HomeMy WebLinkAboutObservation of Excavationrcn f,.ifrf;:ffi,ffin'"nr;**-
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An Emdolto Orrnod ComPonY
5020 County ltoad 154
Glcnwood liprings. CO 81601
phone: (970) S45-7988
fax: (970) 945-8454
enrail : kaglenwood(lkttmanrsa,corn
www-.kumarusa. com
Office tncations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Clenwotxl Sprirtgs, antl Sumrni t Cbunty, C-olorado
J,ily 19,2o24
Smith Mountain Builders
Attn: Eric Mason
1011 Heritage Drive
Carbondale, Colorado 81 623
smi thmourrtai nbui lders@smail'com
Project No. 20-7-537.A
Subject Observation of Excavation, Proposed Residence, 1515 Elk Springs Drive, Lot73,
Los Amigos Filing 7, Garfreld County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on July 15, 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 Octob er 26,2020, Project No. 20-7-537 . The observations were
performed in accordance with our agreement for geotechnical engineering services to Smith
Mountain Builders dated July 11,2024.
At the time of our initial visit to the site, the basement level was being excavated. We visited
the site four days later and observed the excavation had been completed. The foundation
excavation had been cut in multiple levels from 4 to 10 feet below the adjacent ground surface'
The soils exposed in the bottom of the excavation consisted of basalt rocks in a calcareous matrix
in the deeper portions of the excavation and sandy silty clay soil in the shallower parts of the
excavation. No free water was encountered in the excavation and the soils were slightly moist
to moist. Some loose soil was observed in the lower, basement area of the excavation. This
material should be removed below footing areas or moistened and compacted if below slab areas.
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. Some loose and disturbed soils were observed in the southern
basement area. The loose soils should be removed from below footing areas to expose the
undisturbed natural soils. In below-slab areas, the loose soils can be iemoved or moistened
and compacted. 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 conditiohs below the excavation could increase the risk of foundation
movement. We should be advised of any variations encountered in the excavation conditions