HomeMy WebLinkAboutAppendD_05_NB-Ramp_ExchangePropRSS_GeotechRecommend_08142009
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Subsurface Conditions
Geotechnical conditions for the WSDOT Exchange Property area were established on the
basis of existing geotechnical explorations supplemented by 3 new explorations advanced
by Icicle Creek Engineers in support of the Renton Stage 2 Project. The new boring logs
were used with the existing site soil information to develop geotechnical parameters for
analysis and design of RSS slope.
Geotechnical Explorations
The following exploration locations were used in the evaluation of the site conditions and in
the creation of soil profiles beneath the RSS. The boring and test pit logs were also used to
develop geotechnical parameters for analysis and design of the RSS. The source of the
exploration information is summarized in Table 1. Figure 2 shows the approximate
locations of the explorations. Figure 3 shows the interpreted typical subsurface. Copies of
the exploration logs are included in Attachment B.
TABLE 1: WSDOT EXCHANGE PROPERTY EXPLORATION LOCATIONS
Exploration Location Type Source
B-1 Boring Icicle Creek Engineers, Inc., 2005
B-2 Boring Icicle Creek Engineers, Inc., 2005
B-3 Boring Icicle Creek Engineers, Inc., 2005
TP-1 Test pit Icicle Creek Engineers, Inc., 2005
TP-2 Test pit Icicle Creek Engineers, Inc., 2005
TP-3 Test pit Icicle Creek Engineers, Inc., 2005
TP-4 Test pit Icicle Creek Engineers, Inc., 2005
TP-5 Test pit Icicle Creek Engineers, Inc., 2005
TP-6 Test pit Icicle Creek Engineers, Inc., 2005
TP-7 Test pit Icicle Creek Engineers, Inc., 2005
TP-8 Test pit Icicle Creek Engineers, Inc., 2005
TP-12 Test pit Icicle Creek Engineers, Inc., 2005
TP-13 Test pit Icicle Creek Engineers, Inc., 2005
TP-14 Test pit Icicle Creek Engineers, Inc., 2005
TP-15 Test pit Icicle Creek Engineers, Inc., 2005
TP-16 Test pit Icicle Creek Engineers, Inc., 2005
515-4-06 Boring Geoengineers, 2007
CDB-6p-08 Boring Geoengineers, 2007
SRX-20-05 Boring Geoengineers, 2007
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TABLE 1: WSDOT EXCHANGE PROPERTY EXPLORATION LOCATIONS
Exploration Location Type Source
515-6-06 Boring Geoengineers, 2007
515-7-06 Boring Geoengineers, 2007
B-5 Boring Icicle Creek Engineers, Inc., 2009
B-10 Boring Icicle Creek Engineers, Inc., 2009
B-11 Boring Icicle Creek Engineers, Inc., 2009
Icicle Creek Engineers, Inc., “Report- Coal Mine Hazard Assessment and Preliminary Geotechnical Evaluation,
Renton Hill Property, King County Parcel Nos. 2023059085 and 0007200194/196, Renton, Washington,” June
10, 2005.
GeoEngineers, 2007, “Geotechnical Baseline Report I-405/1-5 to SR 169 Stage 2 – Widening and SR 515
Interchange, Renton, Washington,” September 7, 2007.
Icicle Creek Engineers, Inc., “Report, Geological Engineering Services, Coal Mine Hazard Assessment,
WSDOT Property, Renton, Washington,” May 11, 2009.
Interpreted Geotechnical Conditions and Groundwater Location
The existing WSDOT Exchange property is an undeveloped parcel of land located on the
hillside between I-405 and Cedar Avenue. Slopes vary from 5 to over 90 percent, with slope
lengths varying from 25 to over 100 feet. The site elevation varies from approximately 140
feet to 230 feet.
The general subsurface profile consists of colluvium/fill overlying residual soils weathered
from the Renton Formation overlying the Renton Formation. The colluvium/fill/residual
soils are difficult to distinguish from each other and are considered as one unit for the
analysis. The site is underlain by the Renton Formation sandstone bedrock. In the
southwest portion of the site there are deposits of materials consisting of mine tailings and
old municipal waste that are associated with the abandoned Renton Civic Dump site.
The general characteristics of the predominant geologic units are as follows:
• The colluvium/fill/residual soils vary from ~1 foot to 10 feet thick over the site. These
soils are generally medium dense and consist primarily of silty sand.
• The tailings/municipal waste thickness varies from a thin veneer to over 25 feet thick.
These soils are loose to medium dense and contain a wide variety of materials including
silt, sand, slag, ashes, glass, metal, debris, and other materials associated with municipal
waste disposal. Mine tailings may also be incorporated in this material, either as cover
soils, or as a result of previous mining activities that occurred in the same area.
• The Renton Formation consists of weak sandstone bedrock with occasional siltstone
layers and extends below the depth explored with borings at the site.
Boring log information indicates that groundwater was found generally in the Renton
Formation, below elevation 100 feet.
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Seismicity and Ground Motions
The Renton Stage 2 Project is being designed in accordance with WSDOT’s current seismic
design requirements. These requirements include use of a design earthquake that has a 7
percent probability of exceedance in a 75-year exposure period. The seismic ground motions
and liquefaction potential for this design earthquake are summarized below.
Seismic Ground Motions
Design peak ground acceleration (PGA) of 0.44g is used in analysis. This ground motion
was determined using the AASHTO ground motions hazard map and a site coefficient for
peak ground acceleration (Fpga) of 1.0 based on Site Class C site classification.
Per the WSDOT GDM (2008), a horizontal pseudo-static acceleration coefficient, kh = 0.22
(F*PBA/2) was used in the global stability analysis. Use of this reduced seismic coefficient
implies that several inches of permanent slope displacement is acceptable during the design
seismic event.
Liquefaction Potential
Soils at the project site below the water table are the sandstone bedrock; therefore,
liquefaction potential of site soils is very low. Surface water will be routed from the RSS
and fill to prevent infiltration and possible ponding of water within the compacted fill
layers and RSS.
Geotechnical Design
The design of RSS follows the steps outlined in Chapter 7 of FHWA Publication FHWA-
NHI-00-043, “Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and
Construction Guidelines,” by Elias, et al. (2001).
General Design Considerations
The general design considerations for this project are listed below.
• Traffic Surcharge assumed equivalent to 2.0 feet of soil surcharge (surcharge unit weight
= 125 pcf) = 125 pcf x 2 feet = 250 psf.
• Extensible (geosynthetic geogrid) reinforcement is to be used.
• A wrapped face is not required because the slope is shallower than 1.2(H):1(V) (GDM,
2008).
• Minimum length of reinforcing is 6 feet (GDM, 2008).
• Primary reinforcing shall be vertically spaced at 3 feet or less (GDM, 2008).
• Minimum long-term allowable strength of primary reinforcing = 1,250 lb/ft.
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COPYRIGHT 2009 BY I-405 CORRIDOR DESIGN BUILDERS • COMPANY CONFIDENTIAL
• Secondary reinforcing between layers of primary reinforcing shall be at a maximum
vertical spacing of 1 foot (GDM, 2008). Secondary reinforcing shall not be included in
the internal stability analysis of the RSS.
• Minimum long-term allowable strength of secondary reinforcing = 115 lb/in.
• Backfill within the reinforced zone of the RSS shall consist of Common Borrow, meeting
the requirements of WSDOT Standard Specifications Section 9-03.14(3), as modified in
the Project Technical Specification drafted for the RSS. As follows:
Sieve Size Percent Passing
3-inch 100
No. 4 100 - 20
No. 200 0 - 35
Geotechnical Material Properties
The following properties were used in the design of the RSS:
New Fill:
• Unit weight = 130 pcf
• Internal angle of friction = 36 degrees
• Cohesion (static case) = 0 psf
• Internal angle of friction (seismic case) = 34 degrees
• Apparent cohesion (seismic case) = 200 psf
Residual soil/colluvium/fill:
• Unit weight = 130 pcf
• Internal angle of friction = 36 degrees
• Cohesion (static case) = 0 psf
• Apparent cohesion (seismic case) = 200 psf
Renton Formation:
• Uniaxial compressive strength = 300 psi (43.2 ksf)
• Geologic strength index (GSI) = 40
• Intact rock constant (mi) for sandstone = 17
• Disturbance factor (D) for good quality excavation = 0.0
• Mohr-Coulomb fit (Hoek-Brown Criteria), internal angle of friction = 32 degrees
• Mohr-Coulomb fit (Hoek-Brown Criteria), cohesion (seismic and static cases) = 2100 psf
Municipal Waste:
• Unit weight = 115 pcf
• Internal angle of friction = 28 degrees
• Cohesion (static case) = 300 psf
• Apparent cohesion (seismic case) = 300 psf
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Reinforcement Length Requirements
Analyses were conducted at selected sections along the RSS to evaluate the minimum
reinforcement lengths (Lmin) required to satisfy stability requirements. The analytical results
were compared to GDM minimum acceptable criteria shown below.
• Sliding FS 1.5
• Global Stability (outside of reinforced zone) FS 1.5
• Compound Failure (through face of RSS) FS 1.5
• Internal Slope Stability (through the reinforcing) FS 1.5
• Lateral Squeeze (bearing failure) FS 1.5
• Seismic Stability FS 1.1
The above factors of safety assume that structures (e.g., residences) will be constructed on
the RSS fill in the future. For sliding, global stability, compound failure, internal stability,
and seismic stability evaluations, the computer program SLIDE (Rocscience, 2008) was used.
Lateral squeeze does not apply because the RSS is founded on competent bearing materials.
To achieve the required FS, a geogrid with minimum long-term design strength of 1,250
lb/ft, coupled with the reinforcement lengths summarized in Table 2, is required. The
length of reinforcing was generally controlled by a combination of static and seismic
stability. The approximate station extents for the different Lmin are summarized in Table 2.
All stations are based on a construction reference alignment CEDAR RW Line. For a given
embankment location, all reinforcing lengths are constant for the entire embankment height.
TABLE 2: REINFORCEMENT TABLE
Beginning
Station
Ending
Station
Minimum
Reinforcement
Length (Lmin)
Bottom Reinforcing
Elevation (ft)
Top Reinforcing
Elevation (ft)
10+35 10+75 25 200 Varies, max 220
10+75 11+50 40 194 220
11+50 11+75 40 182 220
11+75 12+50 50 172 222
12+50 13+00 45 172 222
13+00 13+75 40 176 222
13+75 14+50 40 172 224
14+50 15+45 40 172 226
15+45 15+95 40 172 Varies, max 226
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Settlement
Due to the granular consistency and/or heavily overconsolidated nature of the existing soils
and bedrock, settlement is anticipated to be elastic in nature and is expected to occur during
embankment construction.
Construction Requirements
The construction of the RSS and backfill require careful planning and construction control,
including oversight by the project geotechnical engineer, to assure that the slope is
constructed in such a manner that short- and long-term stability requirements are met. The
following subsection summarizes key construction requirements. Specific requirements for
construction of the RSS are included in the technical specification Reinforced Soil Slope, I.5:1
(Horizontal to Vertical) Slopes, included as Attachment C to this memorandum.
Subgrade Preparation and Ground Improvement
Before placement of fill or backfill for the RSS, all surface vegetation, topsoil, trash,
construction debris, or other deleterious materials shall be removed from beneath the
reinforced soil zone and properly disposed of offsite. Loose, soft, or wet material should
also be removed and replaced with competent backfill. All sharp stone protrusions that
could damage the reinforcing should also be removed.
The subgrade within the footprint of the reinforced soil volume should be graded level as
required for construction, proof rolled, and compacted to 95% of Standard Proctor Density
(ASTM D698, AASHTO T99). Fill shall be keyed into the existing slope following Section 2-
03.3(14) “Hillside Terraces” of the Standard Specifications.
Because of the variable nature of the site fill, field review and approval of the RSS subgrade
and construction site preparation below the RSS by the project geotechnical engineer is
required. Overexcavation may be required in areas where actual subgrade conditions do
not meet the design recommendations. Depth and extent of overexcavation will be as
directed by the geotechnical engineer.
Fill and Backfill Requirements
Backfill within the reinforced zone of the RSS shall consist of Common Borrow, meeting the
requirements the RSS Project Technical Specification. The borrow source is expected to be
the Renton Formation that is excavated to construct other project elements. The backfill
material must be free of organics and other deleterious materials. The maximum particle
size should be 3 inches. If wet-weather construction makes it difficult to achieve the
required moisture and compaction density, Select Borrow (Section 9-03.14(2)) or Gravel
Borrow (Section 9-03.14(1)) shall be used in lieu of Common Borrow.
Backfill in the reinforced zone shall be placed in loose lifts of maximum 12-inch thickness
and compacted to 95% of maximum density in accordance with the requirements of Section
2-03.3(14)C, Method C, of the WSDOT Standard Specifications and the project-specific
technical specification (see Attachment C).
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Backfill behind the reinforced zone shall be Common Borrow in accordance with the
requirements of Section 9-03.14(3) of the Standard Specifications, provided that the material
can be compacted in accordance with the requirements of Sections 2-03.3(14)C and 2-
03.3(14)D of the Standard Specifications. If wet-weather construction makes it difficult to
achieve the required moisture and compaction density, Select Borrow (Section 9-03.14(2)) or
Gravel Borrow (Section 9-03.14(1)) may be used in lieu of Common Borrow.
Temporary Excavation
Limited excavation may be required in order to construct the reinforced soil slope.
Temporary excavations sloped to 1:1 should perform adequately during construction.
If the Renton Formation bedrock is encountered in temporary excavations needed to place
reinforcing grids, the lengths of the geogrid may be reduced, provided the project
geotechnical engineer is notified in advance to verify subsurface conditions. In no case shall
the reduced length of reinforcing be keyed into the Renton Formation less than 5 feet.
Existing Utilities
No known utilities cross beneath the proposed the RSS footprint. If any are encountered
during construction, they should be brought to the attention of the project geotechnical
engineer. In no case should the arrangement of slope reinforcing by modified to
accommodate utilities without the approval of the project geotechnical engineer.
Drainage and Erosion Control
Temporary construction slopes shall direct water away from the RSS slope face to prevent
erosion. The face of the RSS shall be stabilized following project temporary erosion and
sediment control procedures and shall be planted with permanent vegetation in accordance
with the project landscaping plans.
References
AASHTO (2002). Standard Specifications for Highway Bridges, 17th Edition (2002) – Allowable
Stress Design. American Association of State Highway and Transportation Officials, 2002.
AASHTO (2007). AASHTO LRFD Bridge Design Specifications, Fourth Edition. American
Association of State Highway and Transportation Officials, 2007.
FHWA (2001). Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and
Construction Guidelines. U.S. Department of Transportation, Federal Highway
Administration. FHWA-NHI-00-043. March 2001.
RocScience (2008). SLIDE Version 5.0 - User’s Manual.
WSDOT (2008). Geotechnical Design Manual. Washington State Department of
Transportation.
WSDOT (2008). Standard Specifications for Road, Bridge, and Municipal Construction.
Washington State Department of Transportation. M41-10.
90100100
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130
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130
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140140140
150150
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5
0
160160160
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170
170
170 170
170 170
170180180
180
180
180180 190190
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19020
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200
200
200
200 200210
210
210
210 210210220
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220
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220230230230
230
230
230
240240240240
ROW CLF
CLF
200
NO.
Washington State
Department of Transportation
ISSUE DATE ISSUE RECORD - DESCRIPTION DESIGNED BY ENTERED BY CHECKED BY
WASH10
NO.
DESIGN
MANAGER:
DESIGN
TASK LEAD:
PACKAGE:
REGION STATE
CONTRACT NO.
P.E. STAMP BOX
DATE
B 07/29/09 K. LORENTSONFINAL DESIGN - 1B M. ROHILAC. HERMOGENES
08/14/09 K. LORENTSON M. ROHILAC. HERMOGENES0RELEASE FOR CONSTRUCTION - 1B WSDOT EXCHANGE PROPI-405
AND SR 515 INTERCHANGE
STAGE 2 - WIDENING
I-5 TO SR 169
SHEET
OF
SHEETS
7624_04_CG_1_01.dlv2:48:56 PM8/12/20097624150160
160
170170
170
180
180
180
190
190
190200
200
200210 210
220220
230
230230
1110
12 13 14 15 16
9
100101102103EE
R.J
NO
RTHBOUND
I-405
SOUTHBOUND I-405
J. BAUMAN
K. LORENTSON
SCALE IN FEET
0 30 60
A
T. 23N. R. 5E. W.M.
CG-0-02
CG-0-02
CEDAR RW LINE
A S. FORMAN
C. HERMOGENES
CEDAR AVE S
1230
1230
B
06/19/09 PRELIMINARY DESIGN
NB405 LINE
SB405 LINE
LEGEND
200
1.5:1CUT LINE
CG-0-01
NOTES:2:12:11.5:11.5:12:1FILL LINE1.5:12:1
1.5:1
2:1
1.5:12:1
1
.5
:1
2:11.5:12:1
1.5:1
CEDAR RW
10+91.62, 113.77’ RT
ELEV 228.00
CEDAR RW
11+63.35, 113.00’ RT
ELEV 230.00
CEDAR RW
12+86.86, 8.00’ LT
ELEV 232.00
CEDAR RW
11+89.62, 8.00’ LT
ELEV 230.00’
CEDAR RW
13+74.52, 114.82’ RT
ELEV 234.00
CEDAR RW
14+69.96, 115.25’ RT
ELEV 236.00
CEDAR RW
14+00.63, 8.00’ LT
ELEV 234.00
CEDAR RW
15+39.28, 118.95’ RT
ELEV 236.00
CEDAR RW
15+99.89, 0.00’ RT
ELEV 238.00
CEDAR RW
14+97.08, 8.00’ LT
ELEV 236.00
CONTOUR GRADING
WSDOT EXCHANGE PROPERTY2:1CEDAR RW
12+60.26, 113.59’ RT
ELEV 232.00
CEDAR RW
10+97.21, 10.78’ LT
ELEV 228.00’
N1^26’53.75"E
2:1
A. BASTASCH
DITCH, SEE DRAINAGE PLANS
VARIES
2:1 MAX
STREAM
BUFFER
THUNDER
HILLS CREEK
EXISTING MAJOR CONTOUR
EXISTING MINOR CONTOUR
PROPOSED MAJOR CONTOUR
PROPOSED MINOR CONTOUR
STREAM/ WETLAND BUFFER
SLOPE ARROW
LIMITED ACCESS
WSDOT ROW
AR
LI
NE
1.
2.
3.
4.
ACCESS
SEE CG-0-05
1.5:1
629 CEDAR AVE S
CONDOMINIUMS
FOR DITCH PROFILES, SEE DRAINAGE
PLAN AND PROFILES.
FOR SLOPE ROUNDING, SEE DLS-0-02.
FOR REINFORCED SOIL SLOPE DETAILS,
SEE SHEET CG-0-04.
FOR EXISTING UTILITIES,
SEE UTILITY PLANS.
RFC - 1B
E405
L
INE
LIMITS OF FILL WITHIN
WSDOT RIGHT-OF-WAY
NOT TO EXCEED
SIX (6) FEET IN HEIGHT
AND NOT TO ENCROACH
OVER FILL LINE SHOWN
Dense BrushTreesTreesTreesDense BrushBrushBrushBrushSSSSSSSSRandomSIGN Request 140780TR_SN_OverheadSignTR_SN_OverheadSignUTILITY Request 1TP_MM_UnknownObjectTP_MM_UnknownObjectRD_BR_BarrierFaceRD_BR_BarrierFace31379Copy of GEOTECH Request 1Random"EXIT 4""900 WEST""169 SOUTH"100100110110120120120130130130140140140
150150150160160160170170170180180180190190190200200200210210210220220220230230230240240240250250BL_LN_BreaklineGenericBL_LN_BreaklineGeneric1000Book 1BreaklineWSDOT EXCHANGE PROP!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>!>CEDAR AVENB I-405B-5B-3B-2B-1B-11B-10TP-8TP-7TP-6TP-5TP-4TP-3TP-2TP-1TP-16TP-15TP-14TP-13TP-12515-7-06515-6-06515-4-06SRX-20-05CDB-6p-08050 100 150 20025Feet³Figure 2: WSDOT Exchange PropertySubsurface Investigation Locations
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Attachment A: WSDOT Exchange Property RSS
Plans
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90100100
100
100100100
110110
110
110
110110
120120
120120120120
130
130 13
0
130
130
130
130140140140
140140140
150150
150
150
150
1
5
0
160160160
160
160
160
170
170
170 170
170 170
170180180
180
180
180180 190190
190
190
190
19020
0
200
200
200
200 200210
210
210
210 210210220
220
220
220
220
220230230230
230
230
230
240240240240
ROW CLF
CLF
200
NO.
Washington State
Department of Transportation
ISSUE DATE ISSUE RECORD - DESCRIPTION DESIGNED BY ENTERED BY CHECKED BY
WASH10
NO.
DESIGN
MANAGER:
DESIGN
TASK LEAD:
PACKAGE:
REGION STATE
CONTRACT NO.
P.E. STAMP BOX
DATE
B 07/29/09 FINAL DESIGN - 1B R. PLAYER K. LORENTSON C. HERMOGENES
0 08/14/09 R. PLAYER K. LORENTSON C. HERMOGENESRELEASED FOR CONSTRUCTION - 1B
I-405
AND SR 515 INTERCHANGE
STAGE 2 - WIDENING
I-5 TO SR 169
SHEET
OF
SHEETS
7624_04_CG_1_03.dlv2:27:41 PM8/10/20097624150160
160
170170
170
180
180
180
190
190
190200
200
200210 210
220220
230
230230
N7^21’10
.72"E
1110
12 13 14 15 16
9
100101102103PROFE
S
SIONAL ENGINEERREGISTEREDSTATE OF WA
S
HINGT
ON43006 OCH STEH N V
A
N PL
AR
P
RE
YE
NO
RTHBOUND
I-405
SOUTHBOUND I-405
J. BAUMAN
K. LORENTSON
SCALE IN FEET
0 30 60
T. 23N. R. 5E. W.M.
CEDAR RW LINE
CEDAR AVE S
1230
1230
06/24/09 PRELIMINARY DESIGN
NB405 LINE
SB405 LINE
CG-0-03
NOTES:
R. PLAYER J. THEODORE
R. PLAYER
REINFORCED SOIL SLOPE PLAN
CEDAR RW 15+95CEDAR RW 13+75
CEDAR RW 12+50
CEDAR RW 11+50
CEDAR RW 10+75
CEDAR RW 14+50 CEDAR RW 15+45
CEDAR RW 13+75
CEDAR RW 12+50CEDAR RW 11+75
CEDAR RW 10+75
CEDAR RW 11+75
LEGEND
200
1.5:1CUT LINE
FILL LINE2:12:11.5:11.5:1VARIES
2:1 MAX2:11.5:12
:1
1
.5
:1 2:1
1.5:1
A
CEDAR RW 13+00
L min = 45’
WSDOT EXCHANGE PROPERTY
CEDAR RW 14+50
CEDAR RW 15+45
2:1
FOR PRIMARY GEOGRID REINFORCING
ELEVATION TABLE, SEE SHEET CG-0-04.
FOR REINFORCED SOIL SLOPE DETAIL,
SEE SHEET CG-0-04.
FOR CONTOUR GRADING PLAN, SEE
SHEET CG-0-01.
1.
2.
3.2:11.5:1
2:1
2:1
CEDAR
RW 15+95
CEDAR RW 10+35
PRIMARY GEOGRID TOP
REINFORCING ELEVATION,
SEE NOTE 1
PRIMARY GEOGRID BOTTOM
REINFORCING ELEVATION
SEE NOTE 1
STREAM
BUFFER
CEDAR RW 10+35
AR
LI
NE
2:1
1.5:1
L min = 40’
L min = 40’L min = 50’L min = 25’
2:11.5:1
SLOPE ARROW
LIMITED ACCESS
WSDOT RIGHT OF WAY
STREAM WETLAND BUFFER
PROPOSED MINOR CONTOUR
PROPOSED MAJOR CONTOUR
EXISTING MINOR CONTOUR
EXISTING MAJOR CONTOUR
RFC - 1B
1.5:1
CEDAR RW 11+50
CEDAR RW 13+00
STREAM MITIGATION
AREA ACCESS,
SEE CG-0-05
E
405
L
INE
B FINAL DESIGN - 1B R. PLAYER K. LORENTSON07/29/09 C. HERMOGENES
R. PLAYER K. LORENTSON08/14/09 C. HERMOGENES0RELEASED FOR CONSTRUCTION - 1B
NO.
Washington State
Department of Transportation
ISSUE DATE ISSUE RECORD - DESCRIPTION DESIGNED BY ENTERED BY CHECKED BY
WASH10
NO.
DESIGN
MANAGER:
DESIGN
TASK LEAD:
PACKAGE:
REGION STATE
CONTRACT NO.
P.E. STAMP BOX
DATE
1
L
6’ MIN. (TYP)
VARIES
NOTES:
1’ MAX
(TYP)
1’ MAX
(TYP)
REINFORCED SOIL SLOPE DETAIL
2’ MAX
(TYP)
NTS
PRELIMINARY DESIGN
J. BAUMAN
K. LORENTSON
CG-0-04
A
06/24/09
REINFORCED SOIL SLOPE DETAIL
R. PLAYER J. THEODORE
R. PLAYER
WSDOT EXCHANGE PROPERTY
PRIMARY GEOGRID REINFORCING ELEVATION TABLE
1.5 MAX
MIN (SEE NOTES 1 & 4)
COMMON BORROW (TYP)
SEE TECHNICAL SPECIFICATIONS
PRIMARY GEOGRID (TYP)
SEE TECHNICAL SPECIFICATIONS
FINISHED GRADE,
SEE CONTOUR GRADING
PLAN ON SHEET CG-0-01
SECONDARY GEOGRID (TYP)
SEE TECHNICAL SPECIFICATIONS,
SEE NOTE 2
SEE ROADSIDE RESTORATION
PLANS FOR PLANTING DETAILS.
SEE SHEET ECD-0-15 FOR
EROSION CONTROL DETAILS
RFC - 1B
SECONDARY GEOGRID (TYP)
SEE NOTE 5
SEE PRIMARY GEOGRID REINFORCEMENT TABLE FOR MINIMUM LENGTH (L MIN) OF EMBEDMENT.
SECONDARY GEOGRID MINIMUM LENGTH OF EMBEDMENT = 6’.
LENGTH OF EMBEDMENT IS MEASURED HORIZONTAL FROM FACE OF SLOPE.
SLOPE TO BE BENCHED INTO EXISTING HILLSIDE IN ACCORDANCE WITH
STANDARD SPECIFICATION 2-03.3(14) "HILLSIDE TERRACES".
SECONDARY GEOGRID LAYERS SHALL CONTINUE TO TOP OF SLOPE ABOVE PRIMARY GEOGRID.
1.
2.
3.
4.
5.PROFE
S
SIONAL ENGINEERREGISTEREDSTATE OF WA
S
HINGT
ON43006 OCH STEH N V
A
N PL
AR
P
RE
YEI-405
AND SR 515 INTERCHANGE
STAGE 2 - WIDENING
I-5 TO SR 169
SHEET
OF
SHEETS
7624_04_CG_1_04.dlv1:50:34 PM8/10/20097624
REV 0
RTN/RS2_EXCHANGEPOPERTY_RSS_DESIGNRECOMMENDATIONS_REV0_081409.DOC
COPYRIGHT 2009 BY I-405 CORRIDOR DESIGN BUILDERS • COMPANY CONFIDENTIAL
Attachment B: WSDOT Exchange Property
Exploration Logs
REV 0
RTN/RS2_EXCHANGEPOPERTY_RSS_DESIGNRECOMMENDATIONS_REV0_081409.DOC
COPYRIGHT 2009 BY I-405 CORRIDOR DESIGN BUILDERS • COMPANY CONFIDENTIAL
C-17
C-18
C-19
C-20
SANDSTONE, light gray, coarse grained, highly weathered,
very weak rock. Discontinuities are moderately spaced and in
fair condition. Recovered:100% RQD:100 FF:0
Massive texture with moderately to closely spaced thin
interbeds of coal (10 degrees).
SANDSTONE, light gray, coarse grained, highly weathered,
very weak rock. Discontinuities are moderately spaced and in
fair condition. Recovered:100% RQD:100 FF:0
Massive texture
Thin coal beds (20 degrees) from 81.0' to 82.0'
SANDSTONE, light gray, coarse grained, highly weathered,
very weak rock. Discontinuities are moderately spaced and in
fair condition. Recovered:100% RQD:100 FF:0
Massive texture
Coal seam (35 degrees) at 84.0'
SANDSTONE, light gray, coarse grained, highly weathered,
very weak rock. Discontinuities are moderately spaced and in
fair condition. Recovered:100% RQD:100 FF:0
Massive texture
A standpipe monument was installed on this boring.
The implied accuracy of the borehole location
information displayed on this boring log is typically
sub-meter in (X,Y) when collected by the HQ Geotech
Division and sub-centimeter in (X,Y,Z) when collected by theDepth (ft)Sample TypeSample No.(Tube No.)LabTestsDescription of Material
GroundwaterInstrumentElevation (ft)Profile20 40 60 80
Moisture Content
Field SPT (N)
RQD
Blows/6"
(N)
RQD
FF
and/or
75
80
85
90
95
LOG OF TEST BORING
SR
I-405 Renton Stage 2
Job No.
Project
of 5
HOLE No.
Sheet
Driller
XL-2754
Henderson, Daniel
4
Start Card
Lic#
CDB-6p-08
R-72554
2742
405 Elevation
65
60
55
50
45
136.8 ft
Department of Transportation
Washington State
SOILA XL-2754 I-405 RENTON STAGE 2 PROJECT.GPJ SOIL.GDT 9/17/08
0
5
10
15
20
25
30
35
40
45
50
Soil/Rock Profile
Description
Graphic Log Depth in FeetApproximate Ground Surface Elevation: 200 feet Page 1 of 2
Boring Log - Figure 5
Comments
Groundwater
Observations
0
5
10
15
20
25
30
35
40
45
50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB BRB: 04/29/09Rock
Rock
Rock
Rock
Rock
SM
Forest duff and topsoil
Rock
Bedrock encountered at
5 feet
Brown silty fine to medium SAND (completely weathered
bedrock)
Brown medium-grained SANDSTONE (slightly weathered,
very weak) (Renton Formation bedrock)
Light gray medium-grained SANDSTONE (fresh, very weak) (Renton Formation bedrock)
Light brown medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Dark brown CARBONACEOUS SHALE (fresh, very weak)
(Renton Formation bedrock)
Light gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Rock
Rock
Rock
Boring B-5
50
55
60
65
70
75
80
85
90
95
100
Soil/Rock Profile
Description
Graphic Log Depth in FeetBoring B-5
Page 2 of 2
Comments
50
55
60
65
70
75
80
85
90
95
100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 5
Groundwater
Observations
Icicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB BRB:04/29/09Boring completed at 71 feet on April 27, 2009
RockLight gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Dark brown CARBONACEOUS SHALE (fresh, very weak)
(Renton Formation bedrock)
Black COAL (fresh, very weak) (Renton Formation
bedrock)
Light gray medium-grained SANDSTONE (fresh, very weak) (Renton Formation bedrock)
NO. 3 COAL SEAM
(coal seam intact from
57 - 70 feet - not mined)
Rock
Rock
Rock
Rock
No groundwater observed
0
5
10
15
20
25
30
35
40
45
50
Soil/Rock Profile
Description
Graphic Log Depth in FeetBoring B-10
Approximate Ground Surface Elevation: 186 feet Page 1 of 2
Boring Log - Figure 10
Comments
Groundwater
Observations
0
5
10
15
20
25
30
35
40
45
50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB JMS: 04/30/09Rock
Rock
Rock
Rock
Rock
Forest duff and topsoil
Rock
Bedrock encountered at
5 feet
Brown silty fine to medium SAND (completely weathered
bedrock)
Light gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Rock
Rock
Rock
SM
Dark brown CARBONACEOUS SHALE (fresh, very weak)
(Renton Formation bedrock)
Black COAL (fresh, very weak) (Renton Formation
bedrock)
NO. 3 COAL SEAM
(coal seam intact from
36 - 49 feet - not mined)
Light gray medium-grained SANDSTONE (fresh, very weak)
(Renton Formation bedrock)Rock
50
55
60
65
70
75
80
85
90
95
100
Soil/Rock Profile
Description
Graphic Log Depth in FeetBoring B-10
Page 2 of 2
Comments
50
55
60
65
70
75
80
85
90
95
100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 10
Groundwater
Observations
Icicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB JMS:04/30/09Boring completed at 59 feet on April 27, 2009
RockLight gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Rock
No groundwater observed
0
5
10
15
20
25
30
35
40
45
50
Soil/Rock Profile
Description
Graphic Log Depth in FeetBoring B-11
Approximate Ground Surface Elevation: 185 feet Page 1 of 2
Boring Log - Figure 11
Comments
Groundwater
Observations
0
5
10
15
20
25
30
35
40
45
50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB JMS: 04/30/09Rock
Rock
Rock
Rock
Rock
Forest duff and topsoil
Rock
Bedrock encountered at
5 feet
Brown silty fine to medium SAND (completely weathered
bedrock)
Light gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Rock
Rock
Rock
SM
Dark brown CARBONACEOUS SHALE (fresh, very weak)
(Renton Formation bedrock)
Black COAL (fresh, very weak) (Renton Formation
bedrock)
NO. 3 COAL SEAM
(coal seam intact from
41 - 52 feet - not mined)
50
55
60
65
70
75
80
85
90
95
100
Soil/Rock Profile
Description
Graphic Log Depth in FeetBoring B-11
Page 2 of 2
Comments
50
55
60
65
70
75
80
85
90
95
100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 11
Ground Water
Observations
Icicle Creek Engineers
See Figure 4 for explanation of symbols ICE Project No. 0864-001Project Name: I-405 PropertyLogged by: BRB JMS:04/30/09Boring completed at 59 feet on April 27, 2009
Rock
Light gray medium-grained SANDSTONE (fresh, very
weak) (Renton Formation bedrock)
Rock
Black COAL (fresh, very weak) (Renton Formation
bedrock)
NO. 3 COAL SEAM
(coal seam intact from
41 - 52 feet - not mined)
No groundwater observed
REV 0
RTN/RS2_EXCHANGEPOPERTY_RSS_DESIGNRECOMMENDATIONS_REV0_081409.DOC
COPYRIGHT 2009 BY I-405 CORRIDOR DESIGN BUILDERS • COMPANY CONFIDENTIAL
Attachment C: Reinforced Soil Slope Technical
Specifications
(******) 1
6-19 REINFORCED SOIL SLOPES, I.5:1 (HORIZONTAL TO VERTICAL) SLOPES 2
REVISION A – NEW SECTION 3
6-19.1 Description 4
6-19.1(1) Geosynthetic Reinforced Slope 5
A. This item of work shall consist of furnishing and constructing geosynthetic 6
reinforced soil slopes in accordance with the details shown in the Plans, the 7
Standard Specifications, and Special Provisions. 8
B. These Special Provisions apply only to 1.5:1(horizontal to vertical) Reinforced Soil 9
Slopes (RSS). 10
C. The word “geosynthetic” used in this Special Provision refers to polyester and 11
polyolefins geogrids only. Polyolefins include HDPE and polypropylene. 12
6-19.2 Materials 13
Section 6-19.2 is supplemented with the following: 14
(******) 15
Geosynthetic Material Requirements 9-33.1(1) 16
6-19.2(1) Borrow for Geosynthetic Reinforced Slopes 17
A. Except for the first 6 inches (minimum) to 12 inches (maximum) from the slope 18
face, all backfill material used in the reinforced soil zone of the geosynthetic 19
reinforced slope shall be free from organic or otherwise deleterious material and 20
shall conform to the gradation for Section 9-03.14(3) Common Borrow, as modified 21
as follows: 22
Sieve Size Percent Passing 23
3.0 inch 100 24
No. 4 100 - 20 25
No. 200 0 - 35 26
The material shall be non-plastic and substantially free of shale or other soft, poor 27
durability particles, and shall not contain recycled materials, such as glass, 28
shredded tires, portland cement concrete rubble, or asphaltic concrete rubble. The 29
backfill material shall meet the following requirements: 30
Property Test Method Allowable 31
Test Value 32
pH AASHTO T 289-91 3 to 9 33
Reinforced slope backfill material satisfying these gradation and chemical 34
requirements shall be classified as nonaggressive. 35
6-19.2(2) Geotextile Properties 36
Geogrid reinforcement (primary and secondary) in geosynthetic reinforced slopes 37
shall conform to the following properties: 38
Table 11: Long-term tensile strength, Tal, required for geosynthetic reinforcement 39
used in geosynthetic reinforced slopes. 40
Slope
Vertical
Spacing of
Primary
Reinforcement
Primary
Reinforcement
Layer
Distance from
Top of
1,2Minimum
Long-Term
Tensile
Strength, Tal,
for Primary
1Minimum
Ultimate
Tensile
Strength
(ASTM D6637)
Location Layers Reinforced
slope
Reinforcement for Secondary
Reinforcement
Defoor
Property
2 feet Varies, see
drawings
1,250 lbs/ft. 115 lbs/in.
1These long-term tensile strength requirements apply only in the geosynthetic 1
direction perpendicular to the slope face. 2
2Tal shall be determined in accordance with WSDOT Test Method 925. 3
6-19.2(3) Source Approval 4
A. Geosynthetic products which are qualified for use in geosynthetic reinforced 5
structures for primary reinforcement (Classes 1, 2, or both) are listed in the current 6
Qualified Products List (QPL). 7
For geosynthetic products proposed for use as primary reinforcement which are not 8
listed in the current QPL, the Design-Builder shall submit test information and the 9
calculations used in the determination of Tal performed in accordance with WSDOT 10
Test Method 925 to the WSDOT Headquarters Materials Laboratory in Tumwater for 11
evaluation. WSDOT will require up to 30 calendar days after receipt of the 12
information to complete the evaluation. 13
Source approval for reinforced slope primary reinforcement geosynthetic materials 14
listed in the current QPL, or as approved based on data developed and submitted in 15
accordance with WSDOT Test Method 925, will be based on conformance to the 16
applicable values in Section 6-19.2(2) of this Technical Specifications. 17
B. The Design-Builder shall submit to the Design-Build Engineer the following 18
information regarding the geosynthetic secondary reinforcement product(s) 19
proposed for use: 20
Manufacturer's name and current address, 21
Full product name, 22
Geosynthetic structure, including fiber/yarn type, and 23
Geosynthetic polymer type(s). 24
If the geosynthetic source has not been previously evaluated or included in the QPL, 25
a sample of each proposed geosynthetic shall be submitted to the WSDOT 26
Headquarters Materials Laboratory in Tumwater for evaluation. A maximum of 14 27
calendar days will be required for this testing once the samples and required product 28
information arrive at the Materials Laboratory. Source approval will be based on 29
conformance to the applicable values in Table 11. Source approval will not be the 30
basis of acceptance of specific lots of material unless the lot sampled can be clearly 31
identified, and the number of samples tested and approved meet the requirements 32
of WSDOT Test Method 914. 33
6-19.2(4) Acceptance 34
A. The Design-Builder shall follow the acceptance sample specifications in Section 9-35
33.4(3) of the Standard Specifications. 36
6-19.3 Construction Requirements 1
6-19.3(1) Submittals 2
A. The Design-Builder shall submit to the Design-Build Engineer, a minimum of 14 3
calendar days prior to beginning construction of each reinforced slope, detailed 4
plans for each reinforced slope and as a minimum, the submittals shall include the 5
following: 6
1. The Design-Builder’s proposed reinforced slope construction method, 7
including any proposed forming systems, types of equipment to be used 8
and proposed erection sequence. 9
2. Manufacturer’s Certificate of Compliance, samples of the reinforced slope 10
geosynthetic(s) and sewn-seams for the purpose of acceptance as 11
specified. 12
3. Details of terminating a top layer of reinforced slope geosynthetic and 13
backfill due to a changing reinforced slope profile. 14
Approval of the Design-Builder’s proposed reinforced slope construction details and 15
methods shall not relieve the Design-Builder of their responsibility to construct the 16
reinforced slopes in accordance with the requirements of these Specifications. 17
6-19.3(2) Examination 18
A. The Design-Builder shall check the geogrid upon delivery to verify that the proper 19
material has been received. Information regarding manufacturer, product, and lot 20
number shall be recorded. The geogrid shall be inspected by the Design-Builder to 21
confirm that the geogrid is free of flaws or damage occurring during manufacturing, 22
shipping, or handling. 23
6-19.3(3) Preparation 24
A. The Design-Builder shall excavate for the reinforced slope in accordance with 25
Section 2-09.3(4) of the Standard Specifications, and conforming to the limits shown 26
in the Plans. The subgrade soil shall be excavated to the lines and grades as 27
shown on the Plans and as outlined in the Standard Specifications, or as directed by 28
the Design-Build geotechnical Engineer. Before placement of fill or backfill for the 29
RSS, all surface vegetation, topsoil, trash, construction debris, or other deleterious 30
materials shall be removed from beneath the reinforced soil zone and properly 31
disposed of offsite. Loose, soft, or excessively wet material shall also be removed 32
and replaced with competent backfill in accordance with Section 2-09.3(1)C. 33
Subgrade shall be leveled as required for slope construction and compacted in 34
accordance with the requirements of Sections 2-03.3(14)C and 2-03.3(14)D of the 35
Standard Specifications. 36
B. The project Design-Build geotechnical Engineer shall inspect the prepared subgrade 37
prior to placement of geosynthetic reinforcing or backfill. Overexcavation and 38
removal of unsuitable subgrade materials shall be as directed by the project 39
geotechnical Design-Build Engineer. 40
C. The Design-Builder shall direct all surface runoff from adjacent areas away from the 41
reinforced slope construction site. 42
6-19.3(4) Installation 43
A. The Design-Builder shall begin reinforced slope construction at the lowest portion of 44
the excavation and shall place each layer horizontally as shown in the Plans. The 45
Design-Builder shall complete each layer entirely before beginning the next layer. 46
B. The Design-Builder shall use a temporary form or bracing system (if needed) to 1
minimize sagging of the geosynthetic facing elements during construction. Primary 2
and secondary geogrids shall be placed in accordance with Manufacturer’s 3
recommendations and the drawings and specifications. 4
C. Geogrid shall be laid at the proper elevation and orientation as shown on the Plans 5
or as directed by the Design-Build Engineer. Primary geogrid shall be placed such 6
that the machine direction (longitudinal axis) of the geogrid is perpendicular to the 7
face of the slope. 8
D. Correct orientation (roll direction) of the geogrid shall be verified by the Design-9
Builder. The Design-Builder shall stretch out the geosynthetic in the direction 10
perpendicular to the slope face to ensure that no slack or wrinkles exist in the 11
geosynthetic prior to backfilling. Geogrid may be temporarily secured in place with 12
staples, pins, sand bags, or backfill as required by fill properties, fill placement 13
procedures, or weather conditions, or as directed by the Design-Build Engineer. 14
E. Geogrid splices shall consist of adjacent geogrid strips butted together and fastened 15
using hog rings, or other methods approved by the Design-Build Engineer, in such a 16
manner to prevent the splices from separating during geogrid installation and 17
backfilling. The Design-Builder shall offset geosynthetic splices in one layer from 18
those in the other layers such that the splices shall not line up vertically. Geogrids 19
manufactured using polyolefins (e.g., HDPE and PP) shall be connected with a 20
mechanical polymer bar. Geogrids manufactured of polyester shall be connected by 21
sewing with Kevlar sewing thread perpendicular to the direction of loading at the 22
ends of the materials. Splices parallel to the slope face will not be allowed, as 23
shown in the Plans. 24
F. Primary reinforcing geosynthetic shall be cut to the length shown in the Plans. For 25
geogrids, the end of the primary reinforcing located at the face of the slope shall be 26
cut so that the cut ribs extend no more than 0.6 inch but not less than 0.2 inch from 27
the cross ribs. For geogrids, the length of the reinforcement required as shown in 28
the Plans shall be defined as the distance between the geosynthetic facing and the 29
last geogrid node at the end of the reinforcement in the slope backfill. 30
G. Geosynthetic reinforcement splices exposed at the slope face shall prevent loss of 31
backfill material through the face. The splicing material exposed at the slope face 32
shall be as durable and strong as the material to which the splices are tied. 33
H. Place only that amount of geogrid that can be covered with backfill within the same 34
day to prevent undue damage to the geogrid. 35
6-19.3(5) Fill Placement over Geogrid 36
A. The Design-Builder shall place and compact the reinforced slope backfill in 37
accordance with the reinforced slope construction sequence detailed in the Plans 38
and Method C of Section 2-03.3(14)C, except as follows: 39
1. The minimum compacted backfill lift thickness of the first lift above each 40
geosynthetic layer shall be 6 inches. 41
2. The maximum lift thickness after compaction shall not exceed 12 inches. 42
3. The Design-Builder shall decrease this lift thickness, if necessary, to obtain 43
the specified density. 44
4. Rollers shall have sufficient capacity to achieve compaction without causing 1
distortion to the face of the wall in accordance with Section 6-19.3(7) of this 2
Technical Specification. 3
5. The Design-Builder shall not use sheepsfoot rollers or rollers with 4
protrusions. 5
6. Backfill shall be placed, spread, and compacted in such a manner that 6
minimizes the development of wrinkles and/or movement of the geogrid. 7
7. Design-Builder shall use whatever means are necessary to compact backfill 8
in all locations, including the outside edge of the embankment. The Design-9
Builder shall compact the zone within 3 feet of the slope face without causing 10
damage or distortion to the slope face or reinforcing layers by using light 11
mechanical tampers approved by the Design-Build Engineer. Overbuilding, 12
then cutting back the fill may be necessary but shall be done in a manner 13
that does not damage geogrid at the face. 14
B. Tracked construction equipment shall not be operated directly on the geogrid. The 15
Design-Builder shall place fill material on the geogrid in lifts such that 6 inches 16
minimum of fill material are between the vehicle or equipment tires or tracks and the 17
geogrid at all times. The Design-Builder shall remove all particles within the backfill 18
material greater than 3.0 inches in size. Turning of vehicles on the first lift above the 19
geosynthetic will not be permitted. The Design-Builder shall not dump fill material 20
directly on the geosynthetic without prior approval of the Design-Build Engineer. 21
C. Fill Placed outside of the reinforced backfill zone shall be placed and compacted in 22
accordance with Section 2-03(14)C Method C 23
6-19.3(6) Repair 24
A. Should the geogrid be damaged or the splices disturbed, the backfill around the 25
damaged or displaced area shall be removed and the damaged strip of geogrid 26
replaced by the Design-Builder. 27
B. Coated geogrids shall not be used if the coating is torn, shredded, cracked, 28
punctured, flawed, or cut, unless a repair procedure is carried out as approved by 29
the Design-Build Engineer. The repair procedure shall include placing a suitable 30
patch over the defective area or applying a coating solution identical to the original 31
coating. 32
6-19.3(7) Tolerances 33
A. The Design-Builder shall complete the base of the reinforced slope excavation to 34
within plus or minus 3 inches of the staked elevations unless otherwise directed by 35
the Design-Build Engineer. The Design-Builder shall place the external slope 36
dimensions to within plus or minus 2 inches of that staked on the ground. The 37
Design-Builder shall space the reinforcement layers vertically to within plus or minus 38
1 inch of that shown in the Plans. 39
B. The completed reinforced slope(s) shall meet the following tolerances: 40
Tolerance 41
Deviation from the design slope and 5 inches 42
horizontal alignment for the slope face, 43
when measured along a 10-foot straight 44
edge at the midpoint of each reinforced 45
slope layer, shall not exceed: 46
Deviation from the overall design slope 3 inches 1
per 10 feet of reinforced slope height shall 2
not exceed: 3
6-19.3(8) Protection 4
A. Follow the Manufacturer’s recommendations regarding protection from exposure to 5
sunlight. 6
7