HomeMy WebLinkAboutObservation of Excavation 11.26.13HEPWORTH-PAWLAK GEOTECHNICAL
November 26, 2013
Ridge Runner Construction
Attn: Brent Lough
1655 County Road 109
Glenwood Springs, Colorado 81601
(blridgerunner(gmail.com)
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Job No. 113 346A
Subject: Observation of Excavation, Proposed Golf Pro Shop Addition, 410
Ironbridge Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Hepworth-Pawlak Geotechnical, Inc. observed the
excavation at the subject site on November 25, 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 October
25, 2013, Job No. 113 346A.
The addition will be attached to the west side of the pro shop building with a basement
and be about 5 feet away from the sales office building which is supported by a spread
footing bearing at a depth of 4 feet. Spread footings sized for an allowable bearing
pressure of 1,500 psf were designed for foundation support of the building addition.
At the time of our visit to the site, the foundation excavation had been cut in one level
from 9 to 15 feet below the adjacent ground surface. The cut along the existing footing of
the sales office building was about 4 feet deep. The west wall footing of the pro shop
building was exposed in the north part of the wall and probing by hand encountered the
top of footing about 4 to 6 inches below cut depth in the south part. The soils exposed in
the bottom of the excavation consisted of silty to clayey gravelly sand with scattered
cobbles. No free water was encountered in the excavation and the soils were moist to
very moist from recent precipitation. Roof runoff had been flowing into the south side of
the excavation causing softening and mud in footing areas. The footing forms were being
placed at the time of our site visit.
The soil conditions exposed m 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 1,500 psf with a risk of settlement. The soils
in the footing areas should be compacted. It is critical that the surface water flow into the
excavation be diverted away from the excavation and any softened soils and mud in
footing areas be removed before concrete placement. The bearing soils should be
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Ridge Runner Construction
November 26, 2013
Page 2
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 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 conditions for possible changes to reconunendations 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 G.�':� "irG!. ICAL, INC.
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Steven L. Pawlak, P.E. 1 5 2 2 2 e*
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cc: Kaup Engineering — ' (katipeng a,rof.net)
Job No. 113 346A
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