HomeMy WebLinkAboutSoils Report for Foundation & Septic Design 07.21.2016H-PKUMAR
Geotechnical Engineering 1 Engineering Geology
Materials Testing 1 Environmental
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax: (970) 945-8454
Email: hpkglenwood@kumarusa.com
July 21, 2016
Cuc Construction
Attn: Ernesto Cuc
635 Glassier Drive
Carbondale, Colorado 81623
(gm.ernesto @ hotmail.com)
Office Locations: Parker, Glenwood Springs, and Silverthorne, Colorado
Project No.16-7-199
Subject: Subsoil Study for Foundation Design, Proposed Metal Building, Lot 2, Coke
Ovens Expansion, County Road 163 (Airport Road), Glenwood Springs, Colorado
Dear Mr. Cuc:
As requested, H-P/Kumar 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 Cuc Construction dated July 11, 2016. The data obtained and our recommendations
based on the proposed construction and subsurface conditions encountered are presented in this
report.
Proposed Construction: Development plans were preliminary at the time of our study. The
proposed metal building will be 40 feet by 60 feet with slab -on -grade floor. The building will be
located in the area of the exploratory pits shown on Figure 1. Cut depths are expected to range
between about 3 to 6 feet. Foundation loadings for this type of construction are assumed to be
relatively light to moderate and typical of the proposed type of construction. A retaining wall
will be constructed uphill of the building into the hillside.
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 property is vacant of structures with the exception of some coke oven
ruins. Vegetation consists of sage brush, grass and weeds on the hillside with sparse grass and
weeds in the building area. The ground surface has been disturbed and graded relatively flat. A
two -track dirt road previously crossed the middle of the property from south to north. The
hillside above the property is northeast facing and steeply sloping down into the building area.
The building area is relatively flat with a slight slope down to northeast. Numerous cobbles and
boulders are visible on the hillside.
Subsurface Conditions: The subsurface conditions at the site were evaluated by excavating
four exploratory pits at the approximate locations shown on Figure 1. The Logs of the pits are
-2 -
presented on Figure 2. The subsoils encountered, below up to about 5 feet of man -placed fill,
generally consist of sandy gravel and cobbles with small boulders. Topsoil and silty sandy
gravel fill was encountered in Pit 1 overlying the natural sandy gravel and cobble soils. Results
of gradation analyses performed on samples of the sandy gravel and the fill material (minus 5
inch fraction) obtained from the site are presented on Figure 4. No free water was observed in
the pits at the time of excavation and the soils were slightly moist.
Foundation Bearing Conditions: The natural granular soils are adequate for support of spread
footing foundations. Man -placed fill approximately 5 feet in depth was encountered in the
exploratory pits and extends across most of the building area. The fill material should be
completely removed from beneath the building area and the excavation extended down to the
natural soils. Structural fill such as road base or suitable processed onsite soils should be used to
return the grade to design bearing levels. Structural fill placed below footing bearing level
should be compacted to at least 9$ percent standard Proctor density at a moisture content near
optimum and extend an equal distance laterally as deep below bearing level.
Foundation Recommendations: Considering the subsoil conditions encountered in the
exploratory pits and the nature of the proposed construction, we recommend spread footings
placed on the undisturbed natural soil or compacted structural fill designed for an allowable soil
bearing pressure of 3,000 psf for support of the proposed metal building. The bearing soils
should have low compressibility potential and low post -construction foundation settlement.
Footings should be a minimum width of 16 inches for continuous walls and 2 feet for columns.
The existing fill and loose disturbed soils within the excavation should be removed or moistened
and compacted. Exterior footings should be provided with adequate cover above their bearing
elevations for frost protection. Placement of footings at least 36 inches below the exterior grade
is typically used in this area. Continuous foundation walls should be reinforced top and bottom
to span local anomalies such as by assuming an unsupported length of at least 10 feet.
Foundation walls acting as retaining structures should also be designed to resist a lateral earth
pressure based on an equivalent fluid unit weight of at least 45 pcf for the on-site granular soil as
backfill. A representative of the geotechnical engineer should observe all footing excavations
and test structural fill for compaction prior to concrete placement to evaluate bearing conditions.
A sliding coefficient of 0.50 and equivalent fluid unit weight of 450 pcf can be used to resist
lateral loads on retaining walls.
Floor Slabs: The natural on-site soils, exclusive of topsoil, are suitable to support lightly to
moderately loaded slab -on -grade construction. The existing fill material should be removed
from beneath floor slab areas. To reduce the effects of some differential movement, floor slabs
should be separated from all bearing walls and columns with expansion joints which allow
unrestrained vertical movement. Floor slab control joints should be used to reduce damage due
to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be
established by the designer based on experience and the intended slab use. A minimum 4 inch
layer of relatively well graded sand and gravel such as road base should be placed beneath
interior slabs for support. This material should consist of minus 2 inch aggregate with less than
50% passing the No. 4 sieve and less than 12% passing the No. 200 sieve.
-3 -
All fill materials for support of floor slabs should be compacted to at least 95% of maximum
standard Proctor density at a moisture content near optimum. Required fill can consist of the on-
site granular soils devoid of vegetation, topsoil and oversized rock. The existing fill material
containing debris and may not be suitable for slab support.
Underdrain System: Although free water was not encountered during our exploration, it has
been our experience in the area that local perched groundwater can develop during times of
heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a perched
condition. We recommend below -grade construction, such as retaining walls be protected from
wetting and hydrostatic pressure buildup by an underdrain system.
The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above
the invert level with free -draining granular material. The drain should be placed at each level of
excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1% to
a suitable gravity outlet. Free -draining granular material used in the underdrain system should
contain less than 2% passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a
maximum size of 2 inches. The drain gravel backfill should be at least 11/2 feet deep.
Surface Drainage: The following drainage precautions should be observed during construction
and maintained at all times after the metal building has been completed:
1) Inundation of the foundation excavations and underslab areas should be avoided
during construction.
2) Exterior backfill should be adjusted to near optimum moisture and compacted to
at least 95% of the maximum standard Proctor density in pavement and slab areas
and to at least 90% of the maximum standard Proctor density in landscape areas.
Free -draining wall backfill should be capped with about 2 feet of the on-site, finer
graded soils to reduce surface water infiltration.
3) The ground surface surrounding the exterior of the building should be sloped to
drain away from the foundation in all directions. We recommend a minimum
slope of 6 inches in the first 10 feet in unpaved areas and a minimum slope of 3
inches in the first 10 feet in pavement and walkway areas. The uphill retaining
wall should direct surface runoff around the building.
4) Roof downspouts and drains should discharge well beyond the limits of all
backfill.
Limitations: This study has been conducted in accordance with generally accepted geotechnical
engineering principles and practices in this area at this time. We make no warranty either
express or implied. The conclusions and recommendations submitted in this report are based
upon the data obtained from the exploratory pits excavated at the locations indicated on Figure 1
and to the depths shown on Figure 2, the proposed type of construction, and our experience in
the area. 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. Our
findings include interpolation and extrapolation of the subsurface conditions identified at the
exploratory pits and variations in the subsurface conditions may not become evident until
excavation is performed. If conditions encountered during construction appear different from
-4 -
those described in this report, we should be notified at once so re-evaluation of the
recommendations may be made.
This report has been prepared for the exclusive use by our client for design purposes. We are not
responsible for technical interpretations by others of our information. As the project evolves, we
should provide continued consultation and field services during construction to review and
monitor the implementation of our recommendations, and to verify that the recommendations
have been appropriately interpreted. Significant design changes may require additional analysis
or modifications to the recommendations presented herein. We recommend on-site observation
of excavations and foundation bearing strata and testing of structural fill by a representative of
the geotechnical engineer.
If you have any questions or if we may be of further assistance, please let us know.
Respectfully Submitted,
H -P 4- KU AR
Louis Eller
Reviewed by:
Steven L. Pawlak, P.E : *I 1 62 22 1 ](
LEE/ksw owl `Wr"9
;441...* cp,
attachments Figure 1 — Lo :_ •loratory Pits
Figure 2 — Logs of Exploratory Pits
Figure 3 — Legend and Notes
Figure 4 — Gradation Test Results
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PROPERTY I+OU',DAR7
l
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r r•APr•Pr—�
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50 0 50 100
APPROXIMATE SCALE -FEET
17'43.31
3075.36
•• 663.43
C - 881,63
CE S 3316'S8'E
17'43 .l •� �.,
R 303 v.
L � 849.72
C • 64..30
C1 - P44 32•36 3d' W `.� 5E7 X 50 Tl1ANGULAA
h1GSESS iCESS
ACCESS EASEPAENt
WATER vALVE (MP
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DUET X
STAND !r! (TY?
'E\ loo R W
16-7-199
H-P-KUMAR
rair G I (^SLerrr t4Pgl'
1Ri[r.1Ni r ttrormQt•
LOGS OF EXPLORATORY PITS
Figure 1
Depth - Feet
LLC
0
•
•
0
5
10
PIT 1 PIT 2
-1+4=67
-200=3
\ f
PIT 3
PIT 4
Note:
Explanation of symbols
presented on Figure 3.
0
5
10
16-7-199
H-P==
LOGS OF EXPLORATORY PITS
Figure 2
LEGEND:
CI •
e
NOTES:
Topsoil; organic sandy silt and clay, firm, slightly moist, dark brown.
Gravel (gm); sandy, silty, cobbles, dense, slightly moist, red, rounded rock.
Gravel, cobbles and boulders (gm-gp); slightly silty, sandy, dense, slightly moist,
reddish brown, rounded rock.
Fill; silty sandy gravel with cobbles, loose to medium dense, slightly moist,
mixed dark brown, reddish brown and gray, contains coal ash and bricks.
Disturbed bulk sample.
1, Exploratory pits were excavated on July 13, 2016 with a trackhoe.
2, Locations of exploratory pits we,e measured approximately by pacing from the client
designated building area,
3. Elevations of exploratory pits were not measured and the logs of exploratory pits are
drawn 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 transitions may be gradual.
6. No free water was encountered in the pits at the time of excavating. Fluctuation in
water level may occur with time.
7. Laboratory Testing Results:
+4 = Percent retained on the No, 4 sieve
-200 = Percent passing No. 200 sieve
16-7-199
H-P�KUMAR
LEGEND AND NOTES
Figure 3
100
10
ao
70
40
SO
40
10
70
10
KYapoki TER ANALYSTS
1 a ±11
•
001 .0�7
100
70
30
0
.7-02 .900
S'EVE ANALYSIS
111
.0111 .077 Ars .1• • A
171 AN1.1■ 7? 31, a 77 07 14 1.1 707 177
DIAMETER OF PARTICLES IN MILLIMETERS
157
10
20
70
1D
30
40
70
S0
00
100
00
CLAY TO SILT
SAND
GRAVEL
FINE I MEDIUM ]COARSE
FINE 1 COARSE
COBBLES
GRAVEL 67 X
LIQUID LIMIT
SAMPLE OF: Sandy Grays! with Cobbles
SAND
NYDROI.a CT[R ANALYSIS
14 717 7 IMS
1'oC 0C40*.0
31 %
PLASTICITY INDEX
SILT AND CLAY 3 X
FROM: PR 1 0 5'-5'
SIEVE ANALYSIS
Y.5. 7rAu0440 1101[7 Gx.a SOYAIL 01.70,001
n 1 Lar.. 4477 Iwl. 1100 H0 440 470 al■ 1,10 41 94 ./.' 71.E r 1/2'
.401 0011
L
l0
10
20
7s
40
AO
AO
70
00
110
f 1 1 111 1 1 _1 1 1 111 I 1 7 1 1 1 111 100
Orf A77 ,070 .16a .290 ..00 1.10 7 74 . 7 . 5 to 70.1 7A7 177 700
DIAMETER OF PARTICLES IN MILLIMETERS 102
CLAY TO SILT
SAND
GRAVEL
GRAVEL 75 X
UOUID LIMIT
FINE I MEDIUM [COARSE FINE I COARSE
SAND 20 X
PLASTICITY INDEX
SAMPLE OF: Slightly Silly Sandy Gravel FROM: PII 3 0 2' — 3'
with Cabbies (FBI)
SILT ANO CLAY 5 %
I11s.1 1411 04101 VOW/ Q.Ir l0 SS..
.Ompl.s .hkh oars 111r.d. Ths
r.1Hnq ?.pail oho? n01 pa 010redO040.
140041 (1 000. 1.)101441 1114 .111114
approve'? of OYmor ■ A..elloh.. ln..
Sl.'. *noires 1.1010 h perfeenl.d 111
.,Condom. +0101 A5111 0127, AS7U C135
end/or ASTu 01110.
COBBLES
16-7-199
H-P-KUMAR
r. 7o,Ktiti,_ I Ev).1Ir..rr41 I LA 41,7(11.;71 7 )117
1.1:1:11,7171.:7.11 iiuu:r.^.vnt.11
LOGS OF EXPLORATORY PITS
Figure 4
PERC HOLE 1
N:
E: 80954.3297
PROPOSED OUILp1NO .....
ROAD}
PARC HCL "�-
N:49508.2678
E: 80964.8569 -�
p,Cpos8b
aRIVE wAr
PRO DbE10'--ADH FIELD
Iftr
PROPOSED DRIVE WA �..�
•
• x
X
15 0
15 "
pppRoyaggE SCALE-fEET
14 lam*!er r
16-7-1999.031.101air u' Env re"rui
s,.
3374
LOGS OF EXPLORATORY PITS
Figure 1
0_
m
S
`1 +4:53
- -1 -200=13
PROFILE PIT 2
0
5
10
Note-
Explanation of symbols
presented on Figure 3-
a
A
1
a
LEGEND:
6.
NOTES:
Fill: silty sandy gravel with cobbles. loose to medium dense, slightly moist,
mixed dark brown. reddish brown and gray, contains coal ash and bricks.
Gravel (GM -GP); sandy, slightly lo silty. ccbbles, dense, slightly moist, brown, rounded rock,
Disturbed bulk sample.
1. Exploratory pits were excavated on October 3. 2016 with a trackhoe.
2. The exploratory pits were located by the client.
3. Elevations of exploratcry pits were not measured and the logs of exploratory pits are
drawn 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 transitions may be gradual.
6. No free water was encountered in the pits at the time of excavating. Fluctuation in
water level may occur with time.
7. Laboratory Testing Results:
.l-4 G Percent retained on the No. 4 sieve
-200 Percent passing No. 200 sieve
t0
50
70
w
OD
410
70
20
10
GRAVEL S3 %
LIQUID LIMIT
SAMPLE OF: Silty Sandy Grovel with Cabbies
SAND
34
PLASTICITY INDEX
SILT ANC CLAY 13 %
FROM: Profit* Pit t 0 7.-0.
0
10
20
70
10
0
00
1h•tr 1.11 1rlolt1 92511
.dtr i Ih•
f0np1 1 ..434„t...R 4391 e{ 4961094csd•
ltafln0 . pII1 h0R10u1 1t*. ..151an
01121101 In Sf s1. '. 1t70Ci &d1. Ise
0112140191 s 04 KY1,.1 A r 10:.57. in
W4...4 ar.11fst011h 1►37 19072. 7.5{!1 (5 36
eceaN 61.4' � ..
LOGS OF EXPLORATORY PITS
HYO FDLUCTC5 ANALYSIS
SfCYE ANALYSIS
14 Mal
13 WA
run .L4.O+1rr3
t 11113
41 WI. 50501 111.144 .1+4?,
411.+1
1150
1.00
Lt l
1.5. 0740Aa7 5(01(3
170 1.0 #10 0(1 I10J9
1 1 LA] 1 L r
01
• 1
1/5'
LLIL
0.045 50019,1 4308.1117
0/a- 1 I/ ' s. -r- j
I
4 1 1 I! l 1 1
L 1
1 1 f 1 1
f i
t It
I
01
.303
.005 .095 .015
.937
.0
DIAIIETTR
5 .100 .000 .150 1 t0 7.3{ 1, 7
OC PARTICLES iM MILLIMETERS
9.5
10 361 79.7 171 1.0
107 I.
CLAY TO SILT
SAND
GRAVEL
COBBLES
FIN( I MEDIUM !COARSE
FINE
J COARSE
GRAVEL S3 %
LIQUID LIMIT
SAMPLE OF: Silty Sandy Grovel with Cabbies
SAND
34
PLASTICITY INDEX
SILT ANC CLAY 13 %
FROM: Profit* Pit t 0 7.-0.
0
10
20
70
10
0
00
1h•tr 1.11 1rlolt1 92511
.dtr i Ih•
f0np1 1 ..434„t...R 4391 e{ 4961094csd•
ltafln0 . pII1 h0R10u1 1t*. ..151an
01121101 In Sf s1. '. 1t70Ci &d1. Ise
0112140191 s 04 KY1,.1 A r 10:.57. in
W4...4 ar.11fst011h 1►37 19072. 7.5{!1 (5 36
eceaN 61.4' � ..
LOGS OF EXPLORATORY PITS