HomeMy WebLinkAboutObservation of Excavation 04.09.2024I(+A#ffi1fi'#trffiniiri'*"
An Ernploysg otryncd GomFony
5020 CountY ltoad 154
Glenwor:d SPrings, CO 81601
phone: f970) 945-7t)88
fax: {970) 945-8454
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Oflice t ocations: Dsnver (l-lQ), Parker, Calorado Springs, Fort Collins'Clenwood Springs, altcl Suntmit Counfy. (lolorado
Apil9,2A24
Boulder Construction Services
Attn: Matt Jurmu
901 county Road 231
Silt, Colorado 81652
Matt j urrnufrlhgulderqs "co Project No. 20-7-167.,4.
Subject: Observation of Excavation, Proposed Detached Addition, Lot 67 Spring Ridge
Reserve. 542 Hidden valley Drive, Garfield county, colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on April 8, 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 March 79,2A20, Project No. 20-7-167.
The proposed building will be single-story above crawlspace. Spread footings placed on the
natural soils and sized for the recommended allowable bearing pressure of 1,500 psf were
designed for the foundation support.
At the time of our visit to the site, the foundation excavation had been cut in one level from
about 2 to 3yzfeet below the adjacent ground surface. The soils exposed in the bottom of the
excavation consisted of stiff, sandy silty clay with slight porosity apparently from fine roots'
No free water was encountered in the excavation and the soils were slightly moist.
The soil conditions exposed in the excavation are consistent with those previously encountered
o' the site and can be used for support of spread footings designed for the recommended
allowable bearing pressure of 1,500 psf with a settlement risk. The soils tend to settle when
wetted and precautions should be taken to keep the bearing soils dry' Loose disturbed soils
should be rernoved in the footing areas and the exposed soils moistened and compacted. Due
to the shallow crawlspace depth and moisture sensitive nature of the bearing soils, a perimeter
foundation drain should not be provided. Other recomrnendations presented in our previous
repofi which are applicable, especially those to compact perimeter wall backfill and slope the
surface away from the foundation 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 (limited) 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
Boulder Construction Services
Apil9,2024
Page2
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 & Assoeiates,
Steven L. Pawlak, P.
SLPikac
a 5222
Kumar & Associates, lnc. @ Project No.20-7-167.A