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Home My WebLink AboutX2017-0446 - SoilsX2017 - 0446 ' - COAST GEOTECHNICAL, INC. 601 8Gp Ave Z- 1200 West Commonwealth Avenue, Fullerton, CA 92833 Ph: 714-870-1211 Fax: 714-870-1222 e-mail:coastgeotec@sbcglobal.net July 10, 2019 Kent and Ginny Valley 1401 East Bay Avenue Newport Beach, CA 92661 References: W.O. 408810-05 Subject: Final Soils Report for New Residence at 1401 East Bay Avenue, Newport Beach, California 1. Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 408810-01, dated November 2, 2010. 2. Updated Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California by COAST GEOTECHNICAL, Inc., W.O. 408810-02, dated October 28, 2016. 3. Response to First Geotechnical Report Review of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-03, dated May 31, 2017. 4. Rough Grade Compaction Report for Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-04, dated January 5, 2018. Dear Mr. and Mrs. Valley: In accordance with your request, 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. FOUNDATION EXCAVATIONS The mat slab foundation excavations for the residence were observed on January 31, 2018. The foundation excavations were found to be acceptable at the time of our final observation. COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 2 W.O. 408810-05 Final Soils Report July10 2019 INTERIOR SLAB SUBGRADE AND TRENCH BACKFILLS The interior slab subgrade and trench backfills were observed on January 31, 2018. Garage slab subgrade was observed on February 20, 2018. Probing and testing of the interior residential slab areas indicated acceptable geotechnical conditions for support of the proposed slab. The rear patio hardscape area was observed on January 7, 2019. Probing of hardscape area subgrade indicated acceptable geotechnical conditions for support of the proposed hardscape. 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. Ming-Tarng Chen RCE 54011 No. 54011 Exp. 12/31/19 COAST GEOTECHNICAL, INC. 1200 West Commonwealth Avenue, Fullerton, CA 92833 Ph: 714-870-1211 Fax: 714-870-1222 e-mail:coastgeotec@sbcglobal.net August 7, 2019 Kent and Ginny Valley 1401 East Bay Avenue Newport Beach, CA 92661 References: W.O. 408810-06 Subject: Addendum to Final Soils Report for New Residence at 1401 East Bay Avenue, Newport Beach, California 1. Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECENICAL, Inc, W.O. 408810-01, dated November 2, 2010. 2. Updated Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California by COAST GEOTECFINICAL, Inc., W.O. 408810-02, dated October 28, 2016. 3. Response to First Geotechnical Report Review of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-03, dated May 31, 2017. 4, Rough Grade Compaction Report for Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-04, dated January 5, 2018, 5. Final Soils Report for New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-05, dated July 10, 2019. Dear Mr, and Mrs. Valley: During site construction the project contractor failed to secure geotechnical observation and testing of hardscape subgrade soils prior to concrete placement of the entire areas of hardscape planned. The City inspector has requested that the hardscape subgrade soils be assessed. OBSERVATION A hardscape area of the rear sidewalk was recently removed. Our observation of the underlying subgrade exposed indicated acceptable compaction conditions. The entry hardscape and drive approach areas of hardscape were also probed along each side and indicated relatively dense soil conditions. SUMMARY AND OPINION Based on our observations and testing, concrete thickness and reinforcement, our opinion is that the hardscape of the site is adequate for it intended use. We appreciate this opportunity to be of service to you. Respectfully submitted: COAST GEOTECHNICAL POVESS/pN R N q�F �Qk, O;CP G C 2 Min - Chen c'a No. 54011 y�Z m �` g g Daniel E. Herc RCE 54011 r Exp. 12131/19 Staff Geologist COAST GEOTECHNICAL, INC. 1200 West Commonwealth Ave.. Fullerton, CA 92833 • Ph: (714) 870-1211 • Fax: (714) 870-1222 • e -mad• coasteeotecAsbcHlobarnet January 5, 2018 Kent and Ginny Valley 1401 East Bay Avenue Newport Beach, CA 92661 References: W.O. 408810-04 Subject: Rough Grade Compaction Report for 1401 East Bay Avenue, Newport Beach, California 1. Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 408810-01, dated November 2, 2010. 2. Updated Geotechnical Engineering Investigation of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California by COAST GEOTECHNICAL, Inc., W.O. 408810-02, dated October 28, 2016. 3. Response to First Geotechnical Report Review of Proposed New Residence at 1401 East Bay Avenue, Newport Beach, California; by COAST GEOTECHNICAL, INC., W.O. 408810-03, dated May 31, 2017. Dear Mr. and Mrs. Valley: Forwarded herewith is the rough grade compaction report for the subject site. The grading operation was conducted from December 20, 2017 through January 3, 2018, using the referenced geotechnical reports as a guideline. PLACEMENT OF FILL Compacted fill material was placed on the subject site to provide adequate support for the proposed structure. Overexcavation extended down to competent existing earth material. The depth of the overexcavation was approximately three to three and a half feet below finish grade. The bottom of the excavations exposed competent native sand. The exposed surface was scarified, heavily watered, and compacted to a minimum of 90% relative compaction. Subsequent fills were moisture conditioned as needed, placed in six to eight inch loose lifts, mixed thoroughly and compacted to a minimum of 90% relative compaction by track rolling. Portland cement was mixed in the upper two feet to reduce caving for future foundation excavations. This process was followed to final grade. Import soil was needed to achieve final pad grade elevations. Limits of grading are shown on the attached Plate 1. COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 2 W.O. 408810-04 Rough Grade Compaction Report January 5, 2018 Equipment used for compacting the fill soils consisted of a Kubota SVL 90 rubber track loader and water hose. Earthwork was by Tight Quarters Inc. TESTING Maximum density optimum moisture relationship determinations were performed for each soil type encountered during grading operations. Test results were as follows: Laboratory Standard: (ASTM: D-1557) 4 -inch diameter mold; 1/30 ft3 volume; 5 layers at 25 blows per layer; 10 lb. hammer dropped 18 inches Sbli TypeSsst6€ton , OFittiunm tYdais: [e� pfo max ,DSS psity lbs leaf ", Tan Fine to Medium -Grained I 10.5 112.0 Sand Tan Fine to Coarse -Grained II 10.0 115.0 Sand with Cement Import: Gray, Silty, Fine to III 6.5 135.0 Coazse-Grained Sand Compaction tests were performed a minimum of every two feet 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- RESIDENCE The residence shall be supported by a mat foundation. The structural engineer should design the thickness and reinforcement requirements for the mat foundation for the building based on the anticipated loading conditions. The mat foundation slab should be at least twelve inches thick, with perimeter footing a minimum of 24 inches below the lowest adjacent grade. A modulus of subgrade reaction of 80 pci maybe used in the design of the mat foundation. Reinforcement shall be determined by the structural engineer. The mat foundation may utilize an allowable bearing value of 1,800 pounds per square foot. This value is for dead plus live load and may be increased by 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. All foundation bottoms shall be observed and approved by COAST GEOTECHNICAL, Inc. prior to placement of the capillary break. COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 3 W.O. 408810-04 Rough Grade Compaction Report January 5 2018 FOUNDATIONS -SECONDARY STRUCTURES Property line walls, planter walls, and other incidental foundations may utilize conventional foundation design. Continuous spread footings or isolated pads placed a minimum depth of 24 inches below lowest adjacent grade may utilize an allowable bearing value of 1,500 pounds per square foot. This value is for dead plus live load and may be increased 1/3 for total including seismic and wind loads where allowed by code. Where isolated pads are utilized, they shall be tied in two directions into adjacent foundations with grade beams. Footing excavations shall be observed by a representative of COAST GEOTECHNICAL, Inc., prior to placement of steel or concrete to verify competent soil conditions. If unacceptable soil conditions are exposed mitigation will be recommended. Foundations shall be reinforced with a minimum of four #5 bars, two top and two bottom, The structural engineer's recommendations for reinforcement shall be utilized where more severe. LATERAL DESIGN Lateral restraint at the base of footings and on slabs may be assumed to be the product of the dead load and a coefficient of friction of 0.35. Passive pressure on the face of footings may also be used to resist lateral forces. A passive pressure of zero at the surface of finished grade, increasing at the rate of 250 pounds per square foot of depth to a maximum value of 2,500 pounds per square foot, may be used for compacted fill at this site. If passive pressure and friction are combined when evaluating the lateral resistance, then the value of the passive pressure should be limited to 2/3 of the values given above. FLOOR SLABS Due to liquefaction potential at the subject site, it is recommended that a mat foundation be used for the proposed structure. The minimum thickness of the mat is twelve inches. Slab on grades shall be designed in accordance with CBC codes. Site soils are non plastic. Slab -on -grade areas shall be supported on engineered fill compacted to a minimum of 90% relative compaction and exhibiting proper moisture content. Subgrade soil should be kept moist prior to casting the slab. However, if the soils at grade become disturbed during construction, they should be brought to approximately optimum moisture content and rolled to a firm, unyielding condition prior to placing concrete. COAST GEOTECHNICAL, Inc. to verify adequacy of subgrade spoils prior to placement of vapor barrier or capillary break. COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 4 W.O. 408810-04 Rough Grade Compaction Revert January 5, 2018 Section 4.505.2.1 of the California Green Code requires the use of a capillary break between the slab subgrade and vapor barrier. The capillary break material shall comply with the requirements of the local jurisdiction and shall be a minimum of four inches in thickness. Geotechnically coarse clean sand is acceptable; however, some localities require the use of four inches of gravel (1/2 -inch or larger clean aggregate). If gravels are used, a heavy filter fabric (Mirafi 140N) shall be placed over the gravels prior to placement of the recommended vapor barrier to minimize puncturing of the vapor barrier. Additionally, a vibratory plate should be used over the gravels prior to placement of the recommended filter fabric to smooth out any sharp protuberances and consolidate the gravels. Slab areas should be underlain by a vapor retarder consisting of an engineered plastic film (as described by ASTM:E-1745). In areas where a moisture sensitive floor covering will be used and/or where moisture infiltration is not desirable, a vapor barrier with a permeance of less than O.Olperms (consistent with ACI 302.2R-06) such as 15 mil. Stego Wrap Vapor Barrier, or equivalent, should be considered, and a qualified water proofing specialist should be consulted. The vapor barrier should be underlain by the above described capillary break materials and filter cloth. The capillary break materials should be compacted to a uniform condition prior to placement of the recommended filter cloth and vapor barrier. The vapor barrier should be properly lapped and sealed. SEISMIC DESIGN Based on the CBC the following seismic design parameters are provided. These seismic design values were determined utilizing latitude 33.599498 and longitude -117.891641 and calculations from the USGS ground motion parameter calculator. A conservative site class D was assigned to site earth materials. • Site Class = D • Mapped 0.2 Second Spectral Response Acceleration, Ss = 1.737g • Mapped One Second Spectral Response Acceleration S1= 0.640g • Site Coefficient from Table 1613A.3.3(1), Fa= 1.0 • Site Coefficient from Table 1613A.3.3(2), Fv = 1.5 • Maximum Design Spectral Response Acceleration for short period, SMs = 1.737g • Maximum Design Spectral Response Acceleration for one -second period, SMI = 0.960g • 5% Design Spectral Response Acceleration for short period, SDS = 1.158g • 5% Design Spectral Response Acceleration for one -second period, Sol = 0.640g UTILITY LINE BACKFILLS All utility line backfills, both interior and exterior, shall be compacted to a minimum of 90% relative compaction and shall require testing at a maximum of two -foot vertical intervals. Utility lines shall be placed at appropriate depths. Shallow pipes can be damaged by the forces imposed by compacting backfill soils. If shallows pipes are not capable of withstanding the forces of backfill compaction, slurry backfill will be recommended. COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 5 W.O. 408810-04 Rough Grade Compaction Report January 5 2018 HARDSCAPE AND SLABS Hardscape and slab subgrade areas shall exhibit a minimum of 90% relative compaction to a depth of at least one foot. Deeper removal and recompaction may be required if unacceptable conditions are encountered. These areas require testing just prior to placing concrete. Hardscape shall be at least four inches thick and reinforced with #3 bars on 18 inch centers both ways. DRAINAGE Positive drainage should be planned for the site. Drainage should be directed away from structures via non -erodible conduits to suitable disposal areas. The structure should utilize roof gutters and down spouts tied directly to yard drainage. Pipes used for storm/site water drainage should be stout enough to withstand the force of compaction of the soils above. This force can be considerable, causing some weaker pipes to collapse. Drainage pipes shall have a smooth interior. Pipes with a corrugated interior can cause the buildup of deleterious matter, which can impede or block the flow of site waters and, as such, are not recommended. All storm/site water drainage pipes should be in conformance with the requirements of Table 1102.5 of the California Plumbing Code. Unlined flowerbeds, planters, and lawns should not be constructed against the perimeter of the structure. If such landscaping (against the perimeter of a structure) is planned, it should be properly drained and lined or provided with an underground moisture barrier. Irrigation should be kept to a minimum. Section 1804.4 of the 2016 CBC recommends five percent slope away from structures for landscape areas within ten feet of the residence. Hardscape areas shall be sloped a minimum of two percent where within ten feet of the residence unless allowed otherwise by the building official. Minimum drainage shall be one percent for hardscape areas and two percent for all other areas. We do not recommend the use of 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 within five feet of foundations. Due to the physical characteristics of the site earth materials, infiltration of waters into the subsurface earth materials has a risk of adversely affecting below grade structures, building foundations and slabs, and hardscape improvements. From a geotechnical viewpoint surface drainage should be directed to the street. The WQMP requirement shall be addressed by the Civil Engineer. POST -GRADING SERVICES During construction of the residence, it is recommended, and at rimes required by the regulatory agency, the following be observed and/or tested by the geotechnical engineer: • Foundation excavations • Slab subgrade compaction testing prior to placement of the capillary break or waste slab COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 6 W.O. 408810-04 Rough Grade Compaction Report January 5, 2018 • Slab steel placement, primary and appurtenant structures • Compaction of utility trench backfill • Hardscape subgrade compaction It is the responsibility of the developer to schedule the required observations and testing. REGULATORY COMPLIANCE I hereby certify that the subject grading was observed by a representative from this office, 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 adequate for the development. 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. Ming RCE`_ COAST GEOTECHNICAL, INC. Mr. and Mrs. Valley 7 W.O. 408810-04 Rough Grade Compaction Report January 5 2018 COMPACTION TEST RESULTS TABLE 1 ;Test = € - . �peaittxn i k I t 1 YielaW iyrgposed ti �1k� .7 Iuiax9inr Ctlrttenf 6 YY 1 ,i1mt � Weight , , (los/1 S .viz.. ,�� e _ . "a 5 Matxve C€mapac�,cixr 0 t JO .. ', Bate 1 3 1 1 Pad Area 3.03.5 15.7 101.9 I 91.0 12/20/17 2 Pad Area 3.03.5 14.5 102.1 I 91.2 12/20/17 3 Pad Area 1.52.0 10.5 104.7 lI 91.0 12/20/17 4 Pad Area 1.52.0 10.0 104.5 H 90.9 12/20/17 5 Pad Area 3.03.5 15.7 102.4 I 91.4 12/27/17 6 Pad Area 3.03.5 16.0 102.1 I 91.2 12/27/17 7 Pad Area 1.52.0 12.0 105.7 II 91.9 12/27/17 8 Pad Area 1.52.0 11.5 105.2 H 91.5 12/27/17 9 Pad Area 0.51.0 6.5 123.9 IlI 91.8 1/3/18 10 Pad Area 0.51.0 6.8 123.3 III 91.3 1/3/18 11 Pad Area F.G. 7.5 123.1 III 91.2 1/3/18 12 Pad Area F.G. 8.4 124.3 III 92.1 1/3/18 F. G.: Finish Grade COMPACTION TEST LOCATIONS Scale: r » �n — / � ! {� � 1 Approximate\!« Compaction Test Location ` - , i• _ .< >,\� ( Approximate Limits of Grading . � � ` \� b •< § \ {;VNII,\ \ - / i \ — �� . .East Bay Avenue Rough Grade Compaction Report Work Order 4ao@>R# 1401 East Bay Avenue Newport &a& California Plate No. , COAST GEOTECHNICAL, INC