HomeMy WebLinkAboutObservation of Excavation 10.28.2024Kumar & Associates, Inc.
K Geotechnical and Materials Engineers 5020 County Road 154
and Environmental Scientists Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
An Employee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
October 28, 2024
Kent Olson
P.O. Box 455
Rifle, Colorado 81650
kent(cr�,k5-construction.com
Project No. 21-7-356.A
Subject: Observation of Excavation, Proposed Residence, 2607 County Road 314, Garfield
County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on October 22, 2024 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 September 4, 2024, Project No. 21-7-356A.
The proposed residence is located in the area of Boring 1 of our previous report and has been
designed to be supported by spread footings placed on the natural soils and sized for an
allowable bearing pressure of 1,500 psf with a risk of settlement.
At the time of our visit to the site, the foundation excavation had been cut in one level from
about 1 to 3 feet below the adjacent ground surface. The soils encountered in the bottom of the
excavation consisted of very silty sand with root holes in the shallower cut, south part. We
understand the excavation bottom was left 1/2-foot high and 1/2-foot of Class 6 base course was
proposed to be placed and compacted below footing areas. No free water was encountered in
the excavation and the soils were slightly moist to moist.
The soil conditions exposed in the excavation are generally consistent with those previously
encountered on the site and suitable for support of spread footings including '/2-foot of
compacted base course designed for the recommended allowable bearing pressure of 1,500 psf
with a risk of settlement mainly if the native bearing soils are wetted. Loose disturbed soils in
the footing areas should be moistened and compacted. 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 limited 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 the recommendations contained in this letter. Our services
Kent Olson
October 28, 2024
Page 2
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.
Sincerely,
Kumar & Associates, Inc. pp0 REG,
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Steven L. Pawlak, P.
SLP/kac ��SS/ONALENI
Kumar & Associates, Inc. 0 Project No. 21-7-356.A