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Home My WebLink AboutX2017-0189 - Soils (2)XZ0P7-0189 COAST GEOTECHNICAL, INC. 6633 93Gyadere Ter 1200 West Commonwealth, Fullerton CA 92833 • Ph(714) 870-1211 • Fax (714) 870-1222• email coastgeotecasbcelobal net May 30, 2017 Spinnaker Development, LLC Mr. Michael Close 428 32°a Street Newport Beach, CA 92663 References: W.O. 510016-04 Subject: Rough Grade Compaction Report for New Residence at 1633 Bayadere Terrace, Newport Beach, California 1. Geotechnical Engineering Investigation for Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECFINICAL, INC., W.O. 510016-01, dated July 16, 2016. 2. Revised Seismic Design Parameters, Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECFINICAL, INC., W.O. 510016-02, dated August 22, 2016. 3. First Addendum Report for Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 510016-03, dated December 16, 2016. Dear Mr. Close: Forwarded herewith is the rough grade compaction report for the subject site. Earthwork was conducted from January 25 to May 9, 2017. COAST GEOTECHNICAL, INC. provided observation and testing of the grading. POOL ABANDONMENT A swimming pool was previously abandoned on the property; however, the pool shell was left in place. Per recommendations of our Reference 1, the previous pool backfill and pool shell were removed under observation of Coast Geotechnical. The pool shell was removed exposing competent bedock. The exposed excavation bottom was scarified, moisture conditioned as needed, and track rolled to a firm compact conditon. Subsequent soil backfill was placed in six to eight inch loose lifts, moisture conditioned with a water hose as needed, and compacted to a minimum of 90% relative compaction by rolling with a CAT 953 track loader. Earthwork was by Tight Quarters, Inc. The approximate pool backfill area and compaction test locations are shown on the Compaction Test Location Plan, Plate 1. COAST GEOTECHNICAL, INC. Mr. Michael Close 2 W.O. 510016-04 Rough Grade Compaction Report May 30. 2017 GRADING FOR MAIN HOUSE LEVEL The grading operation for the main residence level was conducted on March 6 and March 7, 2017, utilizing the referenced geotechnical reports as a guideline. Compacted fill material was placed on the subject site to provide uniform support for the proposed residence. Overexcavation extended into bedrock, at a depth of about three feet below final grade. The exposed excavation bottom was scarified, moisture conditioned as needed, mechanically compacted. Fills were placed in six to eight inch loose, moisture conditioned lifts, and compacted to a minimum of 90% relative compaction by rolling with a CAT 953 track loader. Earthwork was by Tight Quarters, Ino. Mosture control was with a water hose SHORING Shoring along the north and south property lines of the basement level area was installed between February 13, 2017 and March 27, 2017. Shoring consisted of thirty-two piles extending 15%z to 38 feet below grade. The piles were embedded below the depth of the basement/lower level in accordance with approved plans. Wood lagging was placed between piles to support the adjacent properties in accordance with approved plans. Backfill of the "H" beam and boring annulus consisted of cement slurry. Backfill of the void between the back of lagging and required construction cut was with cement slurry. Shoring was installed by Drillco. OBSERVATION OF BASEMENT GRADING Upon completion of the shoring and lagging, the excavation of the basement area proceeded. The basement excavation encountered competent bedrock. Temporary verticals were limited to four feet or less with 1:1 (H:V) laybacks above. Due to seepage waters, a temporary sump pit and drainage trench was installed along the backcut to control the nuisance water during excavation and construction. The bottom of the basement excavation was over -excavated about one foot below subgrade. The exposed surface was scarified, moisture conditioned as needed, and compacted mechanically. Subsequent fills were placed in six to eight inch loose, moisture conditioned lifts, and compacted to a minimum of 90% relative compaction Limits of grading are shown on the attached Plate 1. Earthwork was by Tight Quarters, Inc.. Equipments utilized consisted of a CAT 963 -track loader and a CAT 953 track loader. Moisture control was by a water hose as needed. COAST GEOTECHNICAL, INC. Mr. Michael Close 3 W.O. 510016-04 Rough Grade Compaction Report May 30, 2017 TESTING Maximum density optimum moisture relationship determinations were performed for each soil type encountered during grading operations. Test results are as follows: Laboratory Standard: (ASTM:D-1557) 4 inch dia. mold; 1/30 cu.ft.vol.; 5 layers -25 blows per layer; 10 IN hammer dropped 18 inches Compaction tests were performed as fill placement progressed at approximate two to three foot intervals and/or 500 cubic yards of compacted fill soils placed. These tests were performed in accordance with ASTM test methods. The test results are summarized in Table 1. The approximate test locations are shown on Plate 1. FOUNDATIONS The proposed structures shall be supported by a mat foundation or a conventional foundation system. A conventional foundation system shall consist of spread footings and/or isolated pad footings, bearing into compacted fill, placed a minimum depth of 24 inches below lowest adjacent grade utilizing an allowable bearing value of 2,000 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. The structural engineer's reinforcing requirements should be followed if more stringent. C Where isolated pads are utilized, they shall be tied in two directions into adjacent foundations with grade beams. If a mat slab design is utilized, the structural engineer should design the thickness and reinforcement requirements for the mat foundation for the building based on the anticipated loading conditions. The mat foundation slab should be at least twelve inches thick, with Yellow Brown Diatomaceous Silt I with Bedrock Fragments 20.0 100.0 Brown Sandy Silt with Bedrock II 17.0 110.0 Fragments III Dark Brown Clayey Sand 12.0 115.0 Light Gray to Tan Gray IV Diatomaceous Silt with Bedrock 21.5 95.0 Compaction tests were performed as fill placement progressed at approximate two to three foot intervals and/or 500 cubic yards of compacted fill soils placed. These tests were performed in accordance with ASTM test methods. The test results are summarized in Table 1. The approximate test locations are shown on Plate 1. FOUNDATIONS The proposed structures shall be supported by a mat foundation or a conventional foundation system. A conventional foundation system shall consist of spread footings and/or isolated pad footings, bearing into compacted fill, placed a minimum depth of 24 inches below lowest adjacent grade utilizing an allowable bearing value of 2,000 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. The structural engineer's reinforcing requirements should be followed if more stringent. C Where isolated pads are utilized, they shall be tied in two directions into adjacent foundations with grade beams. If a mat slab design is utilized, the structural engineer should design the thickness and reinforcement requirements for the mat foundation for the building based on the anticipated loading conditions. The mat foundation slab should be at least twelve inches thick, with COAST GEOTECHNICAL, INC. Mr. Michael Close 4 W.O. 510016-04 Rough Grade Compaction Report May 30.2017 perimeter footings ( at -grade level only) a minimum of 24 inches below the lowest adjacent grade. A modulus of subgrade reaction of 80 pci may be used in the design of the mat foundation. Reinforcement shall be determined by the structural engineer. Alternate foundations and/or additional ground modification techniques, for support of the structure, can be addressed upon request of the project manager. All foundation plans are subject to review and approval of the soils engineer. Foundations for site walls and retaining walls structurally separated from the residence may derive support from bedrock. Foundations into bedrock may utilize a bearing value of 2000 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. The structural engineer's reinforcing requirements should be followed if more stringent. Footing excavations shall be observed by a representative of COAST GEOTECHNICAL, INC., prior to placement of steel or concrete to verify competent soil conditions. If unacceptable soil conditions are exposed mitigation will be recommended. LATERAL DESIGN Lateral restraint at the base of footings and on slabs may be assumed to be the product of the dead load and a coefficient of friction of .35. Passive pressure on the face of footings may also be used to resist lateral forces. A passive pressure of zero (0) at the surface of finished grade, increasing at the rate of 350 pounds per square foot of depth to a maximum value of 3,500 pounds per square foot, may be used for compacted fill at this site and 450 pounds per square foot of depth to a maximum value of 6,750 pounds per square foot may be used for piles into bedrock. Where passive pressure and friction are combined when evaluating the lateral resistance, the value of the passive pressure should be limited to 2/3 of the values given above. WATERPROOFING There is an inherent risk with moisture problems when constructing below grade rooms. The geotechnical consultant is only responsible for identification of adverse moisture conditions, which will impact below grade rooms at this site. Seepage waters were encounteerd at the base of site excavations in one area of the basemnet area. The waterproofing for the basement floor and walls should be designed accordingly by a qualified person. Basement floors and walls should be designed watertight. SUBDRAINS Subdrain systems shall be installed behind retaining walls and at a minimum they shall consist of four -inch diameter SCH 40 or SDR 35 perforated pipe surrounded with one cubic foot, per lineal pipe foot, of 3/4 -inch gravel. The gravel shall be wrapped in filter fabric. Outlet pipes shall be solid pipe of similar material. COAST GEOTECHNICAL, INC. Mr. Michael Close 5 W.O. 510016-04 Rough Grade Compaction Report Mav 30, 2017 Subdrains for basement walls shall be placed below the elevation of the basement floor. Subdrain systems shall be independent of area surface drains and roof drains. Subdrain placement requires observation and approval by COAST GEOTECHNICAL, Inc. EXPANSIVE SOILS Results of expansion tests indicate that the near surface soils have a high expansion potential. Current practice in Southern California dictates substantial reinforcement, slab thickening, moisture barriers, and pre -saturation of subgrade soils as a method of minimizing the effects of expansive soil, not eliminating them. The design guidelines presented in reference 1 are minimum geotechnical guidelines considered appropriate for the site and are not intended to supersede the structural engineer's design criteria or those required by code. FLOOR SLABS An engineered fill mat compacted to a minimum of 90% relative compaction with a 2-3% over optimum moisture content shall support all proposed slabs. Slab on grades shall be designed in accordance with CBC codes. Concrete slabs supported by engineered fill soil may be designed utilizing values of 1.0 for Co and 1.0 for Cs with an effective plasticity index of 20, and in accordance with publications or methods stated in the appropriate section of the building code. Minimum geotechnical recommendations for slab on grade design are five inch actual thickness with #4 bars at twelve inches on center each way. Structural design may require additional reinforcement and slab thickness or use of alternate foundation and slab systems. If the soils at grade become disturbed during construction, they should be brought to 34% over optimum moisture content and rolled to a firm, unyielding condition prior to placing concrete. COAST GEOTECHNICAL, Inc. will need to verify adequate mitigation. Prior to placement of sand or visqueen COAST GEOTECHNICAL, Inc., shall test the slab subgrade soils for moisture content. If the subgrade soils do not exhibit the recommendations in reference 1, they shall be moisture conditioned to the required depth and content. The capillary break material shall comply with the requirements of the local jurisdiction and shall be a minimum of four inches in thickness. The City of Newport Beach requires the use of four inches of gravel (1/2 -inch or larger clean aggregate). A heavy filter fabric (Mirafi 140N) must be placed over the gravels prior to placement of the recommended vapor barrier to minimize puncturing of the vapor barrier. Additionally, a vibratory plate should be used over the gravels COAST GEOTECHNICAL, INC. Mr. Michael Close 6 W.0, 510016-04 Rough Grade Compaction Report Mav 30. 2017 prior to placement of the recommended filter fabric to smooth out any sharp protuberances and consolidate the gravels. Slab areas should be underlain by a vapor retarder consisting of an engineered plastic film (as described by ASTM:E-1745). In areas where a moisture sensitive floor covering will be used and/or where moisture infiltration is not desirable, a vapor barrier with a permeance of less than 0.01perms (consistent with ACI 302.2R-06) such as 15 mil. Stego Wrap Vapor Barrier, or equivalent should be considered, and a qualified water proofing specialist should be consulted. The vapor barrier should be underlain by the above described capillary break materials and filter cloth. The capillary break materials should be compacted to a uniform condition prior to placement of the recommended filter cloth and vapor barrier. The vapor barrier should be properly lapped and sealed. Positive drainage should be planned for the site. Drainage should be directed away from structures via non -erodible conduits to suitable disposal areas. The structure should utilize roof gutters and down spouts tied directly to yard drainage. Unlined flowerbeds, planters, and lawns should not be constructed against the perimeter of the structure. If such landscaping (against the perimeter of a structure) is planned, it should be properly drained and lined or provided with an underground moisture barrier. Irrigation should be kept to a minimum. The current CBC recommends 5% slope away from structures for landscape areas within ten feet of the residence, with 2% slope allowable where justified. Our justification is the use roof drains tied into area drains, the use of area drains, and site grading which will mitigate the potential for moisture problems beneath a slab on grade. Hardscape areas shall be sloped a minimum of 2% where within ten feet of the residence unless allowed otherwise by the building official. Minimum drainage shall be one percent for hardscape areas and two percent for landscape areas for all other areas. We do not recommend the use of bottomless trench drains to conform with infiltration best management practice (BMP) such as infiltration trenches, infiltration basins, dry wells, permeable pavements or similar systems designed primarily to percolate water into the subsurface soils. Due to the physical characteristics of the site earth materials, infiltration of waters into the subsurface earth materials has a risk of adversely affecting below grade structures, building foundations and slabs, and hardscape improvements. From a geotechnical viewpoint surface drainage should be directed to the street. The WQMP requirement shall be addressed by the Civil Engineer. COAST GEOTECHNICAL, INC. Mr. Michael Close 7 W.O. 510016-04 Roueh Grade Compaction Report May 30 2017 SLOPE MAINTENANCE 1. Slopes should be planted with appropriate drought -resistant vegetation. 2. The face of slope should be planted as soon as possible. Hydro -seeding or jute netting may be used to reduce erosion prior to the establishment of vegetation. Slopes should not be over -irrigated. Heavy ground cover combined with over -watering is a primary source of surficial slope failures. 4. Animal burrows can serve to collect normal sheet flow on slopes and cause rapid and destructive erosion and should be controlled or eliminated. 5. In no instance should roof drainage, yard drainage, or water from swimming pools or other sources be diverted to flow onto graded or natural slopes. 6. Modification to slopes, including all placement of fill materials or excavations that steepen or otherwise modify the designed or natural slope angle, should not be attempted. All modifications to slopes should be made only after evaluation and approval of the soils engineer/geologist. POST -GRADING SERVICES During construction of the residence, it is recommended, and at times required by the regulatory agency, the following be observed and/or tested by the geotechnical engineer: • Excavation of footings • Backfill of interior trenches • Testing of interior slab areas • Backfill of exterior utility trenches • Hardscape subgrade • Backfill of retaining/basemnet walls • Pool excavation • Subdrain placement It is the responsibility of the developer to schedule the required observations and testing listed or not. REGULATORY COMPLIANCE I hereby certify that the subject grading was observed by me, and the work was done in full compliance with the Grading Ordinance of the City of Newport Beach, and in accordance with the best accepted practices of the applicable chapter of the California Building Code. All cuts, fills or processing of original ground under the purview of this report have been completed under the observation of and with selective testing by COAST GEOTECHNICAL, INC., and found to be in compliance with the Grading Code of the City of Newport Beach. The completed work has been observed by COAST GEOTECHNICAL, INC., and is considered COAST GEOTECHNICAL, INC. Mr. Michael Close 8 W.O. 510016-04 Rough Grade Compaction Report May 30, 2017 adequate for it intended use. Our findings were made and recommendations prepared in accordance with generally accepted professional engineering practices, and no further warranty is implied nor made. This report is subject to review by the controlling authorities for this project. We appreciate this opportunity to be of service to you. Respectfully submitted: COAST GEOTECHNICAL, INC. C 4� Ming-Tarng Chen RCE 54011 No.54011 z ' rExp 12-31-17 k COAST GEOTECHNICAL, INC. MT. Michael Close 9 W.O. 510016-04 Rough Grade Compaction Report May 30,2017 COMPACTION TEST RESULTS TABLE 1 r�es t �16eatoi B I.Relative Below Tr6pose&ontent Moisture Dry,unit :1�� weigh S 3 ob 4ft )Te - ". Compaction": detion� :- 11 Datelk x -A I Pool Backfill 6.06.5 19.1 92.0 1 92.0 1/25/17 2 Pool Backfill 4.55.0 19.0 100.0 11 90.9 1/25/17 3 Pool Backfill 3.03.5 18.2 100.1 11 91.0 1/25/17 4 Pool Backfill 1.52.0 17.1 100.0 11 90.9 1/25/17 5 Upper Pad 2.53.0 22.0 92.1 1 92.1 3/6/17 6 Upper Pad 2.03.0 21.0 92.5 1 92.5 3/6/17 7 Upper Pad 1.01.5 19.5 102.7 11 93.4 3/6/17 8 Upper Padl 2.02.5 21.2 101.4 11 92.2 3/6/17 9 Upper Pad 1.01.5 16.5 107.1 111 93.1 3/7/17 10 Upper Pad F.G 14.2 106.5 ill 92.6 3/7/17 11 Upper Pad F.G. 15.5 105.2 111 91.5 3/7/17 12 Basement Pad 1.01.5 24.0 87.0 IV 91.6 5/2/17 13 Basement Pad 1.01.5 21.9 88.0 IV 92.6 5/2/17 14 Basement Pad 1.01.5 24.5 86.5 IV 91.0 5/8/17 15 Basement Pad F.G. 23.8 87.1 IV 91.7 5/8/17 16 Basement Pad F.G. 25,0 87.1 IV 91.7 5/9/17 17 Basement Pad F.G. 23.7 86.8 TV 91.4 5/9/17 18 Basement Pad F.G. 24.2 87.2 IV 91.8 5/9/17 19 Basement Pad F.G. 23.9 87.3 ry 91.9 5/9/17 F.G. --- Finish Grade PREPARED BY: N FORKERT ENGINEERING & SURVEYING. INC. 22511 BROOKHURST ST. STE 203 HUNTINGTON BEACH, CA 92646 (/14)963-5793 JN 9114 ,I I1 1 1 1j I I I' .. 1 em ama w MRS is 11 ii114 i EDI Iri i -1II! I R' AL FTVEMEN � 111 I 11 1 II II 11�Ts"�' I I�� I u : It Scale: 1'1= 201 Work Order 510016-04 Plate 1 COAST GEOTECHNICAL, INC. 1200 West Commonwealth Avenue, Fullerton, CA 92833 Ph:714-870-1211 Fax:714-870-1222 e-mail:coastgeotecCsbcglobal.net September 17, 2019 Mr. Michael Close Spinnaker Development, LLC 428 32nd Street Newport Beach, CA 92663 References: W.O. 510016-07 Subject: Final Soils Report for 633 Bayadere Terrace, Newport Beach, California 1. Geotechnical Engineering Investigation for Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 510016-01, dated July 16, 2016. 2. Revised Seismic Design Parameters, Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 510016-02, dated August 22, 2016. 3. First Addendum Report for Proposed New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 510016-03, dated December 16, 2016. 4. Rough Grade Compaction Report for New Residence at 1633 Bayadere Terrace, Newport Beach, California; by COAST GEOTECI-DUCAL, INC., W.O. 510016-04, dated May 30, 2017. 5. Addendum to Geotechnical Recommendations for 1633 Bayadere Terrace, Newport Beach, California by COAST GEOTECHNICAL, INC., W.O. 510016-05, dated June 20, 2017. 6. Revised Addendum to Geotechnical Recommendations for 1633 Bayadere Terrace, Newport Beach, California by COAST GEOTECHNICAL, INC., W.O. 510016-06, dated June 21, 2017. Dear Mr. Close: In accordance with the request of your contractor, this final soils report has been prepared to address geotechnical observations and testing performed since completion of rough grading. This report addresses requested observations and testing. Copies of our daily reports are maintained in our files. IWAIJ10I1/11►C1JZ1717EYiI1111!C171T/ D►lel\�/YY[I)►1 The pool excavation was observed on May 18 and May 23, 2017. Probing and testing of the pool excavation indicated acceptable geotechnical conditions for support of the proposed pool. FOUNDATION EXCAVATIONS Foundation excavations for the lower and upper portions of the residence were observed on June 22, 2017, July 6, 2017, and December 5, 2017. The foundation excavations were found to be acceptable at the time of our final observations. COAST GEOTECHNICAL, INC. 1&. Close 2 W.O. 510016-07 Final Soils Report September 17, 2019 SLAB SUBGRADE AND TRENCH BACKFILL The residence and garage slab subgrades, and interior trench backfill were observed on June 30, 2017 and January 23, 2018. Probing and testing of the interior residential and garage slab and trench backfill areas indicated acceptable geotechnical conditions for support of the proposed slabs. BASEMENT SUBDRAIN & BACKFILL The subdrain for the basement was observed on October 26, 2017 and consisted of four inch diameter SDR 35 perforated drain pipe (holes down), surrounded by one cubic foot per lineal foot of 3/4 -inch rock wrapped in filter cloth. The subdrain was placed in accordance with plans and geotechnical recommendations. Proper outlets of the subdrain system are the responsibility of the contractor. Backfill of the basement walls was observed from October 27, 2017 through November 1, 2017. Basement wall backfills consisted of the gravel to within four feet of finish grade. The gravel was compacted as it was placed with hand wackers then covered with filter cloth prior to placement of the soil cap. The soil cap consisting of onsite earth materials was compacted to a minimum of 90% relative compaction. Backfill soils were placed in thin; moisture conditioned lifts, compacted, and demonstrated a minimum of 90% relative compaction up to finish pad grade elevations. V. M:4DWSY\Wy A majority of the hardscape encompassing the residence was placed without geotechnical approval prior to the concrete placement. Our observations of September 16, 2019 discovered that the hardscape was constructed with a series of mow strips and planters adjacent to the hardscape. Probing within the exposed subgrade areas adjacent to the hardscape indicated competent compacted conditions. The slab subgrade areas are judged to be sufficiently compacted and are adequate for their intended use. OPINION It is opinion of COAST GEOTECHNICAL, INC. that the summarized geotechnical conditions approved by this office are in compliance with approved geotechnical reports and Newport Beach building codes. The final grades appear to conform to approved plans. We appreciate this opportunity to be of service to you. Respectfully Submitted: COAST GEOTECHNICAL, INC QPpFESS/pN CPRNc �, �F �� No. 5101 i m Daniel E. Her Ming-TarngChen Exp. 12/31 /19 a RCE 54011 Staff Geologist