HomeMy WebLinkAboutExcavation Observation 05.08.24Kumar & Associates, Inc.
'( 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.kumarasa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
May 8, 2024
Richard Kozial
2102 Grand Avenue
Glenwood Springs, Colorado 81601
richykoziolg, Qrnail. cam
Project No. 23-7-259
Subject: Observation of Excavation, Proposed Residence, Lot 30, Four Mile Ranch, 143
Maroon Drive, Glenwood Springs, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 1, 2024 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 20, 2023, Project No. 23-7-259.
We understand the proposed residence has been designed to be founded on spread footings
bearing on the natural granular soils and sized for an allowable bearing pressure of 2,000 psf.
At the time of our visit to the site, the foundation excavation had been cut in 4 levels from 4 to
13 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of relatively dense silty clayey sand in most areas with a minor depth of very sandy
clay in the garage area. Results of swell -consolidation testing performed on a sample of the
sandy clay taken from the garage area, shown on Figure 1, indicate the soils are not expansive
and exhibit a low hydrocompression potential under conditions of loading and wetting. 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 2,000 psf. Loose and disturbed soils and any mud should be removed in the
Richard Kozial
May 8, 2024
Page 2
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 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, Inc.
57322 - i
Robert L. Duran, P.E. IGW
RLD/
Attachment Figure 1 — Swell — Consolidation Test Results
cc: Lukasz Lowisz (lukaszlls@outlook.com)
Kumar & Associates, Inc. 0 Project No. 23-7-259
SAMPLE OF: Silty Sandy Clay
FROM: Garage Footer Depth
WC = 14.0 DD = 97 pcf
� ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
DUE TO WETTING
Theee test roeuMs eppry onH to the
eamples tested. The tesbn. roDort
.Hell not M nproduced, xcsDt in
lull, wiNoul ihs wrttlen approval of
Kumar aM /wociatu, Inc. Swell
Domdidotion testing pertormed in
accordance with ASfM D—L548.
—
�
1
0
J —1
J
Li
N
—2
Z
O
F-
a
J
—3
O
N
Z
O
—4
—5
—6
—7
v
i
N 1 1.0 APPLIED PRESSURE - KSF 10 100
r,
f
a
E
G
i
Eb
�j
n E
23-7-259 Kumar & Associates SWELL —CONSOLIDATION TEST RESULTS
Fig. 1