HomeMy WebLinkAboutObservation of Excavation 10.25.23+� Kur�r ni Associates, Mc.®
'� Geotechnical and Materials Engineers 5020 County Road 154
and Environmental Scientists Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
An Employee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
October 25, 2023
James Gornick Building Specialists
Attn: Jim Gornick
1005 Cooper Avenue
Glenwood Springs, Colorado 81601
i gomick 1988(&gmail.com
Project No. 23-7-407
Subject: Observation of Excavation, Proposed Residence, Lot 1, River Ridge, River Ridge
Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on October 24, 2023 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 4, 2023, Project No. 23-7-407.
The residence foundation was designed to be supported by spread footings sized for an allowable
bearing pressure of 2,500 psf. The living area will have a structural floor above crawlspace with
a slab -on -grade garage floor.
At the time of our visit to the site, the foundation excavation had been cut in 2 levels from 2 to
6 feet below the adjacent ground surface. The garage was a perimeter trench excavation about
2 feet higher than the main level excavation grade. The soils exposed in the bottom of the
excavation consisted of silty sandy gravel with cobbles which had been compacted. No free
water was encountered in the excavation and the soils were slightly moist to moist.
The gravel soils 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 2,500 psf. Loosened disturbed soils in the footing areas should be moistened
and compacted or removed 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 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.
James Gornick Building Specialists
October 25, 2023
Page 2
If you have any questions or need further assistance, please call our office.
Sincerely,
Kumar & Associates,
:n 15
Steven L. Pawlak, E-
SLP/kacO,n'•.,
Kumar & Associates, Inc. ` Project No. 23-7-407