HomeMy WebLinkAboutObservation of Excavation 06.12.24Kumar & 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
June 12, 2024
Lauren Vance
3194 County Road 226
Silt, Colorado 81652
lauren(a,truenorthcolorado.com
Project No. 23-7-117
Subject: Observation of Excavation, Proposed Shop Building, 3194 County Road 226,
Garfield County, Colorado
Lauren:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on June 11, 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 August 23, 2023, Project No. 23-7-117.
The proposed shop building is designed for spread footings placed on the bedrock and sized for
the recommended allowable bearing pressure of 4,000 psf with a risk of movement due to the
expansion potential of the weathered shale.
At the time of our visit to the site, excavation for the perimeter foundation and 3 exterior pads
had been made in one level from about 2 to 3'h feet below the adjacent ground surface and
exposed weathered claystone-shale in the excavation bottom. No free water was encountered
in the excavation and the bedrock was moist.
The bedrock condition exposed in the excavation is consistent with that previously encountered
on the site and can be used for support of spread footings designed for the recommended
allowable bearing pressure of 4,000 psf with a risk of post -construction movement. Loose
disturbed material should be removed in the footing areas to expose the natural bedrock. 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
(MOBC) developing in the future. If the client is concerned about MOBC, then a professional
in this special field of practice should be consulted.
Lauren Vance
June 12, 2024
Page 2
If you have any questions or need further assistance, please call our office.
Sincerely,
Kumar & Assc
Steven L. Pav
SLP/kac
Kumar & Associates, Inc. 0 Project No. 23-7-117