HomeMy WebLinkAboutObservation of ExcavationKumar & 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 Employ" Uwned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
March 26, 2025
Cleary Building Corporation
Attn: Tyler Mize
715 A Hwy 50, Delta, Colorado 81647
tmize(&clegn building.com Project No. 22-7-503
Subject: Observation of Excavations, Proposed Pole Barn, 405 Mid Valley Road near
New Castle, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates observed the excavation at the subject
site on July 18, 2022 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations for the foundation support are presented in this report. The
services were performed in accordance with our agreement for professional engineering services
to Cleary Building Corporation dated July 15, 2022.
We understand the proposed pole barn has been designed to be founded on an isolated pier
foundation and sized assuming an allowable bearing pressure of 1,500 psf.
At the time of our visit to the site, the foundation pier holes had each been cut in one level each
to a depth of about 5 feet below the adjacent ground surface. The soils exposed in the bottom of
the excavations consisted of silty sandy gravel and cobble soils. The upper soils exposed in the
floor slab area consisted of stiff, very sandy clay. About 1 foot of compacted 3/-inch aggregate
base course had been placed for support of the floor slab. Laboratory testing on a sample of
the upper fine-grained soils from the site showed a percent -finer -than -sand size gradation of
60 percent, a liquid limit of 36 and a Plasticity Index of 17. No free water was encountered in
the excavation and the soils were slightly moist.
Considering the conditions exposed in the excavations and the nature of the proposed
construction, a pier foundation placed on the undisturbed natural soil designed for an allowable
soil bearing pressure of 1,500 psf can be used for support of the proposed pole barn. Loose and
disturbed soils in pier and floor slab areas should be removed and the bearing level extended
down to the undisturbed natural soils. Exterior footings should be provided with adequate soil
cover above their bearing elevations for frost protection. Structural fill placed within floor slab
areas can consist of the on -site soils or aggregate base course compacted to at least 95% of
standard Proctor density at a moisture content near optimum. Backfill placed around the
structure should be well compacted and the surface graded to prevent ponding within at least
10 feet of the building.
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavations and do not include subsurface exploration to evaluate the
Cleary Building Corporation
March 26, 2025
Page 2
subsurface conditions within the loaded depth of foundation influence. This study is based on
the assumption that soils beneath the footings have equal or better support than those exposed.
The risk of foundation movement may be greater than indicated in this report because of possible
variations in the subsurface conditions. In order to reveal the nature and extent of variations in
the subsurface conditions below the excavation, drilling would be required. It is possible the
data obtained by subsurface exploration could change the 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.
Sincerely,
Kumar & Associ;
Robert L. Duran, I
Rev. by: DAY
RLD/kac
cc: William DuBois (ham.d8(a�hotmail.com)
Kumar & Associates, Inc. 0 Project No. 22-7-503