HomeMy WebLinkAboutObservation of Excavation 10.20.17H.PVKUMAR
Geotechnical Engineering I Engineering Geology
Materials Testing I Envircnmentral
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax (970) 945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Parker, Glenwood Springs, and Summit County, Colorado
October 20,20t7
Kirstie F. Steiner
c/o Hayes Construction
Attn: Doug Hayes
1002 Blake Avenue
Glenwood Springs, Colorado 81601
dhayesconstruction @ gmail.com
Project No. l7-7-555
Subject:Observation of Excavation, Proposed Residence, Orchard Creek Ranch, 150
Canyon Creek Road, Garfield County, Colorado
Dear Ms. Steiner:
As requested, a representative of H-P/Kuma¡ observed the excavation at the subject site on
October 5 and 1I,2OIl 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 August9,2Ol7, Project No. 17-7-555.
At the time of our initial visit to the site, the main part of the foundation excavation was neariy
complete except for a soft clay area on the north side of the 2-car garage and the southeast corner
of the house which had not been excavated. We recommended that the soft clay be sub-
excavated about 1 foot
the footing grade in the
and 3-inch minus gravel be placed and compacted to stabilize
the house.
We returned to the site on October 1lth and observed that the excavation was complete. The
house excavation had been cut in multiple levels fromVz to 12 feet below the adjacent ground
surface. The soils exposed in the bottom of the excavation consisted of mostly stiff to very stiff
sandy silty clay. On the north side of the basement area adjacent to the 3-car garage, the
subgrade consisted of relatively dense silty sandy gravel with cobbles. The soft clay on the north
side ofthe Z-car garage had been sub-excavated and 3-inch minus sand and gravel had been
Kirstie F. Steiner
October 20,2017
Page2
placed which appeared to be stable and suitable for footing construction. No free water was
encountered in the excavation and the soils were slightly moist to noist.
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 1,500 psf. Loose and disturbed soils should be removed in the footing areas
to expose the undisturbed natural soils. The bearing soils should be protected from frost and
concrete should not be placed on frozen soils. Other recommendations presented in our previons
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
(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
ì"t TJ
i:
Daniel E. Hardin, P
Rev by: SLP
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H.PÈKUMAR
Project No. 17-7-555