HomeMy WebLinkAboutSubsoil Study for Foundation Design 03.04.2022lcltå.ffiimfm,:i';-*
Añ Em#oy.a O*ncd Comparry
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumarusa.com
Ofüce Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
March 4,2022
Todd Wilson
52089 Highway 6, Apt. B-311
Glenwood Springs, Colorado 81601
tawl3l3@gmail.com
Project No.22-7-149
Subject: Subsoil Study for Foundation Design, Proposed Residence, Lot 31, Filing 9,
Elk Springs Subdivision,2Sl2 Elk Springs Drive, Garfield County, Colorado
Dear Todd:
As requested, Kumar & Associates, Inc. performed a subsoil study for design of foundations at
the subject site. The study was conducted in accordance with our agreement for geotechnical
engineering services to you dated January 31,2022. The data obtained and our
recommendations based on the proposed construction and subsurface conditions encountered are
presented in this report.
Proposed Construction: The proposed residence has not been designed. We assume that it will
be one to two story over a crawlspace or slab-on-grade located on the site in the area of the pits
shown on Figure 1. Cut depths are expected to range between about 2 to 5 feet. Foundation
loadings for this type of construction are assumed to be relatively light and typical of the
proposed type of construction.
If building conditions or foundation loadings are significantly different from those described
above, we should be notified to re-evaluate the recommendations presented in this report.
Site Conditions: The site was vacant and slopes down to the south at about 5%oto 7%o grade.
The building envelope is vegetated with grass and weeds with sagebrush near Elk Springs Drive
on the west side of the lot.
Subsurface Conditions: The subsurface conditions at the site were evaluated by excavating
two exploratory pits at the approximate locations shown on Figure 1. The logs of the pits are
presented on Figure 2. The subsoils encountered, below about I foot of topsoil, consist of 1 to
2 feet of stiff, sandy silty clay overlying basalt gravel, cobbles and boulders in a white, clayey,
silty sand matrix. Results of a gradation analysis performed on a sample of the clayey, silty,
gravelly sand matrix soils (minus 5-inch fraction) obtained from the site are presented on
Figure 3. No free water was observed in the pits at the time of excavation and the soils were
slightly moist to moist.
R€CEryED
.?flfiñ,,r,.f.fi,*##Äl
5
s
¿
\
I
I
!I
1
,,
Itt
lr--I\ PrTt I
I\l
2 I
,t
I,t
LOT 31 l
\
\
\
\
I
I
I
I
LOT 30
0
APPROXIMATE SCALE-FEET
22-7 -1 49 Kumar & Associates LOCATION OF EXPLORATORY PITS Fig. 1
ín
I
r
s
PIT 1 PIT 2
0 0
t-IJ
t¡JtL
IIFo-
IJo
I +4=18-i -zoo=¿2
LL=38
Pl=10
t-L¡l
UJt!
I-t'-(L
lfjô
5 5
TOPSOIL; ORGANIC SANDY SILTY CLAY, FIRM, MOIST, DARK BROWN (3 TO 4 INCHES OF
FROSr).
CLAY (CL); SILTY, SANDY, STIFF, SLIGHTLY MOIST, BROWN.
BASALT ROCK FROM GRAVEL TO BOULDER SIZE (GM_SM); IN WHITISH SILTY SAND MATRIX,
DENSE, MOIST, DARK GRAY, BASALT ROCKS.
t DISTURBED BULK SAMPLE
I PRACTICAL AUGER REFUSAL.
NOTES
1. THE EXPLORATORY PITS WERE EXCAVATED WITH A BACKHOE ON FEBRUARY 15,2022.
2. THE LOCATIONS OF THE EXPLORÀTORY PITS WERE MEASURED APPROXIMATELY BY PACING FROM
FEATURES SHOWN ON THE SITE PLAN PROVIDED.
3. THE ELEVATIONS OF THE EXPLORATORY PITS WERE NOT MEASURED AND THE LOGS OF THE
EXPLORATORY PITS ARE PLOTTED TO DEPTH.
4. THE EXPLORATORY PIT LOCATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE
IMPLIED BY THE METHOD USED.
5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY PIT LOGS REPRESENT THE
APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL.
6. GROUNDWATER WAS NOT ENCOUNTERED IN THE PITS AT THE TIME OF EXCAVATION. PITS WERE
BACKFILLED SUBSEQUENT TO SAMPLING.
--v
Fig. 222-7 -1 49 Kumar & Associates LOGS OF EXPLORATORY PITS
ä
SIEVE ANALYSISHYOROMETER ANALYSIS
u.s. slaf,o^Ro 3ER|ES
¡,t HRS 7 HRS IMIN l2
IIIE RilDINêS
Áôvtñ raútN ¡MtN
'1'-r I
.....: ::.i....1.....i¡;t
I
..!...i.....;l
---- -¡----- ,vt^--
I
..........tt--^--^1--- ---'
-._._;...1...,..,....-.-_..,__..
-;]-
I :--ii
rl-
...... I I -
tl- --r -f--r l-
I . t...... .
........¡-l--.- *r"l-.
a
E
roo
90
80
70
60
50
40
30
20
t0
o
o
lo
20
t0
10
50
60
70
ao
go
roo
I
Ê
H
,123 2.OOF PARTICLES IN MILLIMETERS
CLAY TO SILT COEBLES
GRAVEL 18 % SAND 40 %
LIQUID LIMIT 38 PLASTICITY INDEX
SAMPLE OF: Cloyey Sllty Grovelly Sond Mdlrlx Sôlls
SILT AND CLAY
to
12%
FROM:PlT2ø3-1'
lh.!ô l.tl rcsull! épply only lo lh.
sompl€s whlch wcra losl€d. ThrLlllñg ¡rporl tholl not bs r.produc.d,
.xôcpl ln lull, sllhoul lhc arlll€n
opprcvql gf Kumdr * Arsoc¡olcÊ, lnc.
Sl.v. onoly3h l.ll¡ng l. p.rlormod lnqccordcnc. w¡lh ASTM D6913, ASTM 07928,
ASTM Cl36 ondlor ASTM Dll,l0.
SAND GRAVEL
FINE MEOIUM COARSE FINE COARSE
22-7 -1 49 Kumar & Associates GRADATION TEST RESULTS Fis. 3