HomeMy WebLinkAboutObservation of Excavation
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
email: kaglenwood@kumarusa.com
www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
April 15, 2025
Brad Crawford
brad.cdb@gmail.com
Project No. 22-7-506
Subject: Observation of Excavation, Proposed Residence, Lot M46, Roaring Fork Mesa,
Aspen Glen Subdivision, Garfield County, Colorado
Dear Mr. Crawford:
As requested, Kumar & Associates observed an undated photo of the excavation at the subject
site which was taken prior to placement of concrete for footings. The purpose of this letter is to
evaluate the soils exposed for foundation support based on our experience in the area. Our
recommendations for the foundation support are presented in this report.
We understand that the foundations were designed for an allowable soil bearing pressure of
2,500 psf.
The soils exposed in the excavation appear to consist of silty sand gravel with cobbles. At the
time of our visit to the site, the foundation excavation had been cut in three levels from 2 to 6
feet below the adjacent ground surface. No free water was encountered in the excavation and
the soils were slightly moist.
Considering the conditions exposed in the excavation and the nature of the proposed
construction, spread footings placed on the undisturbed natural soil designed for an allowable
soil bearing pressure of 2,500 psf should be adequate for support of the proposed residence.
Continuous foundation walls should be reinforced top and bottom to span local anomalies such
as by assuming an unsupported length of at least 10 feet. Foundation walls acting as retaining
structures should also be designed to resist a lateral earth pressure based on an equivalent fluid
unit weight of at least 45 pcf for on-site soil as backfill. A perimeter foundation drain should be
provided to prevent temporary buildup of hydrostatic pressure behind the basement walls and
prevent wetting of the lower level. Structural fill placed within floor slab areas can consist of the
on-site soils or a suitable imported material compacted to at least 95% of standard Proctor