HomeMy WebLinkAboutObservation of Excavation Report 09.21.15~ech
HEPWORTH-PAWLAK GEOTECHNICAL
September 21, 2015
Dave and Judy Douglas
9 Navajo
New Castle, Colorado 81647
riverbum@ opris.net
Hepworth-l'awlnk Georechnical, Inc.
5020 County RoaJ 154
Glenwood Springs, Colorado 8160 I
Phone: 970-945-7988
Fax: 970·945-8454
e ma il : h pgeo@hpgeotec h.com
Job No. 115 275A
Subject: Observation of Excavation, Proposed Residence, Lot 5, River Ridge Drive,
Garfield County, Colorado
Dear Mr. and Mrs. Douglas:
As requested, a representative of Hepworth-Pawlak Geotechnical, Inc. observed the
excavation at the subject site on September 19, 2015 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 July 15,
2015, Job No. 115 275A.
The proposed residence is essentially the same as described in our previous report.
Spread footings placed on the natural soils and sized for an allowable bearing pressure of
3,000 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 6V2 to 7 feet deep on the north end and up to 12 feet deep at the southeast corner.
The soils exposed in the bottom of the excavation consisted of slightly silty sandy gravel
and cobbles with small boulders. The excavation bottom was loose from the excavation
equipment. 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 on the site and suitable for support of spread footings designed for the
recommended allowable bearing pressure of 3,000 psf. Loose disturbed soils should be
smoothed out, heavily 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 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
Parker 303-841-7119 • Colorado Springs 719-633-5 562 • Silverthorne 970-468-1989
Dave and Judy Douglas
September 21, 2015
Page 2
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.
Steven L. Pawlak,
Rev . by: DEH
SLP/ksw
Job No. 115 275A