HomeMy WebLinkAboutObservation of Excavation Report 10.14.2013October 14, 2013
Crawford Design Build, LLC
Attn: Brad Crawford
P.O. Box 1236
Carbondale, Co lorado 81623
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Job No. 113 278A
Subject: Observation of Excavation, Proposed Residence, Lot I2, Callicotte Ranch,
Garfield County, Colorado
Dear Mr. Crawford:
As requested by Seth Crawford, a representative of Hepworth-Pawlak Geotechnical, Inc.
observed the excavation at the subject site on October 11, 2013 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
August 12, 2013, Job No. 113 278A.
The proposed residence will be one and two story wood frame construction and consists
of an upper living area and lower living area above a walkout level.
At the time of our visit to the site, the upper foundation excavation had been cut in one
level and the lower area had been cut in two levels. The step between levels was about 6
to 8 feet. The upper level had been cut from I to 10 feet below the adjacent ground
surface and the lower level had been cut from 1 to 6 feet below grade. The soils exposed
in the bottom of the excavation consisted of basalt cobbles and boulders in a sandy clay
and silt matrix. 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 in the
footing areas should be compacted or removed to expose the undisturbed natural soils.
The bearing soils should be protected from frost and 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 Ietter are based on our observation of the soils
exposed within the foundation excavation and the previous limited subsurface exploration
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Crawford Design Build, LLC
October 14, 2013
Page 2
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.
Ifyou have any questions or need further assistance, please call our office.
Sincerely,
HEPWORTH - PAWLAK GEOTECHNICAL, INC.
Reviewed by:
Steven L. Pawlak, P.E
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Job No. 113 278A
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