HomeMy WebLinkAboutObservation of Excavation 12.20.2022K+AKumar &Associates, Inc.®
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@kumamsa.com
An Employee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
December 20, 2022
Ridge Runner Construction
Attn; Brent Lough
1655 County Road 109
Glenwood Springs, Colorado 81601
blrid gerunner(a`) email. com
Project No. 22-7-784
Subject: Observation of Excavation, Proposed Residence, Lot 68, Los Amigos Ranch,
Filing 5, Phase 2, Garfield County, Colorado
Dear Brent:
As requested, the undersigned representative of Kumar & Associates, Inc. observed the
excavation at the subject site on December 20, 2022, to evaluate the soils exposed for foundation
support. The findings of our observations and recommendations for the foundation design are
presented in this report. LKP Engineering, Inc. previously conducted a soil and foundation
investigation for design of foundations at the site and presented their findings in a report dated
June 29, 2022, Project No. 22-3628. Our observation was performed according to our agreement
for professional services with Ridge Runner Construction Dated December 20, 2022.
The proposed residence will be a one and two-story wood frame structure over a crawlspace.
The attached garage will have a slab -on -grade floor. Foundations were designed for an
allowable soil bearing pressure of 2,000 psf.
At the time of our visit to the site, the foundation excavation had been cut in three levels from 1
to 6 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of basalt rocks to boulder size in a whitish sandy silt matrix. No free water was
encountered in the excavation and the soils were slightly moist. The footing foundations were in
place and the foundation walls were formed. The bearing soils were visible on the inside and
outside of the footings. A thin layer of 3/ -inch road base sandy gravel had been placed in low
areas of the footing subgrade prior to forming footings. The fill areas appeared to have been
well -compacted.
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. The bearing soils should be protected from frost and concrete
should not be placed on frozen soils. Other recommendations presented in the previous report
which are applicable should also be observed.
The recommendations submitted in this letter are based on our observation of the soils exposed
in the foundation excavation, the previous limited subsurface exploration at the site by others and
our experience in the area. Variations in the subsurface conditions below the excavation could
Ridge Runner Construction
December 20, 2022
Page 2
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 &
Daniel E. Hardin,
Rev. by: SLPO,cr�•,,.�_N•�'�
DEH/kac
cc: Kaup Engineering — Dale Kaup (dale(a)kaupen ineering com)
Kumar & Associates, Inc.' Project No. 22-7-784