HomeMy WebLinkAboutObservation of Excavation 01.15.18H.PVKUMAR
Geotechnical Engineering I Engineering Geology
Malerials Tesüng I Environmental
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax (970) 94s-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Gollins, Glenwood Springs, Summit County, Colorado
Jordan Architecture
Attn: Brad Jordan
P.O. Box 1031
Glenwood Springs, CO 81602
bradj ordanarchitect @ gmail.com
Project No. 17-7-259
Subject:observation of Excavation, Proposed Palmer Residence, 132 Red Cliff circle,
Lot26, Four Mile Ranch, Garfield County, Colorado
Dear Brad:
As requested, a representative of H-P/Kumar observed the excavation at the subject site on
January 11ü and l2ú',2018,to evaluate the soils exposed for foundation suppon 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 presenied our
findings in a report dated April 20,2017, Project No. 17-7-259.
At the time of our visit to the site, the foundation excavation for the residence and garage had
been cut in 2 levels from about 3 to I feet below the adjacent ground surface. The soils exposed
in the bottom of the excavation consisted of sandy clay and silt, and silty sand with gravel.
Boulders up to about 5 feet in diameter had been removed from the excavation, and boulders up
to about 3 feet in diameter were observed in the walls of the excavation. The base of the
excavation was probed with a metal hand probe, with penetrations of about 2to 6 inches. 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 1500 pounds per square foot (psf¡. Loose and disturbed soils should be
removed in the footing areas to expose the undisturbed natural soils. Voids created by boulder
removal should be backfilled with properly compacted structural fill or lean-mix concrete. 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 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
Jordan Architecture
January 15,2018
Prge2
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,
H.P+KUMAR
James A. Parker, P.E., P.G
Rev.by: SLP
JAP/lssw
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Project No. 17-7.259