HomeMy WebLinkAboutObservation of Excavation 05.31.2024
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 (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
May 31, 2024
Janckila Construction
Attn: Alex Janckila
75 Buckskin Drive
Carbondale, Colorado 81623
alex@janckilaconstruction.com
Project No. 23-7-522.A
Subject: Observation of Excavation, Proposed Westerfield Residence, Lot H17, Filing 7,
Aspen Glen, 15 Horseshoe Lane, Garfield County, Colorado
Dear Alex:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 28, 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 October 4, 2023, Project No. 23-7-522.
We understand the proposed residence to be of wood frame construction with ground floors
being structural over crawlspace in the residence and a slab-on-grade in the garage. The building
foundation is designed for an allowable soil pressure of 1,500 psf.
At the time of our visit to the site, the foundation excavation had been cut in one level from
about 1½ feet to 4 feet below the adjacent ground surface. The soils exposed in the bottom of
the excavation consisted of relatively stiff sandy silt and clay. Results of swell-consolidation
testing performed on samples taken from the site, shown on Figure 1, indicate the soils have
low compressibility under light loading and existing moisture conditions, and low to moderate
compressibility under conditions of loading and wetting. No free water was encountered in
the excavation and the soils were slightly 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 and disturbed soils should be removed in the footing areas
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
Kumar & Associates