HomeMy WebLinkAboutObservation of Excavation 11.23.21
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
November 23, 2021
Sigi Marioni
198 Comanchero Trail
New Castle, Colorado 81647
sigi.marioni@gmail.com
Project No. 20-7-744.01
Subject: Observation of Excavation, Proposed Residence, Lot 17-A, Mineota Ridge
Estates, Mineota Drive, Garfield County, Colorado
Dear Sigi:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on November 17, 2021 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 February 26, 2021, Project No. 20-7-744.
The proposed construction is similar to that discussed in our previous report. The building has
been designed to be supported on spread footings using an allowable soil bearing pressure of
2,000 psf as recommended.
At the time of our visit to the site, the foundation excavation had been cut in 4 levels from 2 to
4 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of stiff, sandy clay with gravel. Results of swell-consolidation testing performed on a
clay sample taken from the site, shown on Figure 1, indicate the soils have low to moderate
compressibility under conditions of loading and wetting. No free water was encountered in the
excavation and the soils were slightly 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 2,000 psf. Loose and disturbed soils in the footing areas should be moistened
and compacted or removed to expose the undisturbed natural soils. 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, especially those to keep the bearing soils
dry, 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