HomeMy WebLinkAboutGeotechnial Investigation for Foundation Design 05.19.2020Grand Valley Consulting, LLC dba
141111 GEOTECHNICAL
GEOTECHNICAL INVESTIGATION AND FOUNDATION DESIGN
TWO PREFABRICATED OFFICES
25028 Highway 6&24
RIFLE, COLORADO
Prepared For:
Moody Construction & Sons, Inc.
Shawn Moddy
970-986-7244
shawn.moody@moodyandsons.com
Job No. 4,411
May 19, 2020
(970) 261-3415 • jwithers@geotechnicalgroup.net
3510 Ponderosa Way, Grand Junction, Colorado 81506
GEOTECHNICAL
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TABLE OF CONTENTS
SCOPE 1
SUMMARY OF CONCLUSIONS 2
SITE CONDITIONS 2
PROPOSED CONSTRUCTION 3
SUBSURFACE CONDITIONS 4
FOUNDATION RECOMMENDATIONS 5
SPREAD FOOTING FOUNDATION 5
FLOOR SYSTEMS RECOMMENDATIONS 6
BELOW -GRADE CONSTRUCTION 7
FOUNDATION DESIGN 7
BALLAST DESIGN 7
CONCRETE 7
SURFACE DRAINAGE 8
CONSTRUCTION MONITORING 9
LIMITATIONS 10
APPENDIX A — FIELD EXPLORATION
FIG. A-1 - Vicinity Map
FIG. A-2 — Location of Exploratory Test Pits
FIGS. A-3 to A-4 — Test Pit Logs
APPENDIX B — LABORATORY TESTING
FIG. B-1 — Laboratory Testing
FIG. B-2 to B-4 — Sieve Analysis Test Results
FIG. B-5 — Compaction Test Report
TABLE B -I — Summary of Test Results, 2 pages
1411 GEOTECHNICAL
[ ENciNEEPNE: aRDuP
APPENDIX C — DESIGN DETAILS
FIG. C-1 — Foundation Plan
FIG. C-2 — Foundation Notes
FIG. C-3 — Tank Ballast Plan
APPENDIX D SUPPORTING DOCUMENTS
FIG. D-1 — General Notes
FIG. D-2 — Unified Soil Classification System
FIG. D-3 — General Notes — Rock Properties
\I' GEOTECHNICAL
1 '.11 INEEf:INf�' L�I'?C1LIP
SCOPE
This report presents the results of a geotechnical investigation and foundation
design for two proposed offices to be located at 25028 Highway 6&24 in Rifle, Colorado.
Our investigation was conducted to explore subsurface conditions and provide foundation
recommendations and design for the proposed structures. The report includes
descriptions of subsoil and groundwater conditions found in two exploratory pits,
recommended foundation systems, allowable design soil pressures, and design and
construction criteria for details influenced by the subsurface conditions. This investigation
was performed in general conformance with our proposal No. 20-0568 dated April 14,
2020. This investigation used test pits, made by others, as opposed to exploratory borings
in order to reduce cost and time. Care should be taken to avoid locations of proposed
and future structures with the test pits and to place backfill in a well compacted manner,
as detailed in the "FOUNDATION RECOMMENDATIONS" section of this report.
The report was prepared from data developed during our field exploration,
laboratory testing, engineering analysis and experience with similar conditions. A brief
summary of our conclusions and recommendations follows. Detailed criteria are
presented within the report.
25028 Hwy 6&24: 5-19-20
Rifle, Colorado
GEG Job No. 4,411
GEOTECHNICAL
NLIN [;i: 1_1p
SUMMARY OF CONCLUSIONS
1. Subsurface conditions encountered in two test pits consisted of 4 to 6 feet
of clayey, gravelly sand variable fill with cobbles underlain by silty, sandy
clay variable fill with cobbles to the maximum depth of 10 feet below ground
surface. Groundwater was encountered in TP -2 at 8 feet below ground
surface.
2. Construction should not bear on locations of the test pits noted on Fig. 2.
Former test pits should be backfilled as described in the "RESIDENCE
FOUNDATIONS" section of the report.
3. Recommendations and design for foundations placed on well compacted
structural fill are presented herein. A discussion, including detailed design
and construction criteria are included in the text of the report.
4. We believe slab -on -grade construction supported by the soils encountered
will have potential for movement. Office areas with a level of finish should
be supported (as proposed) by structurally supported floors. Additional
discussion, including design and construction criteria, is included in the text
of the report.
5. Surface drainage should be designed for rapid runoff of surface water away
from the proposed structures in all directions. It is important to control water
sources and provide proper drainage as these are common causes of
distress.
SITE CONDITIONS
The subject site was located at 25028 Highway 6&24 in Rifle, Colorado. A vicinity
map showing the site location is included as Fig. A-1. The subject site is located within
the existing Central Aggregates parcel. Previously the area of the site was part of a gravel
pit excavation. The site is barren. The subject site was nearly flat and level. The site was
25020 Hwy 6024: 5-19-20
Rifle, Colorado
GEG Job No. 4,411
GEOTECHNICAL
within a couple hundred feet of the Colorado River (to the south). We understand the
subject site is located within the river flood plane and for that reason is not suitable to
support on site wastewater absorption. Therefor a system to collect wastewater using a
buried and pumped tank will be used.
PROPOSED CONSTRUCTION
Proposed construction includes two mobile/prefabricated offices approximately
58'x13'4". Construction will be one story, wood framed structures with sheet metal
sheathing and no below grade/basement areas. Foundation support is provided by the
existing iron frame of the structure and a continuous spread footing. Foundations are
considered to be adjustable to allow more movement than other traditional structures.
The structures will be anchored to the foundations. There will be one buried tank to
convey waste disposal. This buried tank will be located within the 100 year flood plan so
ballast design will be necessary. We are requested to use test pits as opposed to
exploratory borings in order to reduce costs and to reduce timing. Care should be taken to
avoid locations of all future structures with the test pits and to place backfill in a well
compacted manner, after this investigation. This is to help mitigate potential of damage
caused by settlement of test pit backfill. If proposed construction is different than what is
described above, we should be notified so that we can re-evaluate the recommendations
given.
25028 Hwy 6&24: 5-19-20
Rifle, Colorado
GEG Job No. 4,411
3
GEOTECHNICAL
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SUBSURFACE CONDITIONS
Subsurface conditions at the site were investigated by observing, sampling and
testing the soils encountered in two exploratory test pits. Locations of the exploratory test
pits are shown on Fig. A-2. Summary logs of the soils found in the exploratory test pits
and field penetration resistance tests are presented on Figs. A-3 and A-4. Subsurface
conditions encountered in two test pits consisted of 4 to 6 feet of clayey, gravelly sand
variable fill with cobbles underlain by silty, sandy clay variable fill with cobbles to the
maximum depth of 10 feet below ground surface. The clayey, gravelly sand variable fill
with cobbles was moist, brown and tan. The silty, sandy, gravelly clay variable fill with
cobbles was very moist to wet, brown and grey. Groundwater was encountered in TP -2 at
8 feet below ground surface at time of sampling.
One clayey, gravelly sand sample from TP -1 at 1-5 feet depth tested had a
moisture content of 12.0 percent, was found to be non -liquid and non -plastic and had 48
percent passing the No. 200 sieve (silt and clay sized particles). One clayey, sandy gravel
sample form TP -2 at 1-5 feet depth tested had a moisture content of 6.9 percent, a liquid
limit of 26, a plasticity index of 9 and had 22 percent passing the No. 200 sieve (silt and
clay sized particles). One silty, sandy, gravelly clay sample from an imported source
tested had a moisture content of 7.4 percent, a liquid limit of 24, a plasticity index of 6,
was found to have a maximum dry density of 117.8 pcf, an optimum moisture of 13.5
percent, had 51 percent passing the No. 200 sieve (silt and clay sized particles) and had
25028 Hwy 68 xd: 5-19-20
Rifle. Colorado
GEG Job No. 4.411
4
111' GEOTECHNICAL
L.NI_iINLEHNh, [IFRoi.i1'
400 ppm water soluble sulfates. Results of laboratory testing are shown on Appendix B
and summarized on Table I.
FOUNDATION RECOMMENDATIONS
This investigation indicates subsurface conditions at foundation levels included
variable man made fill consisting of interlayered clayey sand and sandy clay with
movement potential. Recommendations for foundations placed on at least 2 feet of well
compacted fill are presented herein. These criteria were developed from analysis of
field and laboratory data and our experience.
Spread Footing Foundation
Spread footing foundations bearing on well compacted native clay
subgrade and at least 2 feet of well compacted, well graded, granular
structural fill can be designed for a maximum allowable soil bearing
pressure of 3,000 pounds per square foot (psf). If soft or yielding soils are
found in excavation conditions may require stabilization such as a geogrid
product and crushed rock. Actual stabilization will be dependent on actual
conditions encountered. We recommend a minimum continuous footing
width of 18 -inches and minimum isolated pad of 30 inches square.
The completed excavation, within 2 feet horizontally beyond foundation
areas, should be scarified a depth of 10 -inches, moisture conditioned to
within 2 percent of optimum moisture content and compacted to at least
95 percent of standard Proctor maximum dry density (ASTM D698) prior
to forming. If loose or yielding conditions are encountered in the open
excavation, they should be removed and replaced with well compacted
structural fill. The excavation bottom proof roll using a heavy pneumatic
25028 Fiwy 6&24. 5.19.20
wne, Colorado
GEG Job No. 4,411
s
U!' GEOTECHNICAL
GiivLE: aiN i_n_iP
tired vehicle such as a front end loader with full bucket and compaction
testing show suitable subgrade preparation. Structural fill may be placed in
10 inch maximum thickness loose lifts, moisture conditioned to within 2
percent of optimum moisture and compacted to at least 95% of maximum
modified Proctor (ASTM D1557) dry density. Fill materials should be well
graded, less than 6 -inches diameter and less than 30 percent passing the
No. 200 sieve. A CDOT Class 6 aggregate base course will meet these
criteria and is recommended. We understand the client intends to import a
material from a nearby stockpile to meet this recommendation. Our
representative should be called to test compaction of subgrade and each
foot of structural fill, prior to forming.
3. Exterior walls must be protected from frost action. We understand there is
a 36 -inch minimum frost depth in Garfield County area. We recommend
referring to the local building code for frost protection requirements.
4. Completed excavations should be inspected by a representative of our
firm, testing for compaction and each foot of fill placed should be tested to
demonstrate proper compaction prior to placing the next lift of fill to
confirm that the soils are as anticipated from the exploratory borings and
to test compaction.
FLOOR SYSTEMS RECOMMENDATIONS
We believe the near surface soils, which will support slab -on -grade floors, exhibit
movement potential. Movement is expected for slabs bearing on these soils. Some
movement must be assumed from an increase in moisture by site and adjacent area
development and associated landscaping, irrigation and storm drainage. To our
knowledge, the only reliable solution to control floor movement is the construction of a
structurally supported floor with at least a 12 -inch (likely 36 -inch or greater) air space
between the floor and subgrade. In our opinion, structural floors should be used in all
25028 Hwy 88,24: 5-19-20
Rifle, Colorado
GEG Job No. 4,411
B
GEOTECHNICAL
areas. We understand structurally supported floors will be used in all areas.
BELOW -GRADE CONSTRUCTION
No below -grade construction is anticipated at this site except for the proposed
waste collection tank. Ballast will be required for the underground tank, and as included
in the proceeding section.
FOUNDATION DESIGN
See Appendix Fig. C-1 for foundation design.
BALLAST DESIGN
See Appendix Fig. C-2 for Ballast design.
CONCRETE
One soils sample from the import material was tested for water-soluble sulfates.
This sample had a sulfate concentration of 400 ppm, a moderate exposure level. We
recommend following the American Concrete Institute (ACI) guidelines for sulfate
resistant cement. ACI recommends a Type II, IP(MS) or IS(MS) cement be used for
25020 Hwy 0624: 5-70-20
RIRe, Colorado
GEG Job No. 4,411
7
GEOTECHNICAL
I F-NGIINF. G,POLIP
concrete that comes into contact with soils that have a moderate effect on concrete. In
addition, concrete should have a maximum water -cement ratio of 0.50 and minimum
compressive strength of 3,750 psi.
SURFACE DRAINAGE
Performance of foundations and concrete flatwork is influenced by surface
moisture conditions. Risk of wetting foundation soils can be reduced by carefully
planned and maintained surface drainage. Surface drainage should be designed to
provide rapid runoff of surface water away from the proposed construction. We
recommend the following precautions be observed during construction and maintained
at all times after the construction is completed. If these recommendations are not
followed, more movement and damages are likely.
The ground surface surrounding the exterior of the building should be
sloped to drain away from the building in all directions. We recommend a
slope of at least 12 inches in the first 10 feet around the structure, where
possible. In no case should the slope be less than 6 inches in the first 5
feet. The ground surface should be sloped so that water will not pond
adjacent to the structure.
2. Backfill around foundation walls should be moistened and compacted.
3. Roof downspouts and drains should discharge well beyond the limits of all
backfill. Splash blocks and downspout extenders should be provided at all
discharge points.
25028 Hwy 6624: 6-19-20
Rifle, Colorado
GEG Job No. 4,411
1111' GEOTECHNICAL
i_ucwr_ NIN
4. Landscaping should be carefully designed to minimize irrigation. Plants
used close to foundation walls should be limited to those with low moisture
requirements; irrigated grass and/or plants should not be located within 5
feet of the foundation. Sprinklers should not discharge within 5 feet of
foundations. Irrigation should be limited to the minimum amount sufficient
to maintain vegetation; application of more water will increase likelihood of
slab and foundation movements.
5. Impervious plastic membranes should not be used to cover the ground
surface immediately surrounding the structure. These membranes tend to
trap moisture and prevent normal evaporation from occurring. Geotextile
fabrics can be used to limit the weed growth and allow for evaporation.
CONSTRUCTION MONITORING
Geotechnical Engineering Group should be retained to provide general review of
construction plans for compliance with our recommendations. Geotechnical
Engineering Group should be retained to provide construction observation and testing
services during earthwork and foundation construction phases of the work. This is to
observe the construction with respect to the geotechnical recommendations, to enable
design changes in the event that subsurface conditions differ from those anticipated
prior to start of construction and to give the owner a greater degree of confidence that
the structure is constructed in accordance with the geotechnical recommendations.
25626 Hwy 9&24; 5.19.26
Rifle, Colorado
GEG Job No. 4,411
9
r GEOTECHNICAL
1 ENC-,INEENINLi LiF21:]LIF�
LIMITATIONS
The scope of services for this study does not include either specifically or by
implication any environmental or biological (such as radon, mold, fungi, bacteria, etc.)
assessment of the site or identification or prevention of pollutants, biological hazards,
hazardous materials or conditions. If the owner is concerned about the potential for
such contamination or pollution, other studies should be performed.
Two exploratory test pits were observed and sampled as excavated and backfilled
by the owner. Test pit backfill should be avoided with foundations and slabs. The test pits
are representative of conditions encountered only at the exact pit locations. Variations in
the subsoil conditions not indicated by the pits are always possible. Our representative
should observe open foundation excavations to confirm subsurface conditions are as
anticipated from the exploratory test pits and foundations are prepared as recommended
herein. We should be called to test subgrade soils and structural fill materials and
compaction.
The scope of work performed is specific to the proposed construction and the
client identified by this report. Any other use of the data, recommendations and design
parameters (as applicable) provided within this report are not appropriate applications.
Other proposed construction and/or reliance by other clients will require project specific
review by this firm. Changes in site conditions can occur with time. Changes in
standard of practice also occur with time. This report should not be relied upon after a
25028 Hwy 8324: 5-19-20
RBIs, Colorado
GEG Job No. 4,411
10
GEOTECHNICAL
ENSINEET IVIG i3NJ ILIP
period of three years from the date of this report and is subject to review by this firm in
light of new information which may periodically become known.
We believe this investigation was conducted in a manner consistent with that level
of care and skill ordinarily used by geotechnical engineers practicing in this area at this
time. No other warranty, express or implied, is made. If we can be of further service in
discussing the contents of this report or the analysis of the influence of the subsurface
conditions on the design of the residence, please call.
Sincerely,
Grand Valley Consulting, LLC dba
GEOTECHNICAL ENGINEERING GROUP
Chris Hill, E.I.T.
Staff Engineer
Reviewed By:
John Withers, P.E.
Engineer
(1 copy emailed)
25026 Hwy 6824: 5-19-20
Rifle, Colorado
GEG Job No. 4,411
• 30324
itP v-19-2020 ,601+4
S/OPdM. t'
11
APPENDIX A
FIELD EXPLORATION
Ariobit
Colorado River
Note: This figure was
prepared based on an
image from Bing maps.
Project Manager.
FPW
Project No.
4,411
Drawn by:
cdh�
Client:
Shawn Moody
Scale:
GRAPHIC
File Name:
4411.VMAP
Date:
5/13/2020
Ij GEOTECHNICAL
1 rNL.IINLL.:I:INL, Ltitu.]F
3510 Ponderosa Way Grand Junction, Colorado 61506
P [970] 261 3415 joNwrs@goolochnicnlpmup.not
VICINITY MAP
25028 Highway 6&24
Rifle, Colorado
Fig
A-1
TP -1
and location of waste
collection tank
Nommoolli
t
pproximate location
of proposed office
MI6
pproximate location
of proposed office
NOTE: THIS FIGURE WAS PREPARED BASED ON AN IMAGE
FROM BING MAPS, DIAGRAM I6 FOR GENERAL LOCATION
ONLY, AND 16 NOT INTENDED FOR CONSTRUCTION
PURPOSES
- Indicates location of exploratory pits.
Riled Manager:
JPW
Drown by.
CDH
ProJntlio,
4.411
gamic
N,7.S
FIIRNamr
BPL.N
ort.
5!13!2020,
GEOTECHNICAL
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9510 Poge,m Wry Onntl Jundal Coln. 91506
PH F76 291-3416 folthm®aeaaM1nkYgrap nal
LOCATIONS OF EXPLORATORY BORINGS
FIG No.
25028 Highway 6&24
Rifle, Colorado
A-2
0
5
10
` LOCATION:
DRILLER'
DEPTH
DATE:
DIAMETER
See Figure 2 __ _ _
ELEVATION:
LOGGED
HOURS:
CAVING:
10 Ft
BY
*
L
—
JW
Owner
TO WATER> INITIAL: 4 NATD _ AFTER 24
4/24/2020 DEPTH TO
backflll
-
12'x21' TOTAL DEPTH
k
—
Description
1
c9
y
S
so
,;e
a
Notes
Variable man made fill, sand, clayey, gravelly,
cobbles, moist, brown and tan
Cr
3'
5'
dpt
dpt
dpt
20/3
7/12
7/12
Bulk sample from 1-5'
_
Variable man made fill, clay, silty, sandy, cobbles,
very moist, brown and grey
7'
10'
dpt
dpt
4/12
7/12
Organics notes
Total depth 10 feet
This information pertains only to this borino and should not be Interpreted as belnp indlcltive of the site.
Project No.: 4,411
Client: Shawn Moody
Date: 511312020
,' GEOTECHNICAL
ENGINEERING GROUP
3510 Ponderosa Way, Grand Junction, Colorado 81506
(970) 261-3415
LOG OF EXPLORATORY TEST PIT TP -1
25028 Highway 6&24
Rifle, Colorado
Fig
A-3
0
5
10
LOCATION:
DRILLER:
DEPTH
DATE:
DIAMETER
See Figure 2
ELEVATION:
LOGGED
HOURS:
CAVING:
8 Ft
Br
i
-
Owner
JW
TO WATER> INITIAL' 8' ATD AFTER 24
backfill
4)24/2020 DEPTH TO
L -
12's21' TOTAL DEPTH
e
11
Description
O
5r1
mppp
g i-
r
m 1
Notes
Variable man made fill, sand, clayey, gravelly, cobbles,
moist and brown
0'
3'
dpt
dpt
20/7
20/12
Bulk sample from 1-5'
Variable man made fill, clay, silty, sandy, gravelly,
cobbles, wet, brown and grey
5'
8'
dpt
dpt
6/12
4/12
Organics noted
Total depth 8 feet
This information pertains only to this boring and should not be interpreted as being indicative of the site.
Project No,: 4,411
Client: Shawn Moody
Date: 5113(2020
ICU GEDTECHNICAL
I. ENDINEE'k'.!!v!l
3510 Ponderosa Way, Grand Junction, Colorado 81506
(970) 261-3415
LOG OF EXPLORATORY TEST PIT TP -2
25028 Highway 6&24
Rifle, Colorado
F,g
A-4
APPENDIX B
LABORATORY TESTING
Laboratory Testing
Soil samples were tested in the laboratory to measure their dry unit weight, natural water content,
grain size distribution (sieve analysis) and plastic characteristics (Atterberg Limits).
The test results are included in Appendix B.
Descriptive classifications of the soils indicated on the boring logs are in accordance with the
enclosed General Notes and the Unified Soil Classification System. Also shown are estimated
Unified Soil Classification Symbols. A brief description of this classification system is attached to
this report. All classification was by visual manual procedures. Selected samples were further
classified using the results of gradation and Atterberg limit testing.
FIG. B-1
Grand Valley Consulting, LLC dba
GEOTECHNICAL
PHYSICAL PROPERTIES- GRADATION
Job No.: 4,411 Location: TP -1 at 1-5 Initiated By: CH Date: 4/24/2020
Soil Description: Sand, clayey. gravelly (SC)
GRADATION
CUMMULATIVE PERCENT
PASSING (%)
3" 100
1.5" 100
3/4" 82
3/8" 79
#4 78
#e 77
#16 76
#30 74
#50 71
#100 64
#200 48
#200 WASH 48 % Gravel 22 %
Moisture Content 12.0 % Sand 30 %
Clay 48 %
Fig. B-2
Grand Valley Consulting, LLC dba
11IGEOTECHNICAL
P�IGiNL_.! I'ilNu C'RL!L
PHYSICAL PROPERTIES- GRADATION
Job No. 4,411 Location: TP -2 at 1-5 Initiated By: CH Date: 4/24/2020
Soil Description: Gravel, clayey, sandy (GM)
CUMMULATIVE PERCENT
GRADATION PASSING (%)
3" 100
1.5' 54
3/4" 51
3/6" 44
#4 39
#8 37
#16 36
#30 33
#50 29
#100 26
#200 22
#200 WASH 22 % Gravel 61 %
Moisture Content 6.9 % Sand 17 %
Clay 22 %
Fig. B-3
Grand Valley Consulting, LLC dba
Job No.:
1!I GEOTECHNICAL
C�`IGlilvi;i3F�l, lC,, GROLIP
PHYSICAL PROPERTIES- GRADATION
4,411 Location: Import
Soil Description: Clay, silty, sandy, gravelly (CL.)
GRADATION
Initiated By: CH Date: 4/24/2020
CUMMULATIVE PERCENT
PASSING (%)
3" 100
1.5" 100
3/4" 100
3/8" 95
#4 90
#8 87
#16 85
#30 81
#50 76
#100 65
#200 51
#200 WASH 51 % Gravel 10 %
Moisture Content 7.4 % Sand 39 %
Clay 51 %
Fig. B-4
140
130
120
110
100
MOISTURE -DENSITY
RELATIONSHIP TEST REPORT
Project No.: 4,411
25028 Hwy 6&24
Source: Import
Remarks:
Elev./Depth:
MATERIAL DESCRIPTION
Description: Clay, silty, sandy gravelly ICL)
Classification = USCS: ICL)
Nat. Moist. = 7.4%
Liquid Limit = 24
fir GEOTECHNICAL
ENGINEERING GRCLIP
Date: 4-24-2020
Sample No. 1
AASHTO
SP.G. _
Plasticity Index = 6
<No.200=51
MATERIAL DESCRIPTION
Maximum Dry Density = 117,8 pcf
Optimum Moisture = 13.5%
Test specification:
ASTM D 698-07 Method B Standard
B
2.7
2.6
100% SATURATION CURVES
FOR SPECIFIC GRAVITY EQUAL TO:
90
80
70
0
r
AP -
5
10 15 20 25
Water content,
30
35
40
Fig. B-5
iI' GEOTECHNICAL
i-.ir,HvH-L:RINI; ',Ruin'
Job No. 4,411 25028 Highway 6&24
TABLE 1
SUMMARY OF LABORATORY TEST RESULTS
Hole
Depth
(feet)
Moisture
(%)
Dry
Density
(pcf)
Atterberg Limits
Moisture -Density Relationship
Passing
No. 200
Sieve (%)
Water
Soluble
Sulfatesp
(Wm)
Soil Type
Liquid
Limit
(%)
Plasticity
Index
(%)
Maximum Dry
Density (pcf)
Optimum Moisture
(%)
TP -1
1-5
12.0
NL
NP
48
Sand, clayey gravelly (SC)
TP -2
1-5
6.9
26
9
22
Gravel, clayey sandy (GM)
Import
7.4
24
6
117.8
13.5
51
400
Clay, silty, sandy gravelly (CL)
Page 1 of 1
APPENDIX C
DESIGN DETAILS
64'
continuous footing pad: 18" wide x 10" thick, centered beneath prefabricated structure frame, x2 (typical each structure)
1wo (2) #4 bars
continuous 32"
minimum lap
length
#4 bar x 10' long,
field bend to
attach to prefab
hold down struts.
min 6" x 1/4" fillet
weld to each
strut. Space as
necessary for
each hold down
strut, -9' O.C.
A' 14'
A'
Plan View : N.T.S.
Section A':A' : N.T.S.
Project Manager.
Drawn by:
JpIN,
cdh
Project No.
4,411
Scale:
GRAPHIC
Cgent:
Shawn Moody,
Flle Name:
4411.fplan
Date:
5/15/2020
10"
y
1111 GEOTECHNICAL
ENGINEERING GRriLJP
3510 Ponderosa Way Grand Junction, Colorado 91506
P 19701 261 3415 jwhhers@geotechnicalgroup,nel
'.
30324
e
5-19-2020 r; ,
voo
FOUNDATION PLAN
Fig
25028 Highway 6&24
Rifle, Colorado
C-1
Soil Profile:
Site specific soil investigation "GEOTECHNICAL SOILS INVESTIGATION, 25028 Highway 6&24, Colorado" dated
May 16, 2020, performed by Geotechnical Engineering Group under Job No. 4,411.
Subsurface conditions encountered in two test pits consisted of variable existing man made fill.
Minimum 2' existing soil must be removed, recompacted and tested prior to forming.
CONCRETE:
1. ALL CONCRETE SHALL DEVELOP 3,750 PSI MINIMUM COMPRESSIVE STRENGTH AT 28 DAYS FROM
POUR.
2. ALL CONCRETE SHALL USE MODIFIED TYPE II PORTLAND CEMENT. FLY ASH SUBSTITUTION IS
PERMITTED PER APPROVAL OF ENGINEER.
3. ALL REINFORCING SHALL CONFORM TO ASTM A615, GRADE 60. REINFORCING SHALL BE FREE OF
DIRT, RUST, OR ANY OTHER MATERIAL WHICH MIGHT INHIBIT ITS BOND TO CONCRETE.
4. LAP SPLICES SHALL BE A MINIMUM OF 36 BAR DIAMETERS. MAKE ALL BARS CONTINUOUS AROUND
CORNERS.
5. DETAIL BARS IN ACCORDANCE WITH A.C.I. BUILDING CODE REQUIREMENTS FOR STRUCTURAL
CONCRETE.
6. REINFORCEMENT PROTECTION SHALL BE AS FOLLOWS: FORMED CONCRETE EXPOSED TO EARTH =
3" FORMED CONCRETE NOT EXPOSED TO EARTH = 1 1 2 "
7. ALL CONSTRUCTION JOINTS SHALL BE APPROVED PER ENGINEER.
8. ALL CONCRETE FOOTING AND WALL POURS SHALL BE MECHANICALLY VIBRATED.
FOUNDATION:
1. OWNER/CONTRACTOR SHALL VERIFY ALL DIMENSIONS AND NOTIFY ENGINEER OF ANY
DISCREPANCIES PRIOR TO PLACEMENT OF FORMS.
2. THE FOUNDATION SHALL BEAR ON WELL COMPACTED SUBGRADE AND WELL COMPACTED EXISTING
FILL, TESTED AS DESCRIBED IN THE REFERENCED SOIL REPORT.
3. THE ENGINEER SHALL BE NOTIFIED A MINIMUM OF 48 HOURS IN ADVANCE FOR INSPECTION OF THE
FOUNDATION HOLE WHEN EXCAVATION IS COMPLETE. FURTHER INSPECTION PER THE LOCAL
BUILDING JURISDICTION MAY BE REQUIRED.
4. THE ENGINEER SHALL BE NOTIFIED IF ADVERSE OR POOR SOIL CONDITIONS ARE ENCOUNTERED
UPON EXCAVATION. FURTHER ENGINEERING MAY BE REQUIRED.
5. THIS FOUNDATION DESIGN IS BASED ON GEOTECHNICAL ENGINEERING GROUP SOIL INVESTIGATION
JOB NO. 4411. FOLLOW ALL GEOTECHNICAL RECOMMENDATIONS. CONTACT ENGINEER IF THEIR ARE
ANY QUESTIONS OR ANY CHANGES DESIRED PRIOR TO PROCEEDING.
30324
5-19-2020 �.'►a�+,
aoa°°
t t
Pilled Manager.
JPW
Orme by: CDH
Project No.
4.411
scow: N.T.S
Flle Name:
NOW
Oats;
5/16/2020
1911 GEOTECHNICAL
GN13II'JELRIiNG LIkt LIP
3510 me Way Brand JwNm [daeaa 01500
P13 010013015 iMd'M9mbcFnraanauaM
FOUNDATION NOTES
25028 Highway 6&24
Rifle, Colorado
FIG No.
C-2
11 TOP SLAB
REINFORCING
WNiR 9X12
D23.3XD15
4" COVER TO
BOTTOM
8' 6"
A
a
INSPECTION PORT
4"X16"
BLOCKOUT
SECTION A -A
12" uv. . 'u. vC w,A4.4 `r'# fc. 3wcg04-1
11,44/pt L 1' /CP (AS 6 a� !#1;Z:5'� a
(dg 1-(g 4 - Wk Orsi ru
NOTES:
1, ASTM C1227, 4,500
CONCRETE,
AFF
RATED, MAXIMUM BURY DEPTH FROM TOP TO C
SURFACE
2. BASE AND WALLS POURED MONOLITHIC WITH
SEPARATE TOP SLAB AND LDS
3. TANK USES STANDARD 21" DIAMETER RISER
SECTION WITH TANK UDS IF REQUIRED
4. ALL INLETS AND OUTLETS HAVE A POLYLOK PIPE
SEAL FOR 4" PVC, SDR 35 OR SCHEDULE 40
5. INLET AND OUTLET REQUIRE A TUF-TITE TB -4
BAFFLE INSTALLED ON THE INSIDE OF TANK, REFER TO
STATE AND LOCAL CODES
#4 L BAR 12`X12",
TWO IN EACH
CORNER, 12" DOWN
FROM TOP, 8" UP
FRO.4 BOTTOM (8
TOTAL)
WALLS/FLOOR
REINFORCING
WWR 6X6
W2.9XW2.9
CENTER IN
WALLS/FLOOR
6' 114"
SIDE VIEW
!no FORTERRA
-
9455 BOSTON COURT
HENDERSON, CO 50640
303-B53-8053
FORTERRA — GRAND JUCTION
STANDARD DRAWINGS
1500 GALLON PRECAST SEPTIC TANK
WITH CAST IN BAFFLE
SHIS SAR Is ONE NM ON CI11MMAL 11M* G
0
1"
i
DOS 9M IS NOT WE II AAAIST SCALE
e
l(C
NONE
Wi
101Ti
1-14-20
-ler
lwr 3OF3
1500 Gallon Precast Septic
tank with cast in baffle
[Ground Level
Braided wire
minimum 7/16"
diameter, situate
over tank to
attach each block
picking eye
'Three (3) 2'x2'x6'
Portland cement
concrete blocks
(148pcf) each
side, typical
•
ir N-♦' , ri
0
30324
5-19-2020 :
444
ONAL
Prajad Minapor.
Drawn by:
Client:
Shawn Mood
Project No.
4,411
Scale:
cdh
GRAPHIC
File Name:
4411.folan
Date:
5/15/2020
GEOTECHNICAL
LNL INLERING GROUP
3510 Ponderosa Way Grand Junction, Colorado 61506
167012613415 Jwithers@geotechnlcalgroup.net
Braided wire
7/16" minimum
diameter, situate
over tank to
attach each block
picking eye
Three (3) 2'x2'x6'
Portland cement
concrete blocks
(148pcf) each
side, typical
TANK BALLAST PLAN
25028 Highway 6&24
Rifle, Colorado
Fig
C-3
APPENDIX D
SUPPORTING DOCUMENTS
GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon -1 3/e" I.D., 2" O.D., unless otherwise noted
ST: Thin -Walled Tube — 2" O.D., 3" O.D., unless otherwise noted
RS: Ring Sampler- 2.42" I.D., 3" O.D., unless otherwise noted
DB: Diamond Bit Coring - 4", N, B
BS: Bulk Sample or Auger Sample
HS:
PA:
HA:
RB:
WB
Hollow Stem Auger
Power Auger (Solid Stem)
Hand Auger
Rock Bit
Wash Boring or Mud Rotary
The number of blows required to advance a standard 2 -inch O.D. split -spoon sampler (SS) the last 12 inches of the total 18 -inch penetration
with a 140 -pound hammer falling 30 inches is considered the "Standard Penetration" or "N -value".
WATER LEVEL MEASUREMENT SYMBOLS:
WL: Water Level WS: While Sampling BCR: Before Casing Removal
WCI: Wet Cave in WD: While Drilling ACR: After Casing Removal
DCI: Dry Cave in AB: After Boring N/E: Not Encountered
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times
and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low
permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have
more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained
Soils have Tess than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if
they are slightly plastic or non -plastic. Major constituents may be added as modifiers and minor constituents may be added according to
the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative
density and fine-grained soils on the basis of their consistency.
CQN$I$TENCY QF FINE-GRAINED SOILS
Unconfined Standard Penetration
Compressive or N -value (SS)
Strength, Qu, vsf Blows/Ft.
<500 0-1
500 — 1,000 2 - 4
1,000-2,000 5-8
2,000 — 4,000 9 - 15
4,000 — 8,000 16 - 30
8,000+ > 30
Consistency
Very Soft
Soft
Medium Stiff
Stiff
Very Stiff
Hard
RELATIVE PROPORTIONS OF SAND AND GRAVEL
Desc rloti ve Te rm(sl Percent of
of other constituents Dry Weight
Trace < 15
Wdh 15 — 29
Modifier z 30
RELATIVE PROPORTIONS OF FINES
Descriptive Term(0, Percent of
of other constituents Dry Weighs;
Trace < 5
With 5-12
Modifier > 12
RELATIVE DENSITY QF COARSE-GRAINED SOILS
Standard Penetration
or N -value (551 Relative Density
Blows/Ft
0-3
4-9
10-29
30-50
> 50
GRAIN
Major Component
of Sample
Boulders
Cobbles
Gravel
Sand
Silt or Clay
Very Loose
Loose
Medium Dense
Dense
Very Dense
SIZE TERMINOLOGY
PartIcle Size
Over 12 in. (300mm)
12 in. to 3 in. (300mm to 75mm)
3 in. to #4 sieve (75mm to 4.75mm)
#4 to #200 sieve (4.75 to 0.075mm)
Passing #200 Sieve (0.075mm)
PLASTICITY DESCRIPTION
Term Plasticity
Index
Non -plastic 0
Low 1-10
Medium 11-30
High > 30
FIG. D-1
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A
Soil Classification
Group Group Name
Symbol
Coarse Grained Solis:
More than 50% retained
on No. 200 sieve
Gravels:
More than 50% of
coarse
fraction retained on
Jdo. 4 sieve
Sands:
50% or more of coarse
Clean Gravels:
Less than 5% fines °
Cu a4 and 1.Ccs3E
GW
Cu <4 and/or 1 > Cc> 3E
GP
Gravels with Fines:
More than 12% fines°
Fines classify as ML or MH
GM
Fines classify as CL or CH
GC
Clean Sands:
Less than 5% fines °
Cu 26 and 15 Cc 530
SW
Cu<6and/or 1>Cc>30
SP
Well -graded gravel r
Poorly graded gravel'
Silty gravel r'°`"
Clayey gravel P6"
Well -graded sand'
Poorly graded sand,
fraction passes Sands with Fines:
No. 4 sieve More than 12% fines °
Fines classify as ML or MH
SM Silty sand°'
Fines Classify as CL or CH
SC Clayey send°•'6
Fine -Grained Soils:
50% or more passes the
No. 200 sieve
Inorganic:
Silts and Clays:
Liquid limit less than 50
Organic:
PI > 7 and olots on or above "A" line'
PI < 4 or plots below "A" line'
Liquid limit - oven dried
Liquid limit - not dried
< 0.75
CL
ML
OL
Lean Gay KL.W
Sileus
Organic day KLu'"
Organic silt KL3K°
Silts and Clays:
Liquid limit 50 or more
Inorganic:
PI plots on or above "A" line
PI plots below "A" line
CH
MH
Organic:
Liquid limit - oven dried
Liquid limit - not dried
< 0.75
OH
1 FatcleyKL'r
I Elastic Silt"•"
Organic clay K L -*P
I Organic silt KLv°
Highly organic soils:
Primarily organic matter, dark in
color, end organic odor
PT V Peat
A Based on the material passing the 3 -in. (75 -mm) sieve
° If field sample contained cobbles or boulders, or both, add "with cobbles
or boulders, or both" to group name.
° Gravels with 5 to 12% fines require dual symbols: GW -GM well -graded
gravel with silt, GW -GC well -graded gravel with clay, GP -GM poorly
graded gravel with silt, GP -GC poorly graded gravel with clay.
° Sands with 5 to 12% fines require dual symbols: SW -SM well -graded
sand with silt, SW -SC well -graded sand with clay, SP -SM poorly graded
sand with silt, SP -SC poorly graded sand with clay
(D30)2
E Cu = Deo(D10 Cc =
D10 x D80
F If soil contains >_ 15% sand, add "with sand" to group name.
° If fines classify as CL -ML, use dual symbol GC -GM, or SC -SM.
PLASTICITY INDEX (PI)
00
50
40
30
20
10
7
4
0
0
Far class Iftcal lsn of IIne-gratnad
walla and (Ina -grained fraction
et hoarse-gralnad soils
Equation of "A" - line
Horizontal al P1=4 to LL=255.
then PI=0.73 (LL -20)
Equallon 01"U" - lino
Va8Vaol M 11.16 to Pt.7
then PI=0.9 (LL -8)
H If fines are organic, add "with organic fines" to group name.
If soil contains z 15% gravel, add "with gravel" to group name.
If Atterberg limits plot in shaded area, soil is a CL -ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add "with sand" or "with
gravel," whichever is predominant.
L If soil contains z 30% plus No. 200 predominantly sand, add "sandy"
to group name.
ra If soil contains z 30% plus No. 200, predominantly gravel, add
"gravelly" to group name.
H PI > 4 and plots on or above "A" line.
° PI < 4 or plots below "A" line.
P PI plots on or above "A" line.
° PI plots below "A" line.
ML or OL
10 16 20 30 40 50 60
MH or OH
LIQUID LIMIT (LL)
70 B0 90 166 110
Fig. D-2
GENERAL NOTES
Description of Rock Properties
WEATHERING
Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if
crystalline.
Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken
face show bright. Rock rings under hammer if crystalline.
Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may
contain clay. In granitoid rocks some occasional feldspar crystals are dull and discolored.
Crystalline rocks ring under hammer.
Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most
feldspars are dull and discolored; some show clayey. Rock has dull sound under hammer and
shows significant loss of strength as compared with fresh rock.
Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and
discolored and majority show kaolinization. Rock shows severe loss of strength and can be
excavated with geologist's pick.
Severe All rock except quartz discolored or stained. Rock "fabric" clear and evident, but reduced in
strength to strong soil. In granitoid rocks, all feldspars kaolinized to some extent. Some
fragments of strong rock usually left.
Very severe All rock except quartz discolored or stained. Rock "fabric" discemible, but mass effectively
reduced to "soil" with only fragments of strong rock remaining.
Complete Rock reduced to "soil". Rock "fabric" not discernible or discernible only in small, scattered
locations. Quartz may be present as dikes or stringers.
HARDNESS (for engineering description of rock — not to be confused with Moh's scale for minerals)
Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several
hard blows of geologist's pick.
Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach
hand specimen.
Moderately hard Can be scratched with knife or pick. Gouges or grooves to'/ in. deep can be excavated by hard
blow of point of a geologist's pick. Hand specimens can be detached by moderate blow.
Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be
excavated in small chips to pieces about 1 -in. maximum size by hard blows of the point of a
geologist's pick.
Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces
several inches in size by moderate blows of a pick point. Small thin pieces can be broken by
finger pressure.
Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1 -in. or more in
thickness can be broken with finger pressure. Can be scratched readily by fingernail.
Joint, Etedding and Foliation Spacing In Rock •
Spacing
Joints
Bedding/Foliation
Less than 2 in.
r
Very close
Very thin
2 in. — 1 ft.
Close
Thin
1 ft. — 3 ft.
Moderately close
_ Medium
3 fI. — 10 ft.
1
Wide
Thick
More than 'ID ft.
I
Very wide
Very thick
FIG. D-3
Rock Quality Des gr►ator (ROD) b
Joint Openness Descriptors
ROD„ as a percentage
Diagnostic description
Openness
Descriptor
Exceeding 90
90 — 75
75 — 50
50 — 25
Less than 25
Excellent
Good
Fair
Poor
Very poor
No Visible Separation
Less than 1/32 in.
1/32 to 1/8 in.
1/8 to 3/8 in.
3/8 in. to 0.1 ft.
Greater than 0.1 ft.
Tight
Slightly Open
Moderately Open
Open
Moderately Wide
Wide
a Spacing refers to the dIstanco nnrmel to the planes, of the described feature, which are parel to each olher or nearly so.
b. RQD (given as a percentage) = length of core in pieces 4 in. and longer/length of run.
References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface
1,_}rveslioalion for Design and Consrruclion of Foundations of Bulldrnos. New York: American Society of Civil
Engineers, 1976.
U.S. Department of the Interior, Bureau of Reclamation Enuineerino G9oIQ4v Field Mensal
FIG. D-4