HomeMy WebLinkAboutObservation of Excavation 06.04.24l GA Hiffilfl'ffifflt:fn'"'rd
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An Employee Owned Compony
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email : kaglenwood@kumarusa.com
www.kumarusa.com
Office Locations: Denver (HQ), Parkeq Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
June 4,2024
Spillane Custom Construction
Attn: Steve Spillane
264Buckthorn Road
New Castle, Colorado 81647
spillanes@hotmail.com Project No.24-7-328
Subject: Interim Findings of Excavation Observation, Proposed Residence,7l0l County
Road I17, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 24,2024 to evaluate the soils exposed for foundation support. The findings
of our observations and preliminary recommendations for the foundation design are presented in
this report. The observation was performed according to our agreement for professional services
to Spillane Custom Construction dated May 24,2024.
The existing residence has been removed and a new residence is planned in its place. Spread
footings placed on the natural soils are tentatively assumed for the foundation support.
At the time of our visit to the site, the building area had been stripped of debris and topsoil and
was around % to lYz feet below the adjacent ground surface along the uphill, south side. The
soils exposed in the bottom of the excavation consisted of medium stiff sandy silty clay. Two
shallow pits were dug at the west side and southeast corner for additional information which
showed clay soil to pit depths of about 3 feet. Results of swell-consolidation testing performed
on a sample taken from the site, shown on Figure l, indicate the upper clay soils are moderately
compressible under conditions of loading and wetting. The results of an unconfined compressive
strength indicate soft to medium stiff consistency. The laboratory test results are summarized in
Table l. Free water was encountered in the southeast comer pit at a depth of about 2 feet below
the building cut depth. The upper soils were moist to very moist.
The soil conditions exposed in the excavation are consistent with those expected in the creek
bottom arcaand lightly loaded spread footings designed for an allowable bearing pressure of
aroundEUUpsIcanbeaSSumedforprellmlnaryloundat,on,upp
$rE?ffiaseparationfilterfabricsuchasMirafi140N(orheavier)mayneedtobe
placed on the subgrade covered with around one foot of CDOT Class 6 road base to achieve a
stable working platform for the foundation construction. When development plans are better
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The recommendations submitted in this letter are based on our observation of the soils exposed
within the building excavation and do not include subsurface exploration at the site. Variations
Spillane Custom Construction
June4,2024
Page2
in the subsurface conditions below the excavation could increase the risk of foundation
movement. We should be advised of any variations encountered in the excavation conditions
for possible changes to recommendations contained in this letter. Our services do not include
determining the presence, prevention or possibility of mold or other biological contaminants
(MOBC) developing in the future. If the client is concerned about MOBC, then a professional
in this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerelyo
Kumar & Associates, lnc
Steven L. Pawlak, P
SLP/kac
Attachments: Figure 1-Test Results
Table I - Summary of Laboratory Test Results
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Kumar & Associates, Inc. @ Proiect No, 24-7-328
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TABLE 1
SUMMARY OF LABORATORY TEST RESULTS
Project No.24-7-328
SAMPLE LOCATION
NATURAL
MOISTURE
CONTENT
lohl
NATURAL
DRY
DENSITY
lDcf)
GRADATION
PERCENT
PASSING NO.
200 stEVE
AT'I G I IMITS
UNCONFINED
COMPRESSIVE
STRENGTH
IPSF)
solL oR
BEDROCK TYPE
BOTTOM OF EXCAVATION
GRAVEL
f/")
SAND
fhl LIQUID LIMIT
t:h\
PLASTIC
INDEX
t%l
Wesl" Side 20.8 104 Sandy Silty Clay
Southeast Comer 25.3 93 36 550 Sandy Silty Clay with
Gravel