HomeMy WebLinkAboutObservation of Excavation 09.05.2014IIEPWORTH-PAWLAK GEOTECHNICAL
September 5, 2014
Ty Rice
P.O. Box 398
Carbondale, Colorado 81623
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SEP 01,.;2014
GARFIELD COUNTY
)MMUNITY DEVELOPMENT
Job No. 114 123A
Subject: Observation of Excavation, Proposed Residence, 268 Rose Lane, Garfield
County, Colorado
Dear Mr. Rice:
As requested, a representative of Hepworth-Pawlak Geotechnical, Inc. observed the
excavation at the subject site on September 5, 2014 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 April 25,
2014, Job No. 114 123A.
The proposed residence will be one story wood frame above a crawlspace.
At the time of our visit to the site, the foundation excavation had been cut in one level
from 2Y2 to 3 feet below the adjacent ground surface. The soils exposed in the bottom of
the excavation consisted of silty sandy gravel with cobbles and boulders. Groundwater
was encountered at the footing grade and a 3 inch to 6 inch layer of %-inch screened rock
had been placed over the granular soils.
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 2,500 psf. Loose and disturbed soils should
be compacted in the footing areas as needed. Due to the shallow groundwater level, a
moisture barrier should cover the crawlspace grade and the crawlspace area should be
well vented to prevent excessive humidity. 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
Parker 303-841-7119 • Colorado Springs 719-633-5562 • Silverthorne 970-468-1989
Ty Rice
September 5, 2014
Page 2
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,
HEPWORTH — PAWLAK GEOTECHNICAL, INC.
Louis E. Eller
Reviewed by:
Steven L. Pawlak, P.E.
LEE/ksw
Job No. 114 123A
Gtech