HomeMy WebLinkAboutObservation of Excavation 11.22.2021K+AGeotechnical and Materials Engineers 5020 County Road 154
and Environmental Scientists Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
An Employee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
November 22, 2021
Alius Design Group
Attn: Michael Edinger
108 Diamond A Ranch Road
Carbondale, Colorado 81623
michael(a aliusdc.com
Project No. 21-7-267
Subject: Observation of Excavation, Proposed Residence, Lot H6, The Homestead, Aspen
Glen Subdivision, 17 Spire Ridge, Garfield County, Colorado
Dear Michael:
As requested, the undersigned representative of Kumar & Associates, Inc. observed the
excavation at the subject site on November 18 and 22, 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 April 29, 2021, Project No.
21-7-267.
At the time of our initial visit to the site, the foundation excavation had been cut in one level
from 2%2 to 31/2 feet below the adjacent ground surface. The soils exposed in the bottom of the
excavation consisted of stiff, sandy silty clay. No free water was encountered in the excavation
and the soils were slightly moist to moist. Gravel soils were exposed in the deeper utility
trenches on the west side of the house footprint. We recommended via telephone to excavate
down to the gravel soils in footing areas according to our design recommendations.
We returned to the site on November 22, 2021 and observed that the excavation had been
deepened about a foot and gravel soils were observed throughout the excavation. The utility
trenches had been backfilled. It appeared that a few inches of the clay soil had been used in
some areas for fine grading the bottom of the excavation. We recommended that the subgrade be
moistened and compacted prior to forming footings.
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 2,500 psf. Loose and disturbed soils should be removed in the footing areas
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 should also be observed.
Alius Design Group
November 22, 2021
Page 2
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.
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 determining the presence, prevention or possibility of mold or other biological
contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a
professional in this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
Kumar & Associates, Inc.
Danis
Rev.
DEH,
Kumar & Associates, Inc. 11 Project No. 21-7-267