HomeMy WebLinkAboutObservation of Excavation 10.22.2019Kumar & Assoclatas, lac.
Geotechnical and Materials Engineers
end Environmental Scientists
An Employee Owned Company
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
October 22, 2019
Matt Jurmu
2906 Hager Lane
Glenwood Springs, Colorado 81601
m att(a)j ancki laconstructi on. cam
Subject:
Gentlemen:
Project No. 19-7-349
Observation of Excavation, Proposed Residence, Lot 37, Spring Ridge Reserve,
Hidden Valley Drive, Garfield County, Colorado
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on October 21, 2019 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 June 24, 2019, Project No. 19-7-349.
The proposed residence construction is essentially the same as presented in our previous report
except the garage was moved to the downhill side of the residence rather than the uphill side.
Spread footings placed on the natural clay soils and sized for an allowable bearing pressure of
1,500 psf were designed for the foundations support.
At the time of our visit to the site, the foundation excavation had been cut in two levels generally
from 1 to 81/2 feet below the adjacent ground surface. The soils exposed in the bottom of the
excavation mainly consisted of silty sandy clay except for topsoil in the garage footing trench
excavation. The topsoil was being removed and an email we received on October 22, 2019
showed the natural clay soils in the garage trench excavation had been removed. 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 1,500 psf. Loose 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 previous
report which are applicable should also be observed.
Matt Juriu
October 22, 2019
Page 2
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,
Kumar & Associates, to
Steven L. Pawlak
SLP/kac
Kumar & Associates, Inc. 9 Project No. 19-7-349