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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 9, 2024
Christopher Tezanos
2636 Panorama Drive
Carbondale, Colorado 81623
christophertezanos@gmail.com
Project No. 24-7-280
Subject: Observation of Excavation, Proposed Steel Building, 2636 Panorama Drive,
Garfield County, Colorado
Dear Christopher:
As requested, a representative of Kumar & Associates observed the excavation at the subject
site on May 1, 2024 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations for the foundation support are presented in this report. The
services were performed in accordance with our agreement for professional engineering services
to Christopher Tezanos dated May 1, 2024.
The propsoed building will be a steel frame metal skin structure with a footprint of
approximately 40 by 60 feet. The building has been designed to be supported on spread footings
sized for an allowable bearing pressure of 1,500 psf assumed by the structural engineer.
At the time of our visit to the site, the foundation excavation had been cut in one level from 3
to 5 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of dense, gravel and cobbles in a sandy silt caliche matrix on the east side of the
excavation and dense, sandy clayey gravel and cobbles on the west side of the excavation.
The results of a gradation analysis performed on a sample of clayey and silty sandy gravel and
cobbles (minus 3-inch fraction) obtained from the site are presented on Figure 1. No free water
was encountered in the excavation and the soils were slightly moist to 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 1,500 psf should be adequate for support of the proposed building.
The matrix soils tend to compress when wetted and there could be some post-construction
settlement of the foundation if the bearing soils become wet. Footings should be a minimum
width of 16 inches for continuous walls and 2 feet for columns. Loose disturbed soils in footing
areas should be removed and the bearing level extended down to the undisturbed natural soils.
Exterior footings should be provided with adequate soil cover above their bearing elevations for
frost protection. Continuous foundation walls should be well reinforced top and bottom to span
local anomalies such as by assuming an unsupported length of at least 12 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 50 pcf for on-site soil as backfill. Structural fill placed
Kumar & Associates