HomeMy WebLinkAboutObservation of Excavation 05.09.2023
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
May 9, 2023
DM Neuman Construction
Attn: Jarrid Hadland
P.O. Box 2317
Glenwood Springs, Colorado 81602
jh@dmneuman.com
Project No. 20-7-693.01
Subject: Observation of Excavation, Proposed Addition, Lot 19, Four Mile Ranch,
18 Sunrise Court, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 5, 2023 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 provided recommendations for design of foundations at the site for an addition to
the residence in 2020 and presented our findings in a report dated November 16, 2020, Project
No. 20-7-693. The current observation was performed in accordance with our agreement for
professional services to DM Neuman Construction dated May 3, 2023.
The proposed addition will be attached to the east side of the residence and be supported by
spread footings sized for an assumed allowable bearing pressure of 1,500 psf.
At the time of our visit to the site, the foundation excavation had been cut in one level about 2
feet deep next to the residence and about 3 feet deep at the proposed isolated pad just south of
the addition. The soils exposed in the bottom of the excavation consisted of sandy silty clay
which was moist next to the residence and slightly moist at the isolated pad excavation. Results
of swell-consolidation testing performed on a sample of the moist clay taken from the site,
shown on Figure 1, indicate the soils are slightly to moderately compressible under conditions of
loading and wetting.
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 assumed allowable
bearing pressure of 1,500 psf with a risk of settlement mainly if the bearing soils are wetted.
Loose disturbed soils should be removed in the footing areas to expose the undisturbed natural
soils. A foundation drain is not needed with proper backfill compaction and surface grading
away from the building. 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 soils identified at the site. Variations in the
subsurface conditions below the excavation could increase the risk of foundation movement. We
Kumar & Associates