HomeMy WebLinkAboutObservation of Excavation 08.20.20181(4
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Geotechnlcal Engineering 1 Engineering Geology
Materials Testing 1 Environmental
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax: (970) 945-8454
Email: hpkglenwood@kumanisa.com
August 20, 2018
Brian Moriarty
P. O. Box 2416
Silverthorne, Colorado 80498
Briguy922@comcast.net
Office Locations: Parker, Glenwood Springs, and Silverthorne, Colorado
Project No. 17-7-876
Subject: Observation of Excavation, Lot 89, Filing 7, Elk Springs, 95 Gossamer Road,
Garfield County, Colorado
Dear Brian:
As requested, a representative of H-P/Kumar observed the excavation at the subject site on
August 20, 2018 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 January 16, 2018, Project No. 17-7-876.
At the time of our visit to the site, the foundation excavation had been cut in two levels from 1 to
7 feet below the adjacent ground surface with a 2 foot step between levels. The soils exposed in
the bottom of the excavation consisted of basalt cobbles and boulders in a sandy silt matrix. 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 2,000 psf. Loose disturbed soils in the footing areas should be 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 other biological contaminants
Brian Moriarty
August 20, 2018
Page 2
(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,
H -P -4 KU MAR
Robert L. Duran, E. I.
Reviewed by:
Steven L. Pawlak, P. E.
RLD/ksw
cc: D.M. Neuman Construction — Mike Gueriara (mike @ dfnneunian.com)
H-P%KUMAR
Project No. 17-7-876