HomeMy WebLinkAboutObservation of Excavation 05.23.2022Assecleft, hic. -
K+A&KWW
Geotedmical 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
May 23, 2022
Cody and Karla Ferguson
P.O. Box 792
Silt, Colorado 81652
cf masoM i ,yahoo.com
Project No. 22-7-127.A
Subject: Observation of Excavation, Proposed Residence, Lot 6, Mineota Estates,
2674 Mineota Drive, Garfield County, Colorado
Cory and Karla:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 12, 2022 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 February 24, 2022, Project No. 22-7-127.
The proposed residence design and location are essentially the same as described in our previous
report. We understand the design alternative of providing at least 3 feet of road base gravel
below footings was selected to avoid designing the foundation for expansive soils and minimum
dead load pressure presented in our previous report.
At the time of our visit to the site, the foundation excavation had been cut in 2 levels from about
4 to 11 feet below the adjacent ground surface. The natural soils exposed in the bottom of the
excavation consisted of very stiff to hard sandy clay with clayey sand lenses. Road base
placement was in progress along the perimeter footing areas. No free water was encountered in
the excavation and the soils were slightly moist to moist. We returned to the site on May 13 and
determined 3 in -place densities on the road base at footing grade. The density values were
134.8, 134.2 and 134.7 pcf which, in our opinion, meet the minimum 98% of standard Proctor
density.
The clay soils exposed in the excavation are consistent with those previously encountered on the
site and the compacted road base is suitable for support of spread footings designed for the
recommended allowable bearing pressure of 2,500 psf. Other recommendations presented in our
previous report which are applicable, including keeping the bearing soils dry, 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
Cody and Karla Ferguson
May 23, 2022
Page 2
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.
Steven L. Pawlak,
SLP/kac
Kumar & Associates, Inc. '£ Project No. 22-7-127.A