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HomeMy WebLinkAbout4-18-2019_submittal_Soils Rpt MIN. DESIGN ITEM RECOMMENDATIONS 1Q P.C. 02-06-2019 engineering tolerable amounts. The above specifications eliminate the use of piles and Mat foundations: z eotecbnical associated construction vibrations and groundwater displacement induced b allowable bearing Q2 P.C. 02-20-2019 g 9 P Y g pressure: 2,250 psf applications caisson drilling or pile-driving. If the above specifications are incorporated, the passive lateral resistence: 250 psf per foot consultants November 30, 2018 proposed structure shall be stable and adequate for the intended uses and the mat slab thickness: min. 12 inches with thickened edges (+ 6 inches) Project No. BS157.1 proposed construction will not adversely impact the subject or adjacent steel reinforcement: no. 5 bars @ 12" o.c. each way, top and bottom Site: Proposed Beach . California properties.Story SFR: 18 Balboa Coves coefficient of friction: 0.30 Newport Beies. Modulus of Subgrade Reaction: ks = 90 Ibs/in' Executive Summary Other Geologic Hazards Cement Type for Concrete in Contact with On-Site Earth Materials gER gRcy�� Based on our geotechnical study of the site, our review of available reports and literature and our Other geologic hazards such as landsliding, or expansive soils, do not appear to Concrete mix design should be based on sulfate testing with Section 1904.2 of experience, it is our opinion that the proposed residential development is feasible from a geotechnical be evident at the subject site. v Smi> =t the 2016 CBC. Preliminary laboratory testing indicates the site soils possess I * m$.nd C 14146 negligible sulfate exposure. standpoint. ere appear to be no significant geotechnical constraints on-site that cannot be mitigated by v'� o 1 1-30-19 2� proper planning, design, and utilization of sound construction practices. The engineering properties of the soil and native materials, and surfaceCONCLUSIONS ace drainage offer favorable conditions for site re-development. 9T ACI 318-14 BUILDING CODE (Table 19.3.1.1) FOF CA��FO The following key elements are conclusions confirmed from this investigation: Based on our geotechnical study Of the site, our review of available reports and REQUIREMENTS FOR CONCRETE EXPOSED TO SULFATE-CONTAINING SOLUTIONS literature and our experience, it is our opinion that the proposed improvements at the Sulfate Water soluble Sulfate So A review of available geologic records indicates that no active faults cross the subject property. site are feasible from a geotechnical standpoint. There appear to be no significant Exposure sulfate so ( <)in Cement Type Maximum water- Minimum fc', The site is located in the seismically active Southern California area, and within 2 kilometers of the 9 p PP g ( ,>in soil water,ppm cementitious material normal-weight geotechnical constraints on-site that cannot be mitigated by proper planning, design, [S0) percent by weight ratio, by weight, normal and light weight Type BNewport-Inglewood Fault. As such, the proposed development shall be designed in accordance with seismic considerations specified in the 2016 California Building Code (CBC) and and utilization of sound construction practices. The engineering properties of the soil weight concrete concrete, psirT the City of Newport Beach requirements. and native materials, and the surface drainage offer favorable conditions for site re- Negligible 0.00 s So,<0.10 0< s04<150 -- --- --- FA • Foundation specifications herein include added provisions for potential liquefaction on-site. development. [Si] Moderate 0.10<SO,<0.20 150<SO,< 1500 II,IP(MS), 0.50 4000 [S2i IS(MS),P(MS) SUMMARY OF RECOMMENDATIONS RECOMMENDATIONS I(PM)(MS), ch [ � E Design Item Recommendations I(SM)(MS) @,!J Foundations: The following sections discuss the principle geotechnical concerns which should be Severe o.zo < so,<z.00 1500<So4< v o.as asoo (0.) g g p g, p p g considered for ro er site re-develo ment. [S3] 10,000 Footing Bearing Pressure: 1,750 sf- buildin continuous; 2,250 sf- ad footin s P P P H Passive Lateral Resistence: 250 psf per foot Very Severe so,>2.00 So,> 10,000 V plus o.a5 asoo Perimeter Footing Widths: min. 15 inches with two No. 5 bars top and bottom Earthwork [S4) poaalan E Perimeter Footing Depths: min. 24 inches below lowest adjacent grade ® [) Coefficient of Friction: 0.30 b 00 Mat Slab (Optional): min. 12 inches with thickened edges (+ 6 inches) Grading and earthwork should be performed in accordance with the following As a conservative approach, we recommend cement with a minimum concrete V with no. 5 bars @ 12" o.c. each way, top and bottom recommendations and the General Earthwork and Grading Guidelines included strength f'c of 3,000 psi be used for concrete in contact with on-site earth I .(D+ Soil Expansion: Non-Expansive Beach Sands in Appendix C. It is our understanding that the majority of grading will be limited materials. U Soil Sulfate Content: Negligible Building Pad Removals: min. 2'/ ff. overexcavation to the re-grading of the building pad for the proposed construction. In general, � cw9 v Soil Maximum Density: 106.0 pcf at 12.0%Optimum Moisture Content it is anticipated that the removal of the upper 2'/z feet (plus 6 inches of Slabs-on-grade V� U Ca scarification) within the building footprint (slab-on-grade portion) will require tn% Building Slab: removal and recompaction to prepare the site for construction. The removals Concrete slabs cast against properly compacted fill materials shall be a ' Concrete slabs cast against properly compacted fill materials shall be a minimum of 5 inches should be accomplished so that all fill and backfill existing as part of the minimum of 5 inches thick (actual) and reinforced with No. 4 rebar at 12 inches ® � thick (actual) and reinforced with No. 4 rebar at 12 inches on center in both directions. previous site use and demolition operations are removed. on center in both directions. The slabs shall be doweled into the footings using Dowel all footings to slabs with No. 4 bars at 24 inches on center. No. 4 bars at 24 inches on center. The reinforcement shall be supported on ' co Concrete building slabs shall be underlain by 2"clean sand, underlain by a min. 15 mil thick moisture barrier, with all laps sealed, underlain by 4"of 3/4-inch gravel (capillary break). Where feasible, the limits of the pad fill shall be defined by a 2'/z feet envelope chairs to insure positioning of the reinforcement at mid-center in the slab. encompassing the building footprint. Care should be taken to protect the Interior slabs shall be underlain by 2 inches of clean sand over a min. 15 mil ® 24j Seismic Values (per CBC 2016,ASCE 7-10): adjacent property improvements. visqueen moisture barrier, with all laps sealed, over 4 inches 3% -inch crushed Site Class Definition (Table 1613.5.2) D rock (see "Capillary Break," below). Mapped Spectral Response Acceleration at 0.2s Period, Ss 1.709 g A minimum one foot thick fill blanket should be placed throughout the exterior I �) 4 Mapped Spectral Response Acceleration at 1s Period, S, 0.632 g improvements (approaches, parking and planter areas). The fill blanket will be Some slab cracking due to shrinkage should be anticipated. The potential for �l Short Period Site Coefficient Period, Fa 1.00 Long Period Site Coefficient att 1 s Period, F. 1.50 achieved by re-working (scarifying) the upper 12 inches of the existing grade. the slab cracking may be reduced by careful control of water/cement ratios. Adjusted Spectral Response Acceleration at 0.2s Period, SH,s 1.709 g The contractor should take appropriate curing precautions during the pouring of Adjusted Spectral Response Acceleration at 1s Period, S,1 0.948 g concrete in hot weather to minimize cracking of slabs. We recommend that a Design Spectral Response Acceleration at 0.2s Period, S 1.139 Site Preparation g p p os g slipsheet (or equivalent) be utilized if crack-sensitive flooring is planned directly Pq Design Spectral Response Acceleration at 1s Period, So, 0.632 g Prior to earthwork or construction operations, the site should be cleared of on concrete slabs. All slabs should be designed in accordance with structural PGAm= 0.703 g P considerations. surface structures and subsurface obstructions and stripped of any vegetation 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 642-9309 • FAx (949) 642-1290 in the areas proposed for development. Removed vegetation and debris should Capillary Break Below Interior Slabs then be disposed of off-site. A minimum of 2'/= feet of the soils below existing grade will require removal and recompaction in the areas to receive building pad In accordance with the 2016 California Green Building Standards Code Section V) fill. Following removal, the excavated surface should be inspected by the soils g LIQUEFACTION ANALYSIS (Per SP117A) engineer or his designated representative prior to the placement of any fill in 4.505.2.1, we provide the following building specification for the subject site The CPT testing was performed in accordance with the "Standard Test Method footing trenches. Holes or pockets of undocumented fill resulting from removal (living area and garages slabs): of buried obstructions discovered during this inspection should be filled with for Performing Electronic Friction Cone and Pie Penetration Testing suitable compacted fill. Concrete building slabs shall be directly underlain by a min. 2 inches of Soils," (ASTM D5778-12). The seismically inducceded settlement for the proposed clean/washed sand, underlain by a min.15 mil-thick moisture barrier (e.g. structure was evaluated based on the "Soil Liquefaction During Earthquakes" by Fills "Stego Wrap"), with all laps sealed, underlain by 4 inches of % -inch gravel. I.M. Idriss and R.W. Boulanger, dated September 8, 2008. The analysis was provided by one 10-feet deep 4 " diameter hand-auger The on-site soils are suitable for reuse as compacted fill, provided they are free The above specification meets or exceeds the Section 5.505.2.1 requirement. borings, and a 50'/z feet deep 1.7" diameter CPT probe advanced on October of organic materials, debris, and materials larger than six (6) inches in diameter. 26, 2018. The boring and probe locations are shown in the Plot Plan, Figure 2, After removal of any loose, compressible soils, all areas to receive fill and/or Settlement 0 U herein. other surface improvements should be scarified to a minimum depth of 12 inches, brought to at least 2 percent over optimum moisture conditions and Utilizing the design recommendations presented herein, we anticipate that thef�tt F The soil boring was continuously logged by a certified engineering geologist of compacted to at least 90 percent relative compaction (based on ASTM: D majority of any post-grading settlement will occur during construction activities. �4 1557). If necessary, We estimate that the total settlement for the our firm. ) ry, import soils for near-surface fills should be predominately proposed structure will be on the granular, possess a low or very low expansion potential, and be approved by order of 1 inch. Differential settlement is not expected to exceed 1 inch in 30 V) V) feet. These settlement values are expected to be within tolerable limits for The computations and results of our Liquefaction Analysis, based on CPT blow the geotechnical engineer. properly designed and constructed foundations. counts of Boring CPT-1, are attached Appendix E, herein. The seismically Lift thicknesses will be dependent on the size and type of equipment used. In induced settlement analysis was evaluated based on methods published in the Lateral Load Resistance � references Nos. "a" through "j" (see "Associated References", herein). The general, fill should be placed in uniform lifts not exceeding 8 inches. Placement liquefaction and seismic settlement calculations indicate seismic settlement and compaction of fill should be in accordance with local grading ordinances Includes d and saturated sands In the u under the observation and testing of the geotechnical consultant. We Footings founded in fill materials may be designed for a passive lateral bearing ( dry ) � peer h ( feet is less than m recommend that fill soils be placed at moisture contents at least 2 percent over pressure of 250 pounds per square foot per foot of depth. A coefficient of inches, and in the upper 10 feet less than th1. inch (post soil cement remedial optimum (based on ASTM: D 1557). friction against sliding between concrete and soil of 0.30 may be assumed. grading); and hence shallow mitigation methods for liquefaction may be implemented per City Code Policy (No. CBC 1803.5.11-2 last revised 7/312014). We recommend that oversize materials (materials over 6 inches) should they be New Garage Grade Beams Based on our liquefaction analysis, and in accordance with the Cityof Newport encountered, be stockpiled and removed from the site. P The grade beams, reinforced continuously with the garage footings, should be Beach Policy ati CBC hods t mini (ze the Chapter shallow o recommend the The on-site soils may be used as trench backfill provided they are screened of constructed across the garage entrance, tying together the ends of the garage following mitigative methods to minimize the effects of shallow liquefaction: grade beams should be embedded at the same depth as the The s. rock sizes over 6 inches in dimension and organic matter. Trench backfill footings. 1. Tie all pad footings with grade beams. should be compacted in uniform lifts (not exceeding 8 inches in compacted adjacent perimeter footings. The grade beams/thickened slab edges should �0 2. All footings should be a minimum of 24 inches deep, below grade. thickness) by mechanical means to at least 90 percent relative compaction consist of a clean, cold joint (disregard for monolithic pours). (ASTM: D 1557). 3. Continuous footings should be reinforced with two No. 5 rebar (two at the Exterior Slabs-on-grade (Hardscape) top and two at the bottom). Geotechnical Parameters 4. Concrete slabs cast against properly compacted fill materials shall be a Concrete slabs cast against properly compacted fill materials shall be a V) minimum of 5 inches thick (actual) and reinforced with No. 4 rebar at 12 The following Geotechnical parameters may used in the design of the proposed minimum of 4 inches thick (actual) and reinforced with No. 3 rebar at 18 inches W inches on center in both directions. The reinforcement shall be supported structure (also, see "Liquefaction Analysis" section, above): on center in both directions. The reinforcement shall be supported on chairs to on chairs to insure positioning of the reinforcement at mid-center in the insure positioning of the reinforcement at mid-center in the slab. slab. Foundation Design 5. Dowel all footings to slabs with No. 4 bars at 24 inches on center. Control joints should be provided at a maximum spacing of 10 feet on center in ® <� U 6. Additionally, for cohesion treatment of the site sand fills; soil-cement Structures on properly compacted fill may be supported by conventional, two directions for slabs and at 6 feet on center for sidewalks. Control joints are shall be used in the upper 2% feet. To achieve this, during grading - dry continuous or isolated spread footings. All footings should be a minimum of 24 intended to direct cracking. PQ bags of Portland Cement shall be mixed in the scarified over-excavation inches deep (measured in the field below lowest adjacent grade). Footing U bottoms and into each of the overlying fill lifts. Water via a 2-inch hose widths shall me an minimum 15 inches and 18 inches for interior beams and Expansion or felt joints should be used at the interface of exterior slabs on shall be vigorously induced during the ad grading operations. perimeter footings respectively. PQ PQ PQ 9 Y 9 p 9 9 Pgrade and any fixed structures to permit relative movement. The foundation specifications outlined above will act to decrease the potential At this depth (24 inches) footings founded in fill materials may be designed for �_, settlement due to liquefaction and/or seismically induced lateral deformation to an allowable bearing value of 1,750 and 2,250 psf(for dead-plus-live load) for This opportunity to be of service is appreciated. If you have any questions, please call. continuous wall and isolated spread footings, respectively. These values may 18 Balboa Coves,Newport Beach,CA be increased by one-third for loads of short duration, including wind or seismic Very truly yours, Soils Report-Martin Residence forces. Project No. Bs1n.1 EGA Consultants, Inc. November 30,2018 10 Continuous perimeter footings should be reinforced with No. 5 rebar (two at the ' top and two at the bottom). Reinforcement requirements may be increased if recommended by the project structural engineer. In no case should they be DAVID A. WORTHINGTON CEG 2124 JOHN F. EGGER DATE decreased from the previous recommendations. Principal Engineering Geologist �\SfEREOC Staff Geologist 3 - 20 - 2019 Mat Foundation Design (Optional) ko�/aq�°� PROJECTNO. bq 1%, gi 18 - 35 Due to anticipated high tide waters and cohesionless sands during construction, 0 eFfk? -mf S11EEI No. a mat slab foundation system is a recommended option. Mat slabs founded in �� FN°tt�n�'FO 4 compacted fill or competent native materials may be designed for an allowable peF°I FST°�t� }1 bearing value of 2,250 psf(for dead-plus-live load). These values may be Copies. (a) Addressee increased by one-third for loads of short duration, including wind or seismic forces. The actual design of the foundation and slabs should be completed by 375-C Monte Vista Avenue • Costa Mesa, CA 92627 • (949) 6 42-9 30 9 • FAx (949) 642-1290 the structural engineer.