HomeMy WebLinkAboutObservation of Excavation 10.26.20221(+AGeoteclmical 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 26, 2022
SCIB, LLC
Attn: Luke Gosda
0115 Boomerang Road, Suite 5201 B
Aspen, Colorado 81611
lake. og sda(d)sunriseco.com
Project No. 21-7-435
Subject: Observation of Excavation, Proposed Residence, Lot 39, Phase 3, Ironbridge,
Blue Heron Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on October 5 and 24, 2022 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 July 8, 2021, Project No. 21-7-435.
The residence is similar to that described in our previous report except that a basement level will
underlie the north part of the building. Spread footings placed on the existing site soils and sized
for an allowable bearing pressure of 1,500 psf were designed for the foundation support.
At the time of our initial visit to the site, the basement excavation had been cut in 2 levels from
about 2 to 5'/Z feet below the adjacent ground surface. The soils exposed in the bottom of the
excavation consisted of existing fill in the upper level and natural sandy silt and clay in the lower
level. The garage area footings are designed to bear on the existing grade and it was
recommended to scrape off the root zone and compact the subgrade prior to setting footing
forms. When observed on October 24, the footings for the building were constructed and
foundation walls had just been poured. No free water was encountered in the excavation and the
soils were slightly moist to 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. 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
SCIB, LLC
October 26, 2022
Page 2
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 & A
Steven L.PE
SLP/kac
Kumar & Associates, Inc. Project No. 21-7-435