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Home My WebLink AboutX2018-0902 - Soils (2)COAST GEOTECHNICAL, INC. 1200 West Commonwealth Avenue, Fullerton, CA 92833 Ph:714-870-1211 Fax:714-870-1222 e-mail:coastgeotec�yn sbcglobal.net September 19, 2019 Mayo Family Trust C/o Jeremy Grissinger 1863 Port Renwick Place Newport Beach, CA 92660 References: W.O. 541717-06 o Yy2�-0as-0a0z 183 Port STerhi,5 �0 Subject: Final Soils Report for 1837 Port Sterling Place, Newport Beach, California 1. Geotechnical Engineering Investigation of Proposed New Residence at 1837 Port Stirling Place, Newport Beach, California, by COAST GEOTECHNICAL, INC., W.O. 541717-01, dated December 22, 2017. 2. Response to Water Quality Management Plan Review Comment, Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-02, dated May 22, 2018. 3. Addendum Report, Percolation Test Results, Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-03, dated July 11, 2018 4. Response to First Geotechnical Report Review Checklist for Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-04, dated July 23, 2018. 5. Rough Grade Compaction Report Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-05, dated August 7, 2018 Dear Mr. Grissinger: 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 Foundation excavations for the property -line wall were observed on September 7, 2018. Foundation excavations for the residence were observed on September 25, 2018. The footings excavations were found to be acceptable at the time of our observations. COAST GEOTECHNICAL, INC. Mayo Family Trust 2 W. O. 541717-06 Final Soils Report September 19, 2019 INTERIOR SLAB SUBGRADE AND TRENCH BACKFILLS The interior slab subgrade and trench backfills were observed on October 5 & 8, 2018. Probing and testing of the interior residential slab area indicated acceptable geotechnical conditions for support of the proposed slab at the time of our final observation. HARDSCAPE Hardscape subgrades of the driveway, rear patio and walkway areas were observed on September 16 & 18, 2019. Probing and testing of hardscape area subgrades 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. l\---t�- Ming-Tarng Chen /�Q� R RCE 54011 x"O,c� �P No. 54011 Exp. 12/31/19 amel E. Her Staff Geologist COAST GEOTECHNICAL, INC. 1200 W. Commonwealth Avenue, Fullerton, CA 92833 Ph: (714) 870-1211 Fax: (714) 870-1222 E-mail: coastgeotec@sbcglobal.net August 7, 2018 W.O. 541717-05 Mayo Family Trust C/o Mr. Jeremy Gissinger 1863 Port Renwick Place Newport Beach, CA 92660 Subject: Rough Grade Compaction Report, Proposed New Residence at 1837 Port Stirling Place, Newport Beach, California References: 1. Geotechnical Engineering Investigation of Proposed New Residence at 1837 Port Stirling Place, Newport Beach, California, by COAST GEOTECHNICAL, INC., W.O. 541717-01, dated December 22, 2017. 2. Response to Water Quality Management Plan Review Comment, Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-02, dated May 22, 2018. 3. Addendum Report, Percolation Test Results, Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-03, dated July 11, 2018 4. Response to First Geotechnical Report Review Checklist for Proposed New Residence at 1837 Port Stirling, Newport Beach, California; by COAST GEOTECHNICAL, Inc., W.O. 541717-04, dated July 23, 2018. Dear Mr. Gissinger: Forwarded herewith is the rough grade compaction report for the subject site. Our observations and testing were performed periodically, as requested. The grading operation for the residential development consisted of grading the residential pad area to provide uniformly compacted fill soils for support of the residence. The grading operation was conducted from July 27, 2018 through August 2, 2018. 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 over - excavation was about 3.0 to 3.5 feet below proposed finish grade. The exposed surface was scarified; moisture conditioned, and compacted to a minimum of 90% relative compaction. Subsequent fills were placed in six to eight inch loose lifts, moisture conditioned as needed, and compacted to a minimum of 90% relative compaction by track rolling. This process was followed to final grade. Limits of grading are shown on the attached Plate 1. COAST GEOTECHNICAL, INC. Mr. Jeremy Gissinger 2 W.O. 541717-05 Rough Grade Compaction Report August 7 2018 Equipment used for the compaction of fill soils consisted of a CAT 953 track loader. Soils were moisture conditioned by a water hose where needed. 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 W volume.; 5 layers at 25 blows per layer; 10 lb. hammer dropped 18 inches Soil -Type . Classification ° Optimum Moisture /o Max Ary Densrty, lbs/ft3 I Brown Silty Sandy Clay 10.5 125.0 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. FOUNDATION ON COMPACTED FILL- RESIDENCE Conventional foundations may consist of spread footings or isolated pads placed a minimum depth of 24 inches below lowest adjacent grade utilizing an allowable bearing value of 1,800 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 footing width shall be at least 15 inches for the proposed two-story residence. Isolated pad footings shall be tied by grade beams to adjacent footings. It is recommended that all footings be reinforced with a minimum of four #5 bars (two top and two bottom). 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. 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 0.30. 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 300 pounds per square foot of depth to a maximum value of 3,000 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, the value of the passive pressure should be limited to 2/3 of the values given above. COAST GEOTECHNICAL, INC. Mr. Jeremy Gissinger 3 W.O. 541717-05 Roueh Grade Compaction Report August 7, 2018 SEISMIC DESIGN Based on the 2016 CBC the following seismic design parameters are provided. These seismic design values were determined utilizing latitude 33.621770 and longitude -117.857098 and calculations from the USGS Seismic Tool Application. A conservative site class D was assigned to site earth materials. Site Class = D • Mapped 0.2 Second Spectral Response Acceleration, Ss = 1.632g • Mapped One Second Spectral Response Acceleration Sl = 0.594g • Site Coefficient from Table 1613A5.3(1), Fa =1.0 Site Coefficient from Table 1613A5.3(2), Fv = 1.5 • Maximum Design Spectral Response Acceleration for short period, SMs = 1.632g • Maximum Design Spectral Response Acceleration for one -second period, Sm, = 0.891 g • 5% Design Spectral Response Acceleration for short period, SDs = 1.088g • 5% Design Spectral Response Acceleration for one -second period, SD1= 0.594g SETTLEMENT The maximum total post -construction settlement is anticipated to be on the order of one-half inch. Differential settlements are expected to be less than 1/2 inch, measured between adjacent structural elements over a distance of forty feet. EXPANSIVE SOILS Results of expansion tests indicate that the near surface soils have a medium expansion potential. The medium recommendations on the accompanying Expansive Soil Recommendations Chart, Plate A, Reference 1, shall be utilized in design. FLOOR SLABS Where conventional foundation and slab on grade is utilized, the slab shall be supported on engineered fill compacted to a minimum of 90% relative compaction. For design of slab on grade a computed effective plasticity index of 25 may be utilized. Minimum geotechnical recommendations for on grade slab design are five inches actual thickness, with #4 bars at twelve inches on center each way. If the soils at grade become disturbed during construction, they shall be brought to 2-3% over optimum moisture content and compacted to a minimum of 90% relative compaction prior to placing concrete. COAST GEOTECHNICAL, Inc. will need to verify adequate mitigation. The 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. Mr. Jeremy Gissinger q W.O. 541717-05 Rough Grade Compaction Report August 7, 2018 The capillary break material shall comply with the requirements of the local jurisdiction and shall be a minimum of four inches in thickness and consist of gravel (1/2 -inch or larger clean aggregate). A heavy filter fabric should be placed over the gravels prior to placement of the recommended vapor retarder to minimize puncturing of the vapor retarder. Slab areas should be underlain by a vapor retarder consisting of an engineered plastic film (as described by ASTM:E-1745). A vapor barrier with a permeance of less than 0.01perms (consistent with ACI 302.211-06) such as 15 mil. Stego Wrap Vapor Barrier, or equivalent should be considered. The vapor barrier should be underlain by the above described capillary break material 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 and in contact with the slab bottom. SOLUBLE SULFATES Typical on-site soils showed a soluble sulfate content of 100 ppm. Based on the Table 4.3.1 of ACI 318-05, concrete with Type II cement and a minimum compressive strength of 2,500 psi may be utilized. The structural engineers design criteria may be more stringent. Concrete shall be placed in accordance with appropriate codes. 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. COAST GEOTECHNICAL, INC. shall be present during backfill placement and compaction to verify compliance. POOL DESIGN Any conventional future pool/spa shall be designed as free standing and supported by competent native earth material. Pool walls shall be designed to support the water, having a density of 62.4 pounds per cubic foot without bearing from adjacent soil. The walls should be able to support the adjacent soil when the pool is empty. The earth pressure may be calculated as an equivalent fluid pressure of 100 pounds per cubic foot for level backfill, plus the lateral pressure due to any superimposed surcharge when the pool is empty. Expansion joints shall be placed between the pool and deck. All pool utility lines shall be backfilled with soils compacted to a minimum of 90% relative compaction. Where pool lines are sensitive to the use of compaction equipment the trenches shall be backfilled with two sack slurry. COAST GEOTECHNICAL, Inc. shall verify the backfill of all trenches. Pool decking shall be cast free of the swimming pool structure and access openings. The free space shall be filled with flexible water stop materials. The client is advised that due to the expansive nature of site soils that some horizontal and vertical movement between the pool and pool decking will occur over time. COAST GEOTECHNICAL, INC. Mr. Jeremy Gissinger 5 W.O. 541717-05 Rough Grade Compaction Report August 7, 2018 The pool foundation excavation shall be observed and approved by COAST GEOTECHNICAL, Inc. prior to the placement of reinforcement. These recommendations are subject to change based on the review of pool plans. HARDSCAPE AND SLABS Hardscape and slab subgrade areas shall exhibit a minimum of 90% relative compaction to a depth of two feet. Deeper removal and recompaction may be required if unacceptable conditions are encountered. Concrete slabs shall be a minimum of four inches actual thickness with #4 bars on 12 inch centers each way. Exterior hardscape slabs will be subject to volume changes in subgrade soils, which may lead to cracking. Movement of slabs adjacent to structures can be mitigated by doweling slabs to perimeter footings. Doweling should consist of No. 4 bars bent around exterior slabs. Doweling should be spaced no farther than 36 inches on centers. As an option to doweling, an architectural separation could be provided between the main structure and abutting appurtenance improvements. Presaturation of exterior slab areas is also desirable. At exterior edges of patios and other flatwork, a thickened edge containing reinforcement is highly recommended. If no significant load is associated with the edge of the slab, the depth and width of the thickened edge may be limited to eight inches. Reinforcement adopted for the main structure may be applied to the appurtenances. As an alternative to rigid hardscape or brickwork, flexible pavers may be utilized. 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. 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 2016 CBC recommends 5% slope away from structures for landscape areas and 2% slope away for hardscape areas, within ten feet of a residence. 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 within ten 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. COAST GEOTECHNICAL, INC. Mr. Jeremy Gissinger ( W.O. 541717-05 Rough Grade Compaction Report August 7 2018 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 residential footings • Backfill of interior slab areas • Backfill of interior trenches • Backfill of exterior utility trenches • Pool excavation • Hardscape subgrade 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. C Ming-Tarng Chen RCE 54011 COAST GEOTECHNICAL, INC. Mr. Jeremy Gissinger 7 W.O. 541717-05 Rough Grade Compaction Report August 7, 2018 COMPACTION TEST RESULTS TABLE 1 Test ,No S ocation Below Proposed :.Grade-(lbsf£t)YPe Motsture Content- DryUmt Vyeight Soil ILelahve „' Compachan o �o 1�afe 1 Pad Area 3.03.5 12.5 116.6 I 93.3 7/27/18 2 Pad Area 3.03.5 12.2 116.9 I 93.5 7/27/18 3 Pad Area 2.02.5 13.4 113.8 I 91.0 7/30/18 4 Pad Area 2.02.5 12.0 114.9 I 91.9 7/30/18 5 Pad Area 1.52.0 13.1 114.3 I 91.4 7/30/18 6 Pad Area 1.01.5 12.3 115.5 I 92.4 7/30/18 7 Pad Area 3.03.5 12.2 117.2 I 93.7 7/31/18 8 Pad Area 3.03.5 11.9 116.6 I 93.3 7/31/18 9 Pad Area 2.02.5 12.1 114.8 I 91.8 7/31/18 10 Pad Area 1.52.0 13.4 114.4 I 91.5 7/31/18 11 Pad Area 0.51.0 13.3 116.0 I 92.8 8/1/18 12 Pad Area 1.0-1.5 14.1 117.1 I 93.7 8/1/18 13 Pad Area F.G. 11.0 116.2 I 93.0 8/2/18 14 Pad Area F.G. 11.9 115.6 1 92.5 8/2/18 F.G.: Finish Grade COMPACTION TEST LOCATION PLAN I PORT STIRLING PLACE — Q 7TT J . �� d 4i § Scale: P= 20' a i � 3 J J •1 Approximate , 11 1 Compaction a Test Location y I "r •9 flSv � ems Approximate Limits of �e Grading ¢, A .5 •3 8 _ �7 s •. 6 / t ' L y ❑ P �.� �� I tlil 1 � I� I „Ila: llt t ❑ t � lel tlt 1�t ICR Rill tH--+a +.T—.� 'S 1l IIII llll 1 111 Ill 1 1 111 tl 1 �1 , U t 11 t Rt ID!4 1 It Ill 11 Il1 t llt I ll 11 -1. Ill � 1 1 II 1l 1 - 1 1 8 . V t 1 1 1' 0 llN1 1 „t 1! t R I I yy�I REIT 11 l IltlRgU yUl IFI i R 11 11 n! �y I t 1 Rill I R1 � h ,I llRill 11�: !� 11 ,l O�tPt II llt 11 RI Il(a II 11� O 1 .' �C� � 11(111 � 1 qt❑ 1 n Il �I Rlll --'*' 1 �: PRFPMm af. �— Il.l :.. >%�:... Ij XNf11NGiONBFMAtG9g16 '�_�,. Rough Grading Compaction Report Work Order 541717-05 1837 Port Stirling Place Newport Beach, California Plate No. 1 COAST GEOTECHNICAL, INC,