HomeMy WebLinkAboutObservation of Excavation 03.17.2023
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
March 17, 2023
Russell Cartwright
542 Meadow Creek Drive
Parachute, Colorado 81635
russecart@gmail.com
Project No. 22-7-669.01
Subject: Observation of Excavation, Proposed Residence, Lot 16, Block 7, Willow Creek
Section 1, 16 Ridge View Place, Garfield County, Colorado
Dear Russell:
As requested, a representative of Kumar & Associates observed the excavation at the subject site
on March 10, 2023 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations are presented in this report. The services are supplemental to
our agreement for professional services to you dated October 4, 2022.
We previously conducted a subsoil study for design of foundations at the site and presented our
findings in a report dated December 5, 2022, Project No. 22-7-669. 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, as recommended
with some risk of settlement.
At the time of our site visit, the foundation excavation which was essentially complete had been
cut in one level from ½ to 3½ feet below the adjacent ground surface. There was minor cut in
the garage slab area. The soils exposed in the bottom of the excavation consisted of generally
stiff, sandy to very sandy silt. Results of swell-consolidation testing performed on samples taken
from the site, shown on Figure 1, indicate the soils are moderately to highly compressible with a
moderate hydro-compression potential. The sample may have been partly disturbed due to the
sampling process. No free water was encountered in the excavation and the soils were moist to
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 an allowable bearing pressure
of 1,500 psf. The risk of settlement is primarily if the bearing soils were to become wetted and
precautions should be taken to prevent wetting. Prior to the footing construction, all loose soils
should be removed in the footing areas to expose the undisturbed natural soils, and the subgrade
moistened and 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
Kumar & Associates