HomeMy WebLinkAboutObservation of Excavation 09.24.2024
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
September 24, 2024
Transwest Construction
Attn: Mike Scrivens
P. O. Box 2325
Gypsum, Colorado 81637
mike@transwestconstruction.com
Project No. 24-7-124.01
Subject: Observation of Excavation, Proposed Residence, Lot D-24, Aspen Glen, 52 Elk
Track Lane, Garfield County, Colorado
Dear Mike:
As requested, a representative of Kumar & Associates observed the excavation at the subject site
on September 11, 2024 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations are presented in this report. The services are supplemental to
our agreement for professional services to Transwest Construction dated January 23, 2024.
We previously prepared a subsoil study for design of foundations at the site and presented our
findings in a report dated March 25, 2024, Project No. 24-7-124. The proposed construction is
similar to that discussed in our previous report. The building has been designed to be supported
on spread footings sized using an allowable soil bearing pressure of 1,500 psf as recommended
with some risk of movement.
At the time of our site visit, the foundation excavation which was essentially complete had been
cut in one level from about 1 to 2½ feet below the adjacent ground surface. The soils exposed
in the bottom of the excavation consisted primarily of stiff, sandy to very sandy silty clay with
scattered gravel. In the crawlspace excavation area just south of the attached garage area, a zone
of silty clayey sand and gravel was exposed at subgrade. Results of swell-consolidation testing
performed on samples taken from the site, shown on Figures 1 and 2, indicate the silty clay soils
are moderately to highly compressible under conditions of loading and wetting with a low to
moderate hydro-compression potential. The samples may have been partly disturbed due to the
sampling process and/or rock content. No free water was encountered in the excavation and the
soils were slightly 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 designed for the
recommended allowable bearing pressure of 1,500 psf. The soils are not expansive. The risk
of settlement is if the bearing soils were to become wetted, and precautions should be taken to
prevent wetting. Prior to the footing construction, all loose disturbed soils should be removed
in to expose the undisturbed natural soils, and the subgrade moistened and compacted. Other
recommendations presented in our previous report which are applicable should also be observed.
Kumar & Associates
Kumar & Associates