided the geotechnical recommendations from Reference 1 are implemented. RECOMMENDATIONS 1. Geotechnical Recommendations The geotechnical recommendations presented in the Reference 1 remain appropriate for foundation design. 2. Fine Grading All fine grading should be accomplished so that water is directed away from footings and slabs. No water should be allowed to pond adjacent to footings and slabs. 3. Observations and Tests The Soils Engineer or Engineering Geologist should perform observations and tests at the following stages: A. After footing excavations for the structure foundation, but prior to placement of steel. B. During any additional retaining wall backfill and any trench backfill operation. C. During subgrade preparation and base placement for exterior hardscape areas. 4. Maintenance Throughout the life the of the project, regular site maintenance should be conducted to ensure that drainage components are clean of obstructions and that they properly control surface waters in accordance with the recommendations of the referenced report. Landscaping installations should be maintained in a manner that does not allow water to pond near sloped areas or in areas adjacent to structures. Estrada - Rough Grading January 19, 2018 Page 4 CLOSURE This work was conducted in accordance with generally accepted practice in the soils engineering field. No other warranty is offered or implied. The conclusions and recommendations presented in this report are based on surface and subsurface conditions encountered and the present state of geologic knowledge. They are not intended to imply a control of nature. As site geotechnical conditions may alter with time, the recommendations presented in this report are considered valid for a period of one year from_the-report_ date. Changes in the proposed land use or development may require supplemental investigations or recommendations. Lastly, independent use of this report in any form cannot be approved unless specific, written verification of the applicability of the recommendations is obtained from this office. Thank you for the opportunity to be of service. If you have any questions, please call. Respectfully Submitted, David A. Purkis Civil Engineer (RCE 42810) Expires 3/31/18 No. 42810 Exp: 3-31-18 APPENDIX A - SUMMARY OF FIELD DENSITY TESTS TEST TEST TEST APPROX. SOIL DRY DENSITY MOISTURE RELATIVE NO. DATE LOCATION ELEV. TYPE FIELD MAX. FIELD OPT. COMPACT pcf pcf % % % 1 7/14/17 Fill 106.8 1. 117.1 123.0 13.1 11.0 95 2 7/17/17 Fill 107.5 1 115.1 123.0 13.3 11.0 94 3 7/18/17 Fill 108.0 1 114.4 123.0 13.6 11.0 93 4 7/18/17 Fill 108.8 1 113.3 123.0 13.6 11.0 92 5 11/10/17 RW 102.0 1 116.4 123.0. 14.1 11.0 95 6 11/15/17 RW 103.0 1 117.6 123.0 14.3 11.0 96 7 11/20/17 RW 104.2 1 113.3 123.0 13.5 11.0 92 8 11/28/17 RW 105.2 1 112.9 123.0 13.3 11.0 92 9 12/1/17 RW 106.5. 1 115.7 123.0 13.8 11.0 94 10 12/8/17 RW 108.4 1 116.8 123.0 14.1 11.0 95 11 12/8/17 RW 108.4 1 120.0 123.0 13.9 11.0 98 12 1/18/18 RW 109.0 1 114.5 123.0 13.2 11.0 93 Tests taken by sand cone method ASTM D-1556. APPENDIX B - LABORATORY DATA PROJECT: Estrada Project No. 16-3728 549 Seaward Road Corona Del Mar, Ca A. Maximum Density -Optimum Moisture Determination Maximum density and optimum moisture content were determined in accordance with Test Designation ASTM D 1557-07. The test results are summarized below. Sample Location Material Type Optimum Moisture. Max. Dry Density PCF As provided Brown silty sand/sandy silt 11.0 123.0 N_ O C O a�nC- �J f August 3, 2017 Juan and Orli Estrada c/o Free Creation, Inc. 5478 Wilshire Blvd., Suite 214 Los Angeles, CA 90036 V aGeos Consulting Engineering Geologists Project No. 161503 Report No. 17-074 Subject: Summary of Engineering Geologic Observations Rough Grading for Garage and Lower Level Building Pads 200 Poppy Avenue Corona del Mar, California COMB Permit: X2016-4299; Project No. 2954-2016 Reference: 1. Preliminary Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503, Report No. 16-121. 2. Grading Plan of 549 Seaward Road, Corona del Mar, CA, Lot 105 of Tract 1237, by Duca-McCoy, Inc. Dear Mr. and Mrs. Estrada ; This letter presents a summary of engineering geologic observations during rough grading of the garage and lower level building pad for the proposed residence at the subject site. Engineering geologic observations reported herein occurred during the period from July 20, 2016 to July 26, 2017. Rough Grading Rough grading of the basement level building pad was performed by.... Rough grading included excavation and export of native soils to construct the building pad. The excavation bottom exposes competent native soils (terrace deposit) that consist of dense to slightly silty sand. Temporary construction excavations (retaining wall back cuts) around the perimeter of the lower level excavation expose competent terrace deposits and geotechnically approved compacted fill, and have been laid back in general accordance with the recommendations provided in Reference 1. Remedial grading of the upper building pads has been partially completed and additional rough grading of the upper pad and rear yard hardscape areas will be performed following construction and backfill of the foundation retaining walls that will separate lower and upper building pads. Conclusions Soil/geologic conditions encountered during shoring construction and grading/excavation for the basement level are generally consistent with those described in Reference 1. The site is considered acceptable, from an engineering geologic viewpoint, for construction of the garage and lower level foundation. ViaGeos* 305 N. Coast Highway, Suite R TEL (949) 494-2721 P.O. Box 309, Laguna Beach, CA 92652 FAX (949) 376-5766 549 Seaward Road Corona del Mar, California August 3, 2017 Project No. 161503 Report No. 17-074 A geotechnical compaction report summarizing geotechnical observations, field density testing and laboratory testing performed during rough grading will be provided at the completion of retaining wall backfill operations and construction of the upper level building pads/site grades. Closure Our observations have been performed using the degree of care and skill ordinarily exercised under similar circumstances by reputable engineering geologists and geotechnical consultants practicing in This or similar locales. No warranty, expressed or implied, is made as -to the conclusions -and-prof essional advice provided herein. =The conclusions of this report are based on limited site observations by this office and others during grading. The op ortumty to be of service is appreciated. Please call this office if you have any qu7eff, hs, comments or require any additional information. Zrely, '_pED �Fo �5 1,EL B. cy U \v� G� No. 1664 �O (n CERTIFIED N ichael B. Childs, President -i ENGINLLEE9CRING N E P, ;Sg Engineering Geologist EG 1664 Registration Expires 3/31 /18 9T P 40 W R� V aGeos ViaGeos Consulting Engineering Geologists FIELD MEMORANDUM Client: Estrada c/o Free Creation, Inc. Date: December 14, 2017 Job Address: 549 Seaward Rd., CdM Subject: Footing excavations- Light well and upper level foundations adjacent to retaining walls Reference: Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by VIaGeos, dated December 12, 2016, Project No. 161503 , Report No. 16- 121. Observations Footing excavations for the light well and upper level foundations located immediately adjacent to the foundation retaining walls of the lower level (on the sides of the residence) have been formed onto firm, unyielding soils (engineered fill) that consist of densely compacted slightly silty to silty sand. Density test results documented by field representative for David A. Purkis, PE indicate at least 90 percent relative compaction of (ower backfill soils and at least 95 percent relative compaction of upper backfill soils within 2 feet of bottom of footings for upper level foundations located immediately adjacent to retaining walls. The approximate locations of observed footing excavations pertinent to this field memorandum are shown on the attached portion of the Basement Framing Plan Foundation Plan, Sheet S-2, by FMH Engineering. (See reverse side.) Conclusions The footing excavations are acceptable, from an engineering geologic viewpoint, for placement of steel and concrete. Recommendations Dimensions and details to be verified by others. Note: This memorandum is not intended to verify footing geometry, steel reinforcing, or that the bottom of the excavations are clean at the time concrete is poured. 305 N. Coast Highway, Suite R Laguna Beach, CA 92651 TEL (949) 494-2721 FAX(949) 376-5766 R- c�j ..€a IJ hin$ � locations of observed footing excavations pertinent to ViaGeos ndum dated Dec. 14, 2017 are shown above as, highlighted areas. 6��2:$ '', SSSSS R- c�j ..€a IJ hin$ � locations of observed footing excavations pertinent to ViaGeos ndum dated Dec. 14, 2017 are shown above as, highlighted areas. ViaGeos Consulting Engineering Geologists FIELD MEMORANDUM Client: Estrada c/o Free Creation, Inc. Date: November 2. 2017 Job Address: 549 Seaward Rd., CdM Subject: Observation of subdrain at basement/garage foundation retaining walls Reference: Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503 , Report No. 16- 121. Observations A retaining wall subdrain has been constructed at the base of the perimeter foundation retaining walls of the basement and garage level. The subdrain consists of perforated 4 -inch drain pipe surrounded by gravel and all enclosed within a geotextile filter fabric. Approximate locations of observed retaining wall subdrain pertinent to this field memorandum are shown on the attached portion of the Basement Foundation Plan, Sheet S-1, by FMH Engineering. (See reverse side.) Conclusions The retaining wall subdrain is suitable for the intended use. Recommendations Waterproofing to be verified by others. Retaining wall backfill may consist of compacted clean gravel, native or imported sandy soils. Where used as backfill, gavel should be mechanically compacted in 2± ft. thick lifts using Whackers or other compaction equipment to consolidate gravel backfill materials, as verified by ViaGeos. A layer of geotextile filter fabric should be placed between the gravel and overlying soil backfill. Soil backfill should be moisture conditioned prior to placement and should be mechanically compacted in lifts to more than 12 inches thick (uncompacted thickness). Compaction testing of soil backfill by the Soil Engineer's re s/entative is required, and testing shall occur at vertical intervals not greater than 2 feet. W / No. 1664 ' CERTIFIED ENGINEERING -Note; Observations presented on this field 1i , subdrain outlet pipes, or waterproofing of relptl taiQir retaining walls and does not constitute an element 305 N. Coast Highway, Suite R Laguna Beach, CA 92651 t intended to verify plumbing and routing of subdrains, subdrain is intended to limit hydrostatic forces behind TEL (949) 494-2721 FAX(949) 376-5766 aeos V aGeos Consulting Engineering Geologists FIELD MEMORANDUM Client: Estrada c/o Free Creation, Inc. Date: October 11, 2017 Job Address: 549 Seaward Rd., CdM Subject: Garage and basement level slab sub , ry ade Reference: Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503 , Report No. 16- 121. Observations Slab subgrade at the garage and basement levels expose firm, unyielding soils (marine terrace deposits) that consist of dense slightly silty to silty sand. A very shallow plumbing trench in the lower level building pad has been backfill with moisture conditioned native sandy soils and tamped to a firm, unyielding condition. Other plumbing pipes that are expose will be surrounded by clean gravel backfill needed to raise the pad grade 6+ inches. Approximate locations of observed slab subgrade pertinent to this field memorandum are shown on the attached portion of the Basement Foundation Plan, Sheet S- 1, by FMH Engineering. (See reverse side.) Conclusions The slab subgrade areas are acceptable, from an engineering geologic viewpoint, for placement of gravel, vapor retarder, sand steel and concrete. Recommendations Subsiab section, vapor retarder, steel reinforcement and slab thickness to be verified by others. .C,`���L BuJ . c\ � 6 No 1664 CER�IEJED ENGINEERING By: is a B. Childs EG 1664 GEoko4! " Note: This memorandum is not intended to verify gravel section, vapor retarder, steel reinforcing, or thickness of concrete floor slabs. 305 N. Coast Highway, Suite R TEL (949) 494-2721 Laguna Beach, CA 92651 FAX(949) 376-5766 Approximate locations of observed slab subgrade pertinent to ViaGeos Field Memorandum dated Oct. 11, 2017 are shown above as highlighted areas. 2 ViaGeos Consulting Engineering Geologists FIELD MEMORANDUM Client: Estrada c/o Free Creation, Inc. Date: August 10, 2017 Job Address: 549 Seaward Rd., CdM Subject: Footing excavations- Garage and basement level foundations Reference: Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503 , Report No. 16- 121. Observations Footing excavations for the garage and basement level foundations have been constructed into firm, unyielding soils (marine terrace deposits) that consist of dense slightly silty to silty sand. Approximate locations of observed footing excavations pertinent to this field memorandum are shown on the attached portion of the Basement Foundation Plan, Sheet S-1, by FMH Engineering. (See reverse side.) Conclusions The footing excavations are acceptable, from an engineering geologic viewpoint, for placement of steel and concrete. Recommendations Dimensions and details to be verified by others. GE No. 1664 CERDOE0 ENGINEERING Note: This memorandum is not intended to verify footing geometry, steel reinforcing, or that the bottom of the excavations are clean at the time concrete is poured. 305 N. Coast Highway, Suite R TEL (949) 494-2721 Laguna Beach, CA 92651 FAX(9A9) 376-5766 ons of observed footing excavations pertinent to Vi*Geos dated Aug. 10, 2017 are shown above as,'highlighte areas. September 4, 2019 Juan and Orli Estrada c/o Free Creation, Inc. 5478 Wilshire Blvd., Suite 214 Los Angeles, CA 90036 Subject: Final Report of Geotechnical 549 Seaward Road Corona del Mar, California COMB Permit: X2016-4299 V aGeos Consulting Engineering Geologists Project No. 161503 Report No. 19-066 Observation and Testing for New Residence Reference: 1. Report of Rough Grading and Retaining Wall Backfill, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated January 19, 2018, Project No. 161503, Report No. 18-008. 2. Rough Grade Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California, by David A. Purkis, PE, dated January 19, 2018, Project No. 16-3728. 3. Summary of Engineering Geologic Observations, Rough Grading for Garage and Lower Level Building Pads, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated August 3, 2017, Project No. 161503, Report No. 17-074. 4. Preliminary Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated December 12, 2016, Project No. 161503, Report No. 16-121. Dear Mr. and Mrs. Estrada, This letter presents a summary of engineering geologic/geotechnical observations performed by ViaGeos, subsequent to rough grading of building pads and backfill of foundation retaining walls, during construction of the residence at the subject site, as required for submittal to the City of Newport Beach. The project builder, at their discretion, made requests for geotechnical observations during course of construction. Rough grading of the garage/ lower level building pad and upper level building pads was completed in January, 2018 and geologic/geotechnical observations and testing are reported in References 1, 2 and 3. Engineering geologic/geotechnical observations reported herein occurred at various stages of construction during the period from January, 2018 to February, 2019, and these included observation of footing excavations for the upper level foundation of the residence, observation of subslab preparation at the upper level, observation of footing excavations for site walls and observation of the swimming pool excavation. A review of current site conditions was performed on September 3, 2019. ViaGeos* 305 N. Coast Highway, Suite R TEL (949) 494-2721 P.O. Box 309, Laguna Beach, CA 92652 FAX (949) 376-5766 549 Seaward Road Corona del Mar, California Foundation Excavations September 4, 2019 Project No. 161503 Report No. 19-066 Footing excavations reviewed during construction included foundations for the residence and site walls in the front and rear yard. Footing excavations for the lower level foundation of the residence were constructed into competent terrace deposits, and footing excavations for the upper level foundation were constructed into engineered fill placed during rough grading and retaining wall backfill operations. (See References 1, 2 and 3.) The footing excavations for site walls located in the front yard were constructed into competent terrace deposits and footing excavation for the low site wall at the perimeter of the rear patio slab was constructed into engineered fill placed during rough grading. Footing excavations reviewed by ViaGeos were documented in field memoranda that were provided to the project builder and City of Newport Beach at the time of construction. Interior Plumbing Trench Backfill and Subslab Preparation Shallow interior pluming trenches were backfilled with compacted on-site soils, and disturbed near surface soils were compacted in preparation for construction of floor slabs. Swimmina Pool Excavation The swimming pool excavation was constructed into competent terrace deposits and engineered fill placed during rough grading. Exclusions Certain earthwork construction at the site was not observed by ViaGeos, and this specifically includes, but is not limited to: retaining wall subdrains for site walls in the front and rear yards (where applicable), backfill of site walls in the front and rear yards. Additional earthwork construction at the site that was not observed by ViaGeos specifically includes sewer and utility trench backfills and compaction of soils placed during preparation of final hardscape subgrades (where applicable). This and other earthwork construction not specifically identified in the preceding paragraphs and prior reports (References 1, 2 and3) were not observed by ViaGeos or David A. Purkis, PE are not a part of this report. Waterproofing of retaining walls, as well as, routing and plumbing of subdrains and subdrain outlet pipes, are not/were not within the purview of engineering geologic and geotechnical observations. Conclusions Engineering geologic and geotechnical observations and testing reported herein indicate the reviewed earthwork construction summarized above and described in our prior reports (References 1, 2 and 3) was performed in general accordance with the recommendations of ViaGeos and is considered adequate for the intended use. Closure Review and approval of the site surface drainage system for compliance with approved plans and verification of proper and effective function is referred to others. Drainage patterns approved by the Civil Engineer and/or Building/Grading Official must be maintained throughout the life of the project. Regular site maintenance must be conducted by the homeowners or their agents to verify that drainage components are clean of obstructions and that they properly and effectively collect and control surface waters. ViaGeos 2 549 Seaward Road September 4, 2019 Corona del Mar, California Project No. 161503 Report No. 19-066 The homeowners should recognize that alteration of drainage patterns, the addition of hardscape elements, changes in landscaping, excessive irrigation and/or seasonal climatic variations may all have an affect on subsurface moisture conditions which in turn may affect structural performance. Slope and site maintenance guidelines are attached in Appendix A. Our observations and testing have been performed using the degree of care and skill ordinarily exercised under similar circumstances by reputable geotechnical consultants practicing in this or similar locales. No warranty, expressed or implied, is made as to the conclusions and professional advice provided herein. The conclusions of this report are based on limited site observations by this office during construction. They are not intended to imply a control of construction practices or of nature. As geotechnical conditions may alter with time, the conclusions of this report are valid as of this date only. Lastly, this report has been prepared to satisfy City of Newport Beach building requirements. The opportunity to be of service is genuinely appreciated. If you have any questions or comments, please contact this office. Sincerely, ViaGeos Michael B. Childs, President Engineering Geologist EG 1664 License Expires 03/31/20 Attachment: Appendix A -Guidelines for General Site and Slope Maintenance ViaGeos 549 Seaward Road Corona del Mar, California Appendix A September 4, 2019 Project No. 161503 Report No. 19-066 GUIDELINES FOR GENERAL SITE AND SLOPE MAINTENANCE Proper maintenance of a property including building pads and slopes is crucial to its long- term structural performance, upon which residences depend. The following guidelines are presented to aid the homeowner in properly caring for building pads and slopes, and thereby help maintain the structural integrity of their homes: I. Most earth materials are moisture -sensitive and uncontrolled water is often a major cause of deterioration of a property. Sources of water may include irrigation, rainfall, leaking pipes, and natural groundwater. Ideally, moisture conditions beneath all structural elements such as foundations and slabs and beneath slopes should be carefully controlled to provide a constant and uniform soil moisture throughout the year. Variations in moisture content in subsurface soils may be minimized through proper landscape and hardscape design and maintenance. Subsurface moisture conditions are affected by variations in irrigation water volumes, seasonal rainfall, landscaping or placement of impermeable coverings such as slabs, steps, walkways and sealed planters. Homeowners should try to integrate and balance these elements in conjunction with drainage devices to maintain a constant uniform subsurface moisture condition beneath all foundations and slopes throughout the year. a) All water derived from surface runoff should be directed away from foundations and slopes. Finish grades should be properly constructed and maintained across the property so that surface sheetflow runoff from irrigation or rainfall is drained in a non-erosive manner away from foundations and slopes, and water should not be allowed to erode, pond and percolate into the ground adjacent to structures or into slopes. The drainage patterns approved at the time of fine grading, including earth berms, should be maintained throughout the life of the project. b) Roof drain runoff should be diverted by sidewalks, driveways, aprons or ground gutters away from earthen areas and collected by surface drain inlets and solid pipes and flow offsite to a proper outlet. c) All gutters, drains, catch basins and drainage courses should be kept clean and unclogged to allow proper drainage and collection. Drainage systems should be periodically inspected prior to and during periods of heavy rains. d) Homeowners should be attentive to records of water usage. Unusually high usage may indicate leaking water lines. Persistent damp ground, slabs or walls, or musty odors may be another indication of leaking pipes. Any indication of leaking water, sewer or drain pipes should be investigated immediately by a competent plumber experienced in detecting leaks. e) Subdrains behind retaining walls and beneath fill slopes, which help to control the flow of groundwater, should be checked periodically to assure they are clean and perform properly. VlaGeos 4 549 Seaward Road September 4, 2019 Corona del Mar, California Project No. 161503 Report No. 19-066 II. Proper landscaping and proper design and construction of hardscape elements is a very important aspect of maintaining site stability. a) Slopes should be properly planted and irrigated. Drought resistant plants are recommended to help prevent the possibility of over -watering. A landscape expert should be consulted when designing or changing the landscaping and irrigation of a residence. b) A combination of shallow -rooted groundcover and deep-rooted shrubs and trees planted in moderation may help to reduce erosion during rainy periods or due to irrigation and help maintain surficial stability of slopes. Heavy groundcover requiring extensive irrigation should be avoided. c) Fill placement for landscaping elements, terraces or slopes, or construction of hardscape devices such as planters, walkways, patios and steps should avoid altering flow patterns designed for proper drainage of the site. The property owners should recognize that alteration of drainage and landscaping patterns, or the addition of hardscape elements may create water problems that could affect structural performance. III. Rodent activity should be controlled, and animal burrows that may act as a conduit for water and soften or erode the slope should be filled. IV. Slopes and grades approved during fine grading of the property should not be altered without expert consultation. ViaGeos VaGeos Consulting Engineering Geologists September 20, 2019 Juan and Orli Estrada c/o Free Creation, Inc. 5478 Wilshire Blvd., Suite 214 Los Angeles, CA 90036 Subject: Addendum to Final Report of Geotechnical Observation and Testing for New Residence 549 Seaward Road Corona del Mar, California COMB Permit: X2016-4299 Project No. 161503 Report No. 19-075 Reference: 1. Final Report of Geotechnical Observation and Testing for New Residence, 549 Seaward Road, Corona del Mar, California, by ViaGeos, dated September 4, 2019, Project No. 161503, Report No. 18-066. 2. Supplemental Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California, by David A. Purkis, PE, dated September 20, 2019, Project No. 16-3728. Dear Mr. and Mrs. Estrada, This addendum to our Final Report of Geotechnical Observation and Testing for New Residence (Reference 1) presents a summary of additional engineering geologic/geotechnical observations and testing performed by ViaGeos and David A. Purkis, PE to address retaining wall subdrains and retaining wall backfill conditions that were excluded from our prior final report, as such additional information was requested by the City of Newport Beach. Additional observations and testing pertain to retaining wall subdrains and backfill conditions at the front of the site that were not observed and tested during the course of construction because this office was not notified of the earthwork construction activities at the time such work was performed. In order to verify retaining wall subdrains and retaining wall backfill conditions, excavations were provided by the project builder to allow observation of subgrade conditions. At the location of the retaining wall along the southwesterly side of the front patio, the exposed subdrain was observed to be inadequate. The retaining wall backfill was removed from this location and a subdrain was installed near the base of the retaining wall. The burrito style subdrain consists of a perforated 4 -inch drain pipe surrounded by gravel and all enclosed in a geotextile filter fabric. The wall was subsequently backfilled with compacted sandy native soils. Geotechnical observations and testing during retaining wall backfill operations are presented in the attached report by David A. Puriks, PE. The approximate location of the retaining wall subdrain and limits of geotechnically reviewed retaining wail backfill are shown on Plate 1 of that report. ViaGeos* 305 N. Coast Highway, Suite R TEL (949) 494-2721 P.O. Box 309, Laguna Beach, CA 92652 FAX (949) 376-5766 549 Seaward Road Septmber 20, 2019 Corona del Mu, California Project No. 161503 Report No. 19-075 At the front, northeasterly side of the property, retaining wall subdrain components were observed at the front of the house foundation retaining wall, but no subdrain could be exposed for the adjacent site wall that supports grade for the walkway along the property margin because this area is paved with concrete. To provide measures to relieve potential hydrostatic loading on this retaining wall, weep holes were drilled into the base of the retaining wall and a retaining wall subdrain was provided in contact with the weep holes within the bottom of the adjacent raised planter. A previously constructed subdrain at this location was considered inadequate. The new burrito style subdrain consists of a perforated 4 -inch drain pipe surrounded by gravel and all enclosed in a geotextile filter fabric. The approximate location of the retaining wall subdrain is shown on Plate 1 of the attached report. The retaining wall backfill exposed in an exploratory excavation was observed to be firm and unyielding, and the retaining wall backfill that occurs beneath concrete walkway on the front, northeasterly side of the property is considered to be adequately compacted. (See attached report by David A. Purkis, PE.) Based upon further observation of site conditions and review of prior construction documentation, there is no need for a subdrain at the perimeter edge of the concrete patio in the rear yard, and the patio subgrade is considered adequate for the intended use. Conclusions Based on additional engineering geologic and geotechnical observations and testing reported herein, the reviewed earthwork construction at the front of the property that is summarized above was performed in general accordance with the recommendations of ViaGeos and is considered adequate for the intended use. Closure Our observations and testing have been performed using the degree of care and skill ordinarily exercised under similar circumstances by reputable geotechnical consultants practicing in this or similar locales. No warranty, expressed or implied, is made as to the conclusions and professional advice provided herein. The conclusions of this report are based on limited site observations by this office during construction. They are not intended to imply a control of construction practices or of nature. As geotechnical conditions may alter with time, the conclusions of this report are valid as of this date only. Lastly, this report has been prepared to satisfy City of Newport Beach building requirements. The oppattunity to be of service is genuinely appreciated. If you have any questions or comments, please contact this office. i Sincerely, %a o ��m S Mo. 7uo4 O �1f CCR �--'� EMGI�IEEP.If`1G Migg el B. Childs, President �T E PES ice// J CEngineering Geologist EG 1664 Vn oR�� License Expires 03/31 /20 ` y �CA� Attachment: Supplemental Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California, by David A. Purkis, PE, dated September 20, 2019, Project No. 16-3728. DAVID A. PURKIS, PE Consulting Civil Engineer September 20, 2019 Project No.: 16-3728 TO: Juan and Orli Estrada c/o ViaGeos 305 North Coast Highway, Suite R Laguna Beach, CA 92651 SUBJECT: Supplemental Compaction Report Residential Development 549 Seaward Road, Corona del Mar, California REFERENCE: 1. ViaGeos, September 4, 2019; "Final Report of Geotechnical Observation and Testing for New Residence, 549 Seaward Road, Corona del Mar, California, COMB Permit:X2016-4299" 2. David A. Purkis, PE, January 19, 2018; "Rough Grade Compaction Report, Residential Development, 549 Seaward Road, Corona del Mar, California 3. ViaGeos, December 12, 2106; "Preliminary Geotechnical Investigation for Proposed Residence, 549 Seaward Road, Corona del Mar. California" INTRODUCTION Based on requirements from City Building Inspection, we have conducted a review of the as -built conditions at the subject site. The review included observations of subgrade conditions, where exposed in exploratory excavations; observation and testing of backfill placed behind the southeasterly retaining wall near to the southerly property margin and consultation with the project geologist. Accom going Illustrations and Appendices Appendix A - Summary of Field Density Tests Appendix B Laboratory Tests and Procedures Plate 1 — Geotechnical Plot Plan GRADING SUMMARY Testing of fill placement during rough grading is reported in Reference 2 and included backfill of the garage retaining walls and preparation of the upper building pad. Fill placement subsequent to rough grading was limited in scope. Limited exposure of fill placed for the stairs on the northeasterly portion of the lot was observed during removal of dirt from the planter box in front of this area. The exposed soil appeared to be dense 32158 Camino Capistrano #212, San Juan Capistrano, CA 92675 - 949.240.7293 • fax 949.454.0927 Estrada - Supplemental September 20, 2019 Page 2 and well compacted. Approximately 2 feet of fill was placed behind the retaining wall on the southeasterly portion of the lot following the installation of an additional subdrain. The fill was compacted with a hand operated mechanical compactor (Wacker). Water was added with a hose. FIELD AND LABORATORY TESTING The compaction standard used for the minimum density requirements was 90 percent of ASTM D-1557 Test Method. Field densities were obtained in accordance with ASTM D-1556 (Sand Cone) Test Method. A total of 1 relative compaction test was taken for this supplemental evaluation. The test is included in a summary of all the tests taken for the project in Appendix A and its approximate location is depicted on the accompanying Plate 1. The results of laboratory tests are summarized in B. Testing was performed in representative areas in order to provide a professional opinion as to the compaction of the fill materials. This is not a warranty that all fill soils have a relative density of at least 90 percent of maximum. EXCLUSIONS The project principles/contractors, at their discretion, made requests for geotechnical observations and tests. This report is limited to the items specifically described herein as having been observed or tested. Items not observed by the geotechnical consultants are excluded from this report. CONCLUSIONS 1. Building Foundation Soils and Garage Wall Backfill The results of tests and observations indicate that the fill soils placed during rough grading were compacted to minimum requirements to the approximate depths and limits indicated on the attached Plate 1 in accordance with the project specifications. 2. Subgrade Fills Based on limited observation and descriptions of work performed, the small amounts of subgrade fills appear to be suitable for their intended use. 3. Compaction The results of tests and observations indicate that observed fill soils placed during project development have been compacted to minimum requirements to the Estrada - Supplemental September 20, 2019 Page 3 approximate depths and limits indicated on the attached Plate 1 in accordance with the project specifications. 4. Conclusion Observations and testing conducted during project development indicate that the fill placement observed is in general accordance with the geotechnical recommendations and are adequate for their intended use from a geotechnical viewpoint. CLOSURE This work was conducted in accordance with generally accepted practice in the soils engineering field. No other warranty is offered or implied. The conclusions and recommendations presented in this report are based on surface and subsurface conditions encountered and the present state of geologic knowledge. They are not intended to imply a control of nature. As site geotechnical conditions may alter with time, the recommendations presented in this report are considered valid for a period of one year from the report date. Changes in the proposed land use or development may require supplemental investigations or recommendations. Lastly, independent use of this report in any form cannot be approved unless specific, written verification of the applicability of the recommendations is obtained from this office. Thank you for the opportunity to be of service, if you have any questions, please call. Respectfully Submitted, ✓ � C'` David A. Purkis Civil Engineer (RCE 42810) Expires 3/31/20 No. 42810 Exp: 3.31.20 Appendix A - Summary of Field Density Tests Projecc Estrada 359 Seaward Proj #i 372'8 TEST TEST TEST APPROX.. SOIL DRY DENSITY - MOISTURE RELATIVE NO. DATE LOCATION ELEV. TYPE FIELD MAX. FIELD OPT. COMPACT pcf Pcf % % % 1 7/14/17 Flt 106.8 1 117.1 123.0 13.1 11.0 95 2 7/17/17 Fill 107.5 1 115.1 123.0 13.3 11.0 94 3 7/18/17 Fill 108.0 1 114.4 123.0 13.6 11.0 93 4 7/18/17 Fill 108.8 1 113.3 123.0 '13.6 11.0 92 5 11/10/17 RW 102.0 1 116.4 123.0 14.1 11.0 95 6 11/15/17 RW 103.0 1 117.6 123.0 14.3 11.0 96 7 11/20/17 RW 104.2 1 113.3 123.0 13.5 11.0 92 8 11/28/17 RW 105.2 1 112.9 123.0 13.3 11.0 92 9 12/1/17 RW 106.5 1 115.7 123.0 13.8 11.0 94 10 12/8/17 RW 108.4 1 116.8 123.0 14.1 11.0 95 11 12/8/17 RW 108.4 1 120.0 123.0 13.9 11.0 98 12 1/18/18 RW 109.0 1 114.5 123.0 13.2 11.0 93 13 9/18/19 RW 105.0 1 122.3 123.0 9.4 11.0 99 Tests taken by sand cone method ASTM D-1556. APPENDIX B - LABORATORY DATA PROJECT: Estrada Project No. 16-3728 549 Seaward Road Corona Del Mar, Ca A. Maximum Density -Optimum, Moisture Determination Maximum density and optimum moisture content were determined in accordance with Test Designation ASTM D 1557-07. The test results are summarized below. Sample Location Material Type Optimum Moisture Max. Dry Density % PCF As provided Brown silty sand/sandy silt 11.0 123.0 L y o o I = 8� I t; g