HomeMy WebLinkAboutCIVIL SHEET 3 OF 3 CONCLUSIONS Cement Type for Concrete in Contact with On-Site Earth Materials PRE-CONSTRUCTION MEETING
Based on our geotechnical study of the site, our review of available reports and g g It is recommended that no clearing of the site or an grading operation be performed without Site: Proposed Custom Home: 6311 Seashore Drive
Concrete mix design should be based on sulfate testing with Section 1904.2 of g y g g P P Newport Beach.California
literature and our experience, it is our opinion that the proposed improvements at the the 2016 CBC. Preliminary laboratory testing indicates the site soils possess the presence e a representative a this office. ad on site pre-grading meeting should be
site are feasible from a geotechnical standpoint. There appear to be no significant arranged between the soils engineer and the grading contractor prior to any construction.
g p p 9 negligible sulfate exposure. executive Summary
geotechnical constraints on-site that cannot be mitigated by proper planning, design, ACI 318-14 BUILDING CODE GEOTECHNICAL OBSERVATION AND TESTING DURING CONSTRUCTION
and utilization of sound construction practices. The engineering properties of the soil ale 1g.3.1.1-REQUIREMENTS FOR CONCRETE EXPOSED TO SULFATE-CONTAINING SOLUTIONS Based on our geotechnical study of the site, our review of available reports and literature and our
offer favorable conditions for site re- T b experience, it is our opinion that the proposed residential development is feasible from a geotechnical
and native materials, and the surface drainagesoluble sulfate so)in cement Type Maximum water- Minimum fd, We recommend that a qualified geotechnical consultant be retained to provide geotechnical standpoint. There appear to be no significant geotechnical constraints on-site that cannot be mitigated by
Sulfate wares ( • cementitious material normal-weight engineering services, including geotechnical observation/testing, during the construction phase proper planning, design,and utilization of sound construction practices. The engineering properties of the
development. Exposure sulfate(so,)m eon water,ppm 9 9 9 9 9 9 P P P 9 9 P 9 9
(sol percent by weight ratio,by weight,normal and lightweight of the project. This is to verify the compliance with the design, specifications and or soil and native materials,and surface drainage offer favorable conditions for site re-development.
RECOMMENDATIONS weight concretencrete concrete,psi
recommendations, and to allow design changes in the event that subsurface conditions differ
--- ""- The following key elements are conclusions confirmed from this investigation:
Negligible 0.00, So,<0.10 o s so,<150 --- from those anticipated.
The following sections discuss the principle geotechnical concerns which should be (Si]
Moderate 0.1D<SO,<0.20 150<so,<150o II,IP(MS), 11.50 a000 Geotechnical observations/testing should be performed at the following stages: A review of available geologic records indicates that no active faults cross the subject property.
considered for proper site re-development. s(1.1pro ), The site is located in the seismically active Southern California area,and within 2 kilometers of the
[$21 (PM)(MS), Type B Newport-Inglewood Fault. As such,the proposed development shall be designed in
Earthwork I(SM)(MS) During ANY grading operations, including excavation, removal, filling, compaction, accordance with seismic considerations specified in the 2016 California Building Code(CBC)and
and backfilling, etc. the City of Newport Beach requirements.
Severe 0.20 <so,<2.00 1500<sg,< v o.a5 4500 After excavations for footings(or thickened edges) and/or grade beams verify the Foundation specifications herein include added provisions for potential liquefaction on-site.
Grading and earthwork should be performed in accordance with the following (sal 10,000
recommendations and the General Earthwork and Grading Guidelines included adequacy of underlying materials.
Very Severe so,>z.00 so,>10,00o v plus o.a5 asoo After pre-soaking of new slab sub-grade earth materials and placement of SUMMARY OF RECOMMENDATIONS
in Appendix C. It is our understanding that the majority of grading will be limited [sal poualan capillary break, plastic membrane, prior to pouring concrete.
to the re-grading of the building pad for the proposed construction. In general, During backfill of drainage and utility line trenches, to verify proper compaction. Design Item Recommendations
it is anticipated that the removal of the upper 2'/2 (+6 inches of scarification) As a conservative approach, we recommend cement with a minimum concrete When/if any unusual geotechnical conditions are encountered.
feet within the buildingfootprint (slab-on-grade portion)will require removal and Prior to all slab pours to ensure proper subgrade compaction and moisture Foundations:
P ( 9 P ) q strength f c of 3,000 psi be used for concrete in contact with on-site earth
recompaction to prepare the site for construction. The removals should be materials. — — — - - — barriers. Footing Bearing Pressure 250
psf-building,continuous; 2,25°psf-pad footings
Passive Lateral Resistance
accomplished so that all fill and backfill existing as part of the previous site use — — psf per foot
min
Perimeter Footing Widths: min. 15 inches with two No. 5 bars top and bottom
and demolition operations are removed. Settlement Please schedule an inspection with the geotechnical consultant prior to the Perimeter Footing Depths: min.24 inches below lowest adjacent grade
pouring of ALL interior and exterior slabs. Coefficient of Friction 0.30
Mat (Optional): min. 12 inches with thickened away,(+8 inches)
Where feasible, the limits of the pad fill shall be defined by a 3 feet envelope Utilizing the design recommendations presented herein, we anticipate that the
with no.5 bars @ 12"o.c. each way,top and bottom
encompassing the building footprint. Care should be taken to protect the majority of any post-grading settlement will occur during construction activities. LIMITATIONS Soil Expansion Non-Expansive Beach Sands
adjacent property improvements. We estimate that the total settlement for the proposed structure will be on the Soil Sulfate Content Negligible,[So]
order of 1 inch. Differential settlement is not expected to exceed 1 inch in 30 The geotechnical services described herein have been conducted in a manner consistent with the level of Building Pad Removals: min. 2% ft.overexcavation(+6 inches of scarification)
A minimum one foot thick fill blanket should be placed throughout the exterior feet. These settlement values are expected to be within tolerable limits for care and skill ordinarily exercised by members of the geotechnical engineering profession practicing
improvements (approaches, parking and planter areas). The fill blanket will be contemporaneously under similar conditions in the subject locality. Under no circumstance is any Building Slab:
p ( pp p g p ) properly designed and constructed foundations. warranty,expressed or implied, made in connection with the providing of services described herein. Data,
achieved by re-working (scarifying) the upper 12 inches of the existing grade. P P 9 Concrete slabs cast against properly compacted fill materials shall r i a minimum of 5 inches
interpretations, and recommendations presented herein are based solely on information available to this thick(actual)and reinforced with No.4 rebar at 12 inches on center in both directions.
Lateral Load Resistance office at the time work was performed. EGA Consultants will not be responsible for other parties' ' Dowel all footings to slabs with No.4 bars at 24 inches on center.
Site Preparation interpretations or use of the information developed in this report. ` Concrete building slabs shall be underlain by 2"clean sand, underlain by a min. 15 mil thick
Footings founded in fill materials may be designed for a passive lateral bearing moisture barrier,with all laps sealed,underlain by 4"of a/,-inch gravel(capillary break).
Prior to earthwork or construction operations, the site should be cleared of pressure of 250 pounds per square foot per foot of depth. A coefficient of The interpolated subsurface conditions should be checked in the field during construction by a
p p p q P P representative of EGA Consultants. We recommend that all foundation excavations and grading Seismic Values(per CBC 2018,ASCE 7-10):
surface structures and subsurface obstructions and stripped of any vegetation friction against sliding between concrete and soil of 0.30 may be assumed. operations be observed by a representative of this firm to ensure that construction is performed in Site Class Definition(Table 1613.5.2) D
in the areas proposed for development. Removed vegetation and debris should accordance with the specifications outlined in this report.
Mapped Spectral Response Acceleration at 0.2s Period, S. 1.8922 g
then be disposed of off-site. A minimum of 2Yz feet (plus 6 inches scarification) Slabs-on-grade
We do not direct the contractor's operations,and we cannot be responsible for the safety of others. The Mapped Spectral Response Acceleration at 1 s Period, S, g
of the soils below existing grade will require removal and recompaction in the Short Period Site Coefficient at 0.2 Period, Fe 1.00
areas to receive buildingad fill. Following removal, the excavated surface Concrete slabs cast against properly compacted fill materials shall be a contractor should notify the owner if he considers any of the recommended actions presented herein to be Long Period Site Coefficient at is Period, Fv 1.50
p 9 9 P P Y P unsafe.
should be inspected by the soils engineer or his designated representative prior minimum of 5 inches thick (actual) and reinforced with No. 4 rebar at 12 inches Adjusted Spectral Response Acceleration at 0.2s Period, 0.939 g
Adjusted spectral Response Acceleration at 1s Period, S
to the placement of any fill in footing trenches. Holes or pockets of on center in both directions. The slabs shall be doweled into the footings using o,, 1. g
Design Spectral Response Acceleration at 0.2s Period, Spa .128128 g
undocumented fill resulting from removal of buried obstructions discovered No. 4 bars at 24 inches on center. The reinforcement shall be supported on Design Spectral Response Acceleration at 1s Period, Sp, 0.826 g
during this inspection should be filled with suitable compacted fill. chairs to insure positioning of the reinforcement at mid-center in the slab. PGAm=0,692 g
Interior slabs shall be underlain by 2 inches of clean sand over a min. 15 mil
Fills plastic vapor barrier, with all laps sealed, over 4 inches %-inch crushed rock
(see"Capillary Break," below). HARRIS RESIDENCE
The on-site soils are suitable for reuse as compacted fill, provided they are free
of organic materials, debris, and materials larger than four(4) inches in Some slab cracking due to shrinkage should be anticipated. The potential for c/o: Eric Olsen, AIA
diameter. After removal of any loose, compressible soils, all areas to receive fill the slab cracking may be reduced by careful control of water/cement ratios. 2728 E. Coast Highway, Suite "A"
and/or other surface improvements should be scarified to a minimum depth of The contractor should take appropriate curing precautions during the pouring of Corona Del Mar, CA 92660
12 inches, brought to at least 2 percent over optimum moisture conditions and concrete in hot weather to minimize cracking of slabs. We recommend that a
compacted to at least 90 percent relative compaction (based on ASTM: D slipsheet (or equivalent) be utilized if crack-sensitive flooring is planned directly Subject: GEOTECHNICAL INVESTIGATION
1557). If necessary, import soils for near-surface fills should be predominately on concrete slabs. All slabs should be designed in accordance with structural FOR PROPOSED RESIDENTIAL DEVELOPMENT
granular, possess a low or very low expansion potential, and be approved by considerations. LOCATED AT
the NE SEASHORE DRIVE
_geotechnical engineer. _
Lift thicknesses will be dependent on the size and type of equipment used. In Capillary Break Below Interior Slabs NEWPORT BEACH, CALIFORNIA
general, fill should be placed in uniform lifts not exceeding 6 inches. Placement
In accordance with the 2016 California Green Building Standards Code Section ear Eric eta ,
and compaction of fill should be in accordance with local grading ordinances 4.505.2.1, we provide the following building specification for the subject site
under the observation and testing of the geotechnical consultant. We In accordance with your request, we have completed our Geotechnical Investigation of
recommend that fill soils be placed at moisture contents at least 2 percent over (living area and garages slabs): the above referenced site. This investigation was performed to determine the site soil
optimum (based on ASTM: D 1557). Concrete building slabs shall be directly underlain by a min. 2 inches of conditions and to provide geotechnical parameters for the proposed residential
We recommend that oversize materials (materials over 4 inches) should they be clean/washed sand, underlain by a min.15 mil-thick moisture barrier (e.g. development at the subject site.
encountered, be stockpiled and removed from the site. "Stego Wrap"), with all laps sealed, underlain by 4 inches of %-inch gravel. Based on our discussions, the proposed development shall include the demolition of
We do not advise placing sand directly on the gravel layer as this would the existing site structures, and the construction of a new residential dwelling with an
The on-site soils may be used as trench backfill provided they are screened of reverse the effects of vapor retardation (due to siltation of fines).
attached garage and associated improvements,
rock sizes over 4 inches in dimension and organic matter. Trench backfill The above specification meets or exceeds the Section 4.505.2.1 requirement.
should be compacted in uniform lifts (not exceeding 8 inches in compacted This report presents the results of the investigation (including Liquefaction
thickness) by mechanical means to at least 90 percent relative compaction New Garage Grade Beams Computations) along with grading and foundation recommendations pertaining to the
(ASTM: D 1557). re-development of the subject lot.
The grade beams, reinforced continuously with the garage footings, should be
Soil Cement constructed across the garage entrance, tying together the ends of the garage This opportunity to be of service is appreciated. If you have any questions, please call.
footings. The grade beams should be embedded at the same depth as the
Due to in situ dry sands, we recommend approximately four(4) pallets (35 bags
dry mix, each weighing 94 pounds and approximately 1.33 cubic yards) of adjacent perimeter footings. The grade beams/thickened slab edges should Very truly yours,
consist of a clean, cold joint (disregard for monolithic pours).
Portland cement be blended into the newly-placed fill. The first application of EGA Consultants, Inc.
Exterior Slabs-on-grade (Hardscape)the Portland Cement shall be placed on the bottom of the scarified over- CK
excavation(s). This option may be eliminated or reduced if suitable import fills
are trucked-in. Concrete slabs cast against properly compacted fill materials shall be a bAVID F. EGGERS
minimum of 4 inches thick (actual) and reinforced with No. 3 rebar at 18 inches 4 J HN
Geotechnical Parameters Principal Engineering Geologis Z,1EpEDpFO Staff Geologist
on center in both directions. The reinforcement shall be supported on chairs to
insure positioning of the reinforcement at mid-center in the slab. Q� womil" * 'n gQF` �EH//��C�sJ
The following Geotechnical parameters may used in the design of the proposed
structure (also, see "Liquefaction Analysis" section, above): Control joints should be provided at a maximum spacing of 10 feet on center in * CEG212q w A gL
two directions for slabs and at 6 feet on center for sidewalks. Control joints are �1g �
w' 6weuv(u' o N�.
Foundation Design l Le
intended to direct cracking, �F` °t°c)sr # r./ter':
Copies. (3) Addressee C•F CALtF sT9 y,,,�,,,,rpL^F ,iJ
Structures on properly compacted fill may be supported by conventional, Expansion or felt joints should be used at the interface of exterior slabs on E gF
continuous or isolated spread footings. All footings should be a minimum of 24 grade and any fixed structures to permit relative movement. '
inches deep (measured in the field below lowest adjacent grade). Footing
widths shall me an minimum 15 inches and 16 inches for interior beams and Some slab cracking due to shrinkage should be anticipated. The potential for
perimeter footings respectively. the slab cracking may be reduced by careful control of water/cement ratios.
At this depth 24 inches footings founded in fill materials may be designed for The contractor should take appropriate curing precautions during the pouring of
p ( ) 9 Y 9 concrete in hot weather to minimize cracking of slabs.
an allowable bearing value of 1,750 and 2,250 psf(for dead-plus-live load)for
continuous wall and isolated spread footings, respectively. These values may Surface Drainage
be increased by one-third for loads of short duration, including wind or seismic
forces. Surface drainage shall be controlled at all times. Positive surface drainage
Continuous should be reinforced with No. 5 rebar(two footings perimeter at the should be provided to direct surface water away from structures and toward the
P 9 — street or suitable drainage facilities. Ponding of water should be avoided
top and two at the bottom). Reinforcement requirements may be increased if adjacent to the structures. Recommended minimum gradient is 2 percent for
recommended by the project structural engineer. In no case should they be unpaved areas and one percent for concrete/paved areas. Roof gutter ,V9'IJ
decreased from the previous recommendations. discharge should be directed away from the building areas through solid PVC
pipes to suitable discharge points. Area drains should be provided for planter
Mat Foundation Design (Optional) areas and drainage shall be directed away from the top of slopes. 7
Due to cohesionless sands during construction, a mat slab foundation system is Review of Plans
a recommended option. Mat slabs founded in compacted fill or competent V
native materials may be designed for an allowable bearing value of 2,250 psf The specifications and parameters outlined in this report shall be consideredirfS/�
(for dead-plus-live load). These values may be increased by one-third for loads minimum requirements and incorporated into the Grading, Foundation, Ej� 1• UU /\�
of short duration, including wind or seismic forces. The actual design of the Landscape, Pool/Spa and Shoring plans if applicable. This office should review
foundation and slabs should be completed by the structural engineer. the Plans when available. If approved, the geotechnical consultant shall Na, 2466R
sign/stamp the applicable Plans from a geotechnical standpoint.
MIN. DESIGN ITEM RECOMMENDATIONS ar
Mat foundations:
allowable bearing pressure: 1,000 psf C/Vll �4
passive lateral resistence: 250 psf per foot
mat slab thickness: min. 12 inches with thickened edges(+6 inches) C
steel reinforcement: no. 5 bars @ 12"o.c.each way,top and bottom A S OILT S REPORT
coefficient of friction. 0.30
Modulus of Subgrade Reaction: k, = 1001bslin3 PREPARED BY :
SOILS ENGINEER : PROPERTY OWNER : BENCHMARK : DUCA-McCOY, INC. RECOMMENDATIONS
EGA CONSULTANT- CHIP&SHAWN HARRIS ESTABLISHED TOP OF CURB ELEVATION ON FOR
375-C MONTE VISTA AVE. 5311 SEASHORE DRIVE 54TH STREET AT THE NORTHEASTERLY CORNER 3840 E.COAST HIGHWAY 5 311 SEASHORE DRIVE
COSTA MESA,CA 92627 OF THIS PROPERTY. CORONA DEL MAR,CA 92625 �-1
PH: 949-642-1290 NEWPORTBEACH,CA 92663 ELEVATION= T.C. 11.53TBM (949)675 4487 NEWPORT BEACH, CA
949-375-3690 (TMB TAKEN FROM TOPOGRAPHIC SURVEY PROVIDED
BY OTHERS) PETE i.DUCA R.C.E.24668 DATE LOT 6,BLOCK 53 OF THE OCEANFRONT TRACT SHEET 3 OF 3