HomeMy WebLinkAboutObservation of Excavation 05.30.2018H-P�XUMAR
Geotechnical Engineering I Engineering Geology
Materials 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
May 30, 2018
Chris Erickson
P.O. Box 3782
Basalt, Colorado 81621
chriscricksonwl@gmail.com
Project No. 17-7-567
Subject: Observation of Excavation, Proposed Residence, Lot 13, Cottonwood Hollow,
5000 Cattle Creek Road, Garfield County, Colorado
Gentlemen:
As requested, a representative of H-P/Kumar observed the excavation at the subject site on May
25, 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 August 10, 2017, Project No. 17-7-567.
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 2,000 psf were
designed for the foundation support based on our previous study.
At the time of our visit to the site, the foundation excavation had been cut in one level from 3 to
5 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of basalt gravel, cobbles and boulders in a sandy silt and clay matrix. The downhill,
southern part appeared to have penetrated the previously placed fill soils. 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 should be removed in the footing areas to
expose the undisturbed natural 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 limited subsurface exploration at the site.
Chris Erickson
May 31, 2018
Page 2
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 :,'- KU MAR
Steven L. Paw
SLP/kac
n-rqsr%uiv~
Project No. 17-7-567