HomeMy WebLinkAboutObservation of Excavation 04.27.2022I ($rt irffii,f.tr*fÉH¡,yËü
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An Employca Owncd 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 (TìQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit Corurty, Colorado
April27,2022
Don Reboul
P.O. Box 994
New Castle, Colorado 81647
donreboulconstruction@ gmai l.com
Project No. 2l-7-688
Subject: Observation of Excavation, Proposed Residence, Lot 4, On-Smith Subdivision,
County Road 312, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on April 19, 2022to 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 December 1, 2021, Project No. 2l-7-688.
The proposed residence is essentially the same as described in our previous report and has been
designed to be supported on spread footings sized for the recommended allowable bearing
pressure of 1,500 psf.
At the time of our visit to the site, the foundation excavation had been cut in 3 levels from I to
1% feet below the adjacent ground surface. The soils exposed in the bottom ofthe excavation
consisted of stiff to very stiff, sandy silty clay. Results of swell-consolidation testing performed
on a sample taken from the site, shown on Figure 1, indicate the soils are slightly to moderately
compressible under conditions of loading and wetting. No free water was encountered in the
excavation and the soils were slightly moist to 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 1,500 psf. Loose disturbed soils in the footing areas should be moistened and
compacted or removed to expose the undisturbed natural soils. Other recommendations
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
Don Reboul
April27,2022
Page2
(MOBC) developing in the firture. If the client is concerned about MOBC, then aprofessional in
this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
Kurnar & Assocíntes, Inc.
Steven L. Pawlak, P
SLP/kac
Attachment:Figure I -Test Results
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Kumar & Assoclates, lnc. ñ'Projeel No. 21"7-688
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SAMPLE OF: Sondy Silty Cloy
FROM: Bottom of Excovotion Wesl Side
WC = 17.2 %, DD = 108 pcf
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1.0 APPLIED PRESSURE _f0 100
21 -7 -688 Kumar & Associates SWELL-CONSOLIDATION TEST RESULTS Fig. 1