HomeMy WebLinkAboutObservation of ExcavationKumar & Associates, Inc. aD
K 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 Employee Owned Company www.kumarasa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
December 15, 2023
Norsk Builders
Attn: Chris Hjorth
norskbuilderski4mail.com
Project No. 17-7-787A
Subject: Observation of Excavation, Proposed Residence, Lot 23, Stirling Ranch, Skipper
Drive and Schooner Lane, Garfield County, Colorado
Dear Chris:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on December 6, 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 conducted a subsoil study for design of foundations at the site and
presented our findings in a report dated December 11, 2017, Project No. 17-7-787.
The residence will be a one and two-story wood frame structure over a partial basement/partial
crawlspace with slab -on -grade in the basememt and garage. 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 two levels up to 10
feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of mostly silty sand with basalt rocks The soils exposed in the shallower, west end of
the building area consisted of sandy silt and clay. 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 suitable for support of spread footings designed for the recommended allowable
bearing pressure of 2,000 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
Norsk Builders
December 15, 2023
Page 2
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
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.
Daniel E.
DEH/kac
Kumar & Associates, Inc. 0 Project No.17-7-787A