HomeMy WebLinkAboutObservation of Excavation 02.28.2023K+AGeotedmicai 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 Emptoyee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
February 28, 2023
SCIB, LLC
Attn: Luke Gosda
0115 Boomerang Road, Suite 5201B
Aspen, Colorado 81611
luke. og sda(i�sunriseco.com
Project No. 21-7-514.A
Subject: Observation of Excavation, Proposed Residence, Lot 263, Ironbridge, 59 River
Vista, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on February 27, 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 July 9, 2021, Project No. 21-7-514.
At the time of our visit to the site, perimeter and interior foundation trench had been cut in
mainly one level about 1 to 11/z feet below the adjacent ground surface. The soils exposed in the
bottom of the excavation and interior slab area consisted of previously placed structural fill
composed of medium dense, mixed sand, gravel and silt. The fill appeared to have been
compacted. No free water was encountered in the excavation and the soils were slightly moist to
moist and not frozen. Three in -place tests taken in the bottom of the trenches showed dry
density/moisture content of 116.3 pcf at 10.7%, 118.5 pcf at 8.2% and 122.1 pcf at 7.8% which
appear to be around 98% compaction.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and suitable for support of a heavily reinforced slab designed for the recommended
allowable bearing pressure of 1,500 psf. Loose disturbed soils should be compacted prior to
placing the radon barrier or concrete. 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.
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.
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
SCIB, LLC
February 28, 2023
Page 2
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,
o 15222
Steven L. Pawlak, P.E. :.� s /
SLP/kac
Kumar & Associates, Inc.' Project No. 21.7-514.A