HomeMy WebLinkAboutObservation of Excavation
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
April 23, 2025
RC Schneider Construction
Attn: Bob Schneider
218 East Valley Road
Carbondale, Colorado 81623
rcschneiderconst@gmail.com
Project No. 24-7-702.A
Subject: Observation of Excavation, Proposed Residence, Lot 46, Panorama Ranches,
46 Sunlight Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on April 16, 2025 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 February 12, 2025, Project No. 24-7-702.
The proposed residence has been designed to be supported by spread footings placed on 3 feet
of compacted structural of road base and sized for an allowable bearing pressure of 1,500 psf.
At the time of our visit to the site, the foundation excavation had been cut in one level from
about 5½ to 9 feet below the adjacent ground surface and 3 feet below design footing bearing
level. The soils exposed in the bottom of the excavation consisted of very stiff sandy silty clay
which had been compacted. No free water was encountered in the excavation and the soils were
slightly moist. Results of laboratory testing performed on a sample of road base taken from the
site are shown on Figures 1 and 1A.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and suitable for placement of compacted structural fill to support spread footings
designed for the recommended allowable bearing pressure of 1,500 psf. A sample of the road
base material stockpiled at the site was taken for laboratory Proctor compaction testing.
Compaction testing should be performed on a regular basis during the structural fill placement.
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
Tested By: KO Checked By: SLP
COMPACTION TEST REPORT
Dr
y
d
e
n
s
i
t
y
,
p
c
f
132.2
132.7
133.2
133.7
134.2
134.7
Water content, %
6 6.5 7 7.5 8 8.5 9
7.5%, 134.3 pcf
ZAV for
Sp.G. =
2.62
Test specification:ASTM D 698-12 Method C Standard
GW-GM A-1-a NV NP 0.0 8.4
Class 6 Aggregate Base Course
24-7-702.A RC Schneider Construction
See Figure 1A for classification results.
4/16/2025
1
Elev/Classification Nat.Sp.G.LL PI % >% <
Depth USCS AASHTO Moist.3/4 in.No.200
TEST RESULTS MATERIAL DESCRIPTION
Project No.Client:Remarks:
Project:
Date:
Location: On Site Stockpile Sample Number: 082-25
Kumar & Associates, Inc.
Glenwood Springs, Colorado Figure
Maximum dry density = 134.3 pcf
Optimum moisture = 7.5 %
46 Sunlight Drive, Lot 46, Panorama Ranches, Garfield County, Colorado
Tested By: KO Checked By: SLP
Kumar & Associates, Inc.
Glenwood Springs, Colorado
4/16/2025
1A
CDOT Class 6 Aggregate Base Course
PL=LL=PI=
D90=D85=D60=
D50=D30=D15=
D10=Cu=Cc=
USCS=AASHTO=
*
Class 6 Aggregate Base Course
1
.75
.375
#4
#8
#16
#30
#50
#100
#200
100.0
100.0
67.0
47.0
36.0
30.0
23.0
16.0
11.0
8.4
100
95-100
30-65
25-55
3-12
NP NV NP
14.2056 13.0867 7.7919
5.4115 1.1800 0.2665
0.1205 64.68 1.48
GW-GM A-1-a
See Figure 1 for standard Proctor compaction results.
RC Schneider Construction
46 Sunlight Drive, Lot 46, Panorama Ranches, Garfield County,
Colorado
24-7-702.A
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: On Site Stockpile
Sample Number: 082-25 Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.*PASS?
SIZE FINER PERCENT (X=NO)
PE
R
C
E
N
T
F
I
N
E
R
0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.0010.010.1110100
CDOT Class 6 Aggregate Base Course
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 53.0 12.7 14.9 11.0 8.4
6
i
n
.
3
i
n
.
2
i
n
.
1½ i
n
.
1
i
n
.
¾ i
n
.
½ i
n
.
3/
8
i
n
.
#4 #1
0
#2
0
#3
0
#4
0
#6
0
#1
0
0
#1
4
0
#2
0
0
Particle Size Distribution Report