HomeMy WebLinkAboutObservation of Excavation 06.20.2023
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
June 20, 2023
Palomino Design Build
Attn: Jack Palomino
919 Palmer Avenue
Glenwood Springs, Colorado 81601
jackpalomino55@gmail.com
Project No. 22-7-707
Subject: Observation of Excavation, Proposed Addition to Detached Garage, Tankersley
Residence, 2068 County Road 137, Garfield County, Colorado
Dear Jack:
As requested, a representative of Kumar & Associates observed the excavation at the subject site
on November 2, 2022 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations are presented in this report. The services were performed in
general accordance with our agreement for professional services to Palomino Design Build dated
November 1, 2022.
The addition will be attached to the west side of the existing garage. The addition has been
designed to be supported on spread footings and pads sized using an allowable soil bearing
pressure of 3,000 psf. The foundation design was based on a previous subsoil study for the
residence at the site by Hepworth-Pawlak Geotechnical dated July 29, 1999, Job No. 199 512.
At the time of our site visit, the foundation excavation had been cut in one level from about 2 to
4 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted primarily of relatively dense, silty sandy gravel and cobbles. In the southwest portion
of the excavation, a shallow depth of fill was observed overlying the natural dense coarse
granular soils. At this time, we recommended removal of the fill, which we understand and
based on pictures provided to us, was done. The results of a gradation analysis performed on a
disturbed bulk sample of natural coarse granular soils (minus 3-inch fraction) obtained from the
site are presented on Figure 1. No groundwater was encountered in the excavation and the soils
were 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 assumed allowable
bearing pressure of 3,000 psf. Loose and disturbed soils should be removed in the footing areas
to expose the undisturbed natural coarse granular soils and the subgrade compacted. Other
recommendations presented in the previous Hepworth-Pawlak Geotechnical 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 limited subsurface exploration at the site.
Kumar & Associates