HomeMy WebLinkAboutObservation of Excavation 11.25.2020l(-trt$ffir,ffii'#'å*"
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November 25,2020
RM Construction
Attn: Blake Piland
5030 County Road 154
Glenwood Springs, Colorado 81601
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Project No. 20-7-157
Subject: Observation of Excavation, Proposed Residence, Lot IS-12, Filing 2, Aspen Glen,
l2 Columbine, Garfield County, Colorado
Gentlemen:
As rquested by Jason Norris, a representative of Kumar & Associates, Inc. observed the
excavation at the subject site on Novemb er 20, 2020 to evaluate the soils exposed for foundation
support. The findings of our observations and recommendations for the foundation design are
presented in this report. We previously conducted a subsoil study for design of foundations at
the site and presented our findings in a report dated March 10,2020, Project No. 20-7-157.
At the time of our visit to the site, the foundation excavation had been cut in I level from l|/zto
3Yz feet below the adjacent ground surface. The soils exposed in the bottom ofthe excavation
consisted of very stifi sandy silty clay. Results of swell-consolidation testing performed on a
sample of the clay taken from the site, shown on Figure l, indicate the soils have low to
moderate compressibility (without expansion) under conditions of loading and wetting. No free
water was encountered in the excavation and the soils were slightly moist.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and suitable for support of spread footings designed for the recommended allowable
bearing pressure of 2,000 psf. Loose disturbed soils should be removed in the footing areas to
expose the undisturbed natural soils. The bearing soils should be protected from frost and
concrete should not be placed on frozen soils. Other recoürmendations presented in our previous
report which are applicable should also be observed.
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and the previous subsurface exploration at the site. Variations
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
RM Construction
November 25,2020
PageZ
{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.
Sincerely,
Kurnar & Associates, fnc.
Steven L. Pawlak, P
SLPlkac
Attachment: Figure 1-Test Results
Kumar & Associates, lnc.Project No, 20.7-157
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SAMPLE OF: Sondy Silty Cloy
FROM: Bottom of Excovotion Soulh End
WC = 6.1 %, tÐ = 98 pcf
to
h
ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
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T¡J
=tft
t*z
zotr
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oanz.oo*1
-5
PRESSURE - KSF
20-7-157 Kumar & Associates SWTLL_CONSOLIDATION TEST RESULT Fig. 1
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