HomeMy WebLinkAboutObservation of ExcavationKumar & Associates, Inc. 11
'f Geotechnical 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 Employ" Owrwpd Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
July 8, 2024
Burkholder Homes
Attn: Todd Burkholder
P.O. Box 400
Carbondale, Colorado 81623
todd@burkholderhomesinc.com
e Project No. 20-7-610.A
Subject: Observation of Partial Excavation, Proposed Residence, Lot S5, Filing 8, Aspen
Glen, 589 Saddleback Road, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on July 3, 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 November 12, 2020, Project No. 20-7-610. The current observation
was performed in accordance with our agreement for professional services with Burkholder
Homes dated July 2, 2024.
The proposed residence will be above a basement level and designed to be supported on spread
footings placed on compacted structural fill and sized for the recommended allowable bearing
pressure of 2,000 psf.
At the time of our visit to the site, the foundation excavation was in progress and had been cut
in 2 levels from about 7 to 10 feet below the adjacent ground surface. The soils exposed in the
bottom of the excavation mainly consisted of sandy silty clay. Gravel and cobbles were exposed
in the bottom of the uphill, northwestern excavation area about 10 feet deep and about 3 feet
lower than the eastern excavation area. The garage area which will have shallow cut depth had
not been excavated. No free water was encountered in the excavation and the soils were slightly
moist
to moist.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and can be used for support of spread footings placed on at least 3 feet of compacted
structural fill or on the natural gravel soils designed for the recommended allowable bearing
pressure of 2,000 ps£ A lower settlement risk alternative would be to sub -excavate the clay soils
down to the gravel and replace the onsite material or road base as compacted structural fill to
design bearing level. We should observe the completed excavation and evaluate compaction of
the structural fill during placement on a regular basis. Other recommendations presented in our
previous report which are applicable should also be observed.
Burkholder Homes
July 8, 2024
Page 2
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
or possible changes to the 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.
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Steven L. Pawlak, P.
ASS/ONALE��
Kumar & Associates, Inc. 0 Project No. 20-7-610.A