HomeMy WebLinkAboutX2017-1171 - Soils (2)COAST GEOTECHNICAL, INC.
1200 West Commonwealth Avenue, Fullerton, CA 92833 Ph:714-870-1211 Fax:714-870-1222 e-mail:coastgeotec@sbcglobal.net
May 7, 2019
Mr. Kevin Moriarty
2782 Bayshore Drive
Newport Beach, CA 92663
References:
W.O. 551818-03
VO
PV Ral Shore Dr
Subject: Final Soils Report for 2772 Bayshore Drive,
Newport Beach, California
1. Preliminary Soils Report, Proposed Pool House at 2772 Bayshore Drive, Newport Beach,
California, by EGA Consultants, LLC, dated August 30, 2016.
2. Acceptance of Geotechnical Responsibility for Proposed Pool House at 2772 Bayshore Drive,
Newport Beach, California, by COAST GEOTECHNICAL, INC., W.O. 551818-01, dated March
21, 2018.
3. Rough Grade Compaction Report for Proposed Pool House at 2772 Bayshore Drive, Newport
Beach, California; by COAST GEOTECHNICAL, INC., W.O. 551818-02, dated March 23, 2018.
Dear Mr. Moriarty:
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.
SWIMMING POOL BOTTOM EXCAVATION
The pool excavation was observed on March 26, 2018. Probing and testing of the pool
excavation indicated acceptable geotechnical conditions for support of the proposed pool.
FOUNDATION EXCAVATIONS
Foundation excavations for the pool house were observed on April 10, 2018 and May 14, 2018.
The foundation excavations were found to be acceptable at the time of our final observations.
SLAB SUBGRADE AND TRENCH BACKFILL
The pool house slab subgrade and interior trench backfill were observed on May 18, 2018.
Probing and testing of the interior residential slab and trench backfill areas indicated acceptable
geotechnical conditions for support of the proposed slabs.
COAST GEOTECHNICAL, INC.
Mr. Moriarty 2 W.0.551818-03
Final Soils Report May 7 2019
HARDSCAPE
Hardscape subgrades of the patios, pavers, front entry; and driveway areas were observed on
April 6, 2018, March 18, 2019, March 22, 2019, April 1, 2019, April 24, 2019 and April 25,
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.
Ming-Tarng Chen
RCE 54011
No. 54/011
Exp. 12/31/19
CIV
COAST GEOTECHNICAL, INC.
1200 W. Commonwealth Ave., Fullerton, CA 92833 Ph: (714) 870-1211 Fax: (714) 870-1222 E-mail: coastgeotec@sbcglobal.net
March 23, 2018 W.O. 551818-02
Mr. Kevin Moriarty
2782 Bayshore Drive
Newport Beach, CA 92663
Subject: Rough Grade Compaction Report for
Proposed Pool House at 2772 Bayshore
Drive, Newport Beach, California
References:
1. Preliminary Soils Report, Proposed Pool House at 2772 Bayshore Drive, Newport Beach,
California, by EGA Consultants, LLC, dated August 30, 2016.
2. Acceptance of Geotechnical Responsibility for Proposed Pool House at 2772 Bayshore Drive,
Newport Beach, California, by COAST GEOTECHNICAL, INC., W.O. 551818-01, dated March
21, 2018.
Dear Mr. Moriarty:
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
pool house consisted of over -excavation and recompaction to provide uniformly compacted fill
soils for support of the residence, pool and hardscape. The grading operation was conducted
between March 15 and March 20, 2018. The project included upgrading the existing bulkhead
with a new deadman and tight backs installed by Shellmakers.
PLACEMENT OF FILL
Compacted fill material was placed to provide adequate support for proposed structures.
Over -excavation of the pool area, building pad and rear patio area extended into competent
material. The depth of over -excavation was about four to seven feet below original grade. A
buried structure was encountered in the proposed pool area and slot -cut excavations were
necessary along the western property line in order to remove the concrete and rubble below the
proposed structures. Some of the existing concrete rubble remains and extends below the
adjacent property to the west. The exposed surface was scarified, moisture conditioned and
compacted to a minimum of 90% relative compaction. All fill soils were blended with Portland
cement to provide improved stability during foundation and pool excavations. Final grade is near
original grade.
COAST GEOTECHNICAL, INC.
Mr. Moriarty 2 W.O. 551818-02
Rough Grade Compaction Report March 23. 2018
The rear patio area remains about two feet low and may be backfilled using spoils generated
from foundation excavations. Backfill soils shall be moisture conditioned and compacted to a
minimum of 90% relative compaction.
Subsequent fills were placed in six to eight inch loose lifts and compacted to a minimum of 90%
by track rolling. This process was followed to final grade.
Limits of grading are shown on the attached Plate 1.
Equipment used for the compaction of the fill soils consisted of a Kubota SVL90 rubber track
loader. Soils were moisture conditioned by a fire 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
SorlCtP
ifuurn Moisture,
:
3
�: Max ry Density; lbs
Iype_lassaf4cauon
o
I
Light Gray Clean Sand
10.0
112.0
Gray / Brown Silty Sand w/
II
10.0
115.0
Cement
III
Brown Silty Sand w/ Cement
9.5
120.0
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 an ASTM test
method. The test results are summarized in Table 1. The approximate test locations are shown on
Plate 1. Areas not tested were probed to show adequate compaction.
FOUNDATIONS ON GRADE
The proposed structures may be supported by continuous spread footings only, placed a
minimum depth of 24 inches below lowest adjacent grade. The foundation may utilize an
allowable bearing value of 1,750 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 foundations should be reinforced with at least four #5 bars, two top and two bottom and
follow structural engineers requirements.
COAST GEOTECHNICAL, INC.
Mr. Moriarty 3 W.O. 551818-02
Roueh Grade Compaction Report March 23, 2018
The foundation 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 .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 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.
POOL RECOMMDATIONS
The pool shall be supported by compacted fill in all areas. The pool should be designed as a
freestanding structure. Pool walls should be designed to support the water, having a density of
62.4 pounds per cubic foot without bearing from the adjacent soil. The walls should be able to
support the adjacent backfill soil when the pool is empty. The active earth pressure may be
calculated as an equivalent fluid pressure of 100 pcf, plus the lateral pressure due to any
superimposed surcharge when the pool is empty.
The pool excavation shall be observed and approved by COAST GEOTECHNICAL, Inc., prior
to steel placement.
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 one sack slurry. COAST GEOTECHNICAL, Inc. shall verify the backfill of
all trenches.
EXPANSIVE SOILS
Results of expansion tests indicate that the near surface soil at the completion of grading has a very
low expansion potential.
FLOOR SLABS
The concrete slab on grade area shall be at least 5 inches thick supported on engineered fill
compacted to a minimum of 90% relative compaction. Slabs should be reinforced with #4 bars at
12 inches on center each way.
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. Moriarty 4 W.O. 551818-02
Rough Grade Compaction Report March 23, 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. The City of Newport
Beach requires the use of four inches of gravel (1/2 -inch or larger clean aggregate). The capillary
break shall be covered with a heavy filter fabric (Mirafi 140N) 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
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. Since the vapor barrier will prevent moisture from draining from
fresh concrete, a better concrete finish can usually be obtained if at least two inches of sand is
spread over the vapor barrier prior to placement of concrete.
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. Minimum drainage shall be one percent
for hardscape areas and two percent for landscape areas.
Site waters shall not be allowed to drain in an uncontrolled manner. Waters shall be collected
and dispersed of in a manner in accordance with governing guidelines. Bottomless trench drain
to contain runoff on-site should not be located within five feet of foundations. Run-off should be
directed to approved areas.
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 pool and foundations
• Backfill of interior slab areas
• Backfill of interior trenches
• Backfill of exterior utility trenches
• Hardscape subgrade
COAST GEOTECHNICAL, INC.
Mr. Moriarty 5 W.O. 551818-02
Rough Grade Compaction Report March 23 2018
It is the responsibility of the developer to schedule the required observations and testing.
REGULATORY COMPLLANCE
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.
Q,ofESSIn
QUO R G,
Ming-Tarng Chen �� C� p N c �F2 4amel
RCE 54011 ; tim z Staff Geologist
w No, 54011 Z m
c Exp. 12/31/19 a
COAST GEOTECHNICAL, INC.
Mr. Moriarty 6 W.O. 551818-02
Rough Grade Compaction Report March 23, 2018
COMPACTION TEST RESULTS
TABLE 1
est
NoYade:(fl}'
I ocatxon
'Below'.-,;,-
Prtrposccl'.
; iVIaisture
Content
Dry Uxut
weight
, So
Relative
Co�npactior
Date
1
I
Pool Area
6.57.0
11.4
105.9
II
92.1
3/15/18
2
Pool Area
4.0-4.5
12.1
106.1
II
92.2
3/15/18
Pool Area
4.0-4.5
1 9.5
106.4
II
1 92.5
3/15/18
4
Slot -Cut Pad
ea
4.0-4.5
12.7
104.8
II
91.1
3/15/18
5
Slot-CCnett Pad
3.0-3.5
11.2
105.3
II
91.6
3/15/18
6
Pool Area
2.53.0
9.5
105.6
II
91.9
3/16/18
7
Pool Area
2.0-2.5
11.9
106.7
II
92.8
3/16/18
8
Hardscape Area
4.0-4.5
10.5
106.4
II
92.5
3/16/18
9
Pool Area
1.52.0
10.9
109.8
I1I
91.5
3/16/18
10
Pad Area
4.0-4.5
12.5
103.0
I
92.0
3/19/18
11
Pad Area
4.0-4.5
12.4
102.5
I
91.5
3/19/18
12
Hardscape Area
3.0-3.5
12.0
110.2
III
91.8
3/19/18
13
Pad Area
0.51.0
9.0
110.3
III
91.9
3/19/18
14
Pad Area
1.52.0
12.1
105.6
II
91.8
3/19/18
15
Hardscape Area
2.0-2.5
11.7
105.1
II
91.4
3/19/18
16
Pad Area
0.51.0
9.3
105.8
II
92.0
3/19/18
17
Hardscape Area
2.0-2.5 1
10.5
106.1
II
92.3
3/19/18
18
Pad Area
3.54.0
11.5
102.5
I
91.5
3/20/18
19
Pad Area
2.0-2.5
13.1
106.0
II
92.1
3/20/18
20
Pad Area
1.52.0
13.4
105.4
II
91.7
3/20/18
21
Pad Area
F.G.
13.2
106.0
II 1
92.2
3/20/18
22
Pad Area
F.G.
11.0
107.0
II
93.0
3/20/18
23
Pool Area
F.G.
11.5
107.2
II
93.2
3/20/18
F.G. =Finish Grade
SITE PLAN
Scale 1" = 20,
kpproximate
"ompaction
Pest Location
Approximate
Limits of Grading
Roug Grade Compaction Report Work Order 551818-02
2772 Bayshore Drive
Newport Beach, California Plate No. 1
COAST GEOTECHNICAL, INC.