HomeMy WebLinkAboutObservation of Excavation 04.01.24
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
April 1, 2024
Puma Paw, LLC
Attn: John Hilderbrant
1793 County Road 219
Rifle, Colorado 81650
Jhilderbrant42@gmail.com
Project No. 23-7-190
Subject: Observation of Excavation, Proposed Residence, 1793 County Road 219, Garfield
County, Colorado
Dear John:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on March 12, 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 June 8, 2023, Project No. 23-7-190.
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 based on recommendations provided in our report, with some risk of settlement.
At the time of our visit to the site, the foundation excavation had been cut in one level from 4
to 6 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of stiff/medium dense, very sandy silt to very silty sand with gravel. The results of a
gradation analysis performed on a sample of very sandy silt (minus ¾-inch fraction) obtained
from the site are presented on Figure 1. No free water 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 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 and the soils compacted. The bearing soils should be
protected from frost and concrete should not be placed on frozen 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
for possible changes to recommendations contained in this letter. Our services do not include
Kumar & Associates