HomeMy WebLinkAboutObservation of Excavation 09.05.18-A R
Geotechnlcal Engineering I Engineering Geology
Materia ls Testing I Environmental
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax: (970) 945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, Summit County, Colorado
September 5, 2018
Rob Classen
P.O. Box 1227
Glenwood Springs, Colorado 81602
(drawbd@rof.net)
Subject:
Project No. 16-7-473
Observation of Excavation, Proposed Residence, Lot 2, Filing 1, Elk Springs, Elk
Springs Drive, Garfield County, Colorado
Dear Mr. Classen:
As requested, a representative of H-P/Kumar observed the excavation at the subject site on
September 4, 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 October 13, 2016, Project No. 16-7-473.
At the time of our visit to the site, the foundation excavation was mostly complete and had been
cut in 4 levels from 2 to 6 feet below the adjacent ground surface. The soils exposed in the
bottom of the excavation mainly consisted of basalt gravel, cobbles and boulders in a sandy silt
matrix. In the upper, shallower cut area was a small amount of topsoil. No free water was
encountered in the excavation and the soils were dry to 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 1,500 psf. Loose disturbed soils in the footing areas should be removed and
the exposed soils moistened and compacted. Other recommendations presented in our previous
report which are applicable, such as stripping out the topsoil and protecting the bearing soils
from wetting after construction, 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.
Rob Classen
September 5, 2018
Page2
If you have any questions or need further assistance, please call our office.
Sincerely,
H -P~KUMAR
!fay ~
James H. Parsons, E.1
Reviewed by:
JHP/kac
cc: erian ( da ybrcakco nst @botmail.com)
H~KUMAR Project No. 16-7-473