USACE / NAVFAC / AFCESA / NASA UFGS-35 42 34 (January 2008)
----------------------------
Preparing Activity: USACE (CW) Superseding
UFGS-35 42 34 (April 2006)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 35 42 34
REINFORCED SOIL SLOPE
01/08
NOTE: This guide specification covers the requirements for steepened soil slopes
using geosynthetic soil reinforcement.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
NOTE: This guide specification does not address requirements for dewatering,
shoring, or earthwork below foundation level. Geometric requirements such as
slope height, crest, toe, length, and construction limits should be shown on
the drawings.
Notes before paragraphs are provided to present assumptions in preparation of
the guide specification, make suggestions for conditions that warrant revisions,
and provide background technical information or references for further information.
They should be consulted prior to revising wording for project specifications.
1.1 MEASUREMENT AND PAYMENT
1.1.1 Excavation
The unit of measurement for excavation will be the cubic meter (CM) yard (CY), computed by the average end area
method from cross sections taken before and after the excavation operations. The volume to be paid for will
be the material measured in its original position and removed from the excavation areas when the material is
acceptably utilized or disposed of as herein specified. The excavation shall be unclassified and include material
of all types. The measurement will not include material excavated without authorization. Payment will be made
at the respective unit price listed on the bidding schedule. Payment will be full compensation for furnishing
all material, labor, equipment, supplies and incidentals to complete the work. Shoring shall be incidental to
excavation.
1.1.2 Fill
Materials of all types not otherwise paid for shall be included under the unit price for fill. The unit of measurement
for fill will be the cubic meter (CM) yard (CY) computed by the average end area method from cross sections taken
of the final slope and after the excavation operations. The volume to be paid for will be the material measured
in its final position and placed within the designated areas when the material is acceptably placed and compacted
as herein specified. Payment will be made at the respective unit price listed on the bidding schedule. Payment
will be full compensation for furnishing all material, labor, equipment, supplies and incidentals to complete
the work.
1.1.3 Soil Slope Reinforcement
The unit of measurement for reinforcement will be the square meter (SM) yard (SY). The pay lines of the reinforcement
will be neat lines taken off the approved shop drawings. Overlaps for splicing (if allowed) and for the Contractors
convenience will not be measured for payment. Overlaps in curved sections will be measured assuming the slope
is linear. Payment will be made at the respective unit price listed on the bidding schedule. Payment will be
full compensation for furnishing all material, labor, equipment, supplies and incidentals to complete the work.
1.1.4 Soil Slope Drainage System
The drainage system, including associated pipe, geotextile, and aggregate will not be measured for payment and
will be paid for on a job basis (JB), complete. Payment will be full compensation for furnishing all material,
labor, equipment, supplies and incidentals to complete the work.
1.1.5 Soil Slope Facing and Seeding
Facing and seeding of the soil slope will be measured by the square meter (SM) yard (SY) of exposed face, measured
in the plane of the slope face. The pay lines will be neat lines taken off the approved shop drawings. The
work shall include [seed, mulch, turf reinforcement mat, erosion control blankets, erosion control netting, and
staples]. Payment will be made at the respective unit price listed on the bidding schedule, and will be full
compensation for furnishing all material, labor, equipment, supplies and incidentals to complete the work.
1.2 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO)AASHTO M 252(2008) Corrugated Polyethylene Drainage PipeAASHTO M 288(2006) Standard Specification for Geotextile Specification for Highway Applications][ASTM INTERNATIONAL (ASTM)ASTM C 136(2006) Standard Test Method for Sieve Analysis of Fine and Coarse AggregatesASTM D 1556(2007) Density and Unit Weight of Soil in Place by the Sand-Cone MethodASTM D 2487(2006e1) Soils for Engineering Purposes (Unified Soil Classification System)ASTM D 2488(2006) Description and Identification of Soils (Visual-Manual Procedure)ASTM D 4355(2007) Deterioration of Geotextiles from Exposure to Light, Moisture and Heat in a Xenon-Arc Type ApparatusASTM D 448(2008) Sizes of Aggregate for Road and Bridge ConstructionASTM D 4491(1999a; R 2004e1) Water Permeability of Geotextiles by PermittivityASTM D 4595(2005) Tensile Properties of Geotextiles by the Wide-Width Strip MethodASTM D 4632(2008) Grab Breaking Load and Elongation of GeotextilesASTM D 4751(2004) Determining Apparent Opening Size of a GeotextileASTM D 4873(2002) Identification, Storage, and Handling of Geosynthetic Rolls and SamplesASTM D 5035(2006; R 2008e1) Breaking Force and Elongation of Textile Fabrics (Strip Method)ASTM D 5199(2001; R 2006) Measuring Nominal Thickness of GeosyntheticsASTM D 5261(1992; R 2003) Measuring Mass Per Unit Area of GeotextilesASTM D 5321(2008) Determining the Coefficient of Soil and Geosynthetic or Geosynthetic and Geosynthetic Friction by the Direct Shear MethodASTM D 6637(2001) Standard Test Method for Determining Tensile Properties of Geogrids by the Single or Multi-Rib Tensile MethodASTM D 6706(2001; R 2007) Standard Test Method for Measuring Geosynthetic Pullout Resistance in SoilASTM D 6938(2007a) Standard Test Method for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)ASTM D 698(2007e1) Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/cu. ft. (600 kN-m/cu. m.))][GEOSYNTHETIC INSTITUTE (GSI)GSI GRI GG6(1996) Grip Types for Use in Wide Width Testing of Geotextiles and GeogridsGSI GRI GT6(1992) Geotextile Pullout][NATIONAL CONCRETE MASONRY ASSOCIATION (NCMA)NCMA TR127(1997) Design Manual for Segmental Retaining Walls][U.S. ARMY CORPS OF ENGINEERS (USACE)EM 385-1-1(2008) Safety and Health Requirements Manual][U.S. DEPARTMENT OF AGRICULTURE (USDA)AMS Seed Act(1940; R 1988; R 1998) Federal Seed Act][U.S. FEDERAL HIGHWAY ADMINISTRATION (FHWA)FHWA SA-96-071(2001) Mechanically Stabilized Earth Walls and Reinforced Soil Slopes: Design and Construction Guidelines]1.3 DEFINITIONS
NOTE: Subparagraph "Reinforcement" - This guide specification only applies
to geosynthetic (extensible) reinforcement. There are differences in design
and construction applicable to steel soil (inextensible) reinforcement.
1.3.1 Drainage Aggregate
Granular soil or aggregate which is placed in or around drains.
1.3.2 Fill
Soil or aggregate placed in, behind, or below the embankment or slope will be referred to as fill.
1.3.3 Reinforced Fill
Soil which is placed and compacted within the neat line volume of reinforcement as outlined on the plans.
1.3.4 Retained Fill
Soil which is placed and compacted behind the reinforced fill
1.3.5 Reinforcement
Reinforcement consisting of a geogrid or a geotextile product manufactured for use as reinforcing. Reinforcement
does not include steel products.
1.3.6 Long Term Design Strength
The long term design strength (LTDS) is:
LTDS = Tult / (RFD * RFID * RFCR)
where:
Tult is the ultimate strength
RFD is the reduction factor for chemical and biological durability
RFID is the reduction factor for installation damage
RFCR is the reduction factor for creep
1.4 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] The following shall be
submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Detailed Drawings[; G][; G, [_____]].
The fabrication and installation drawings, as specified.
Shoring
Plans and design computations for all shoring used [at least 30 days prior to installation].
SD-03 Product Data
Geotextile Reinforcement
Descriptive technical data on the reinforcement and geotextile filter materials. Include
all material properties specified under paragraph PRODUCTS.
Field Testing Results
Testing data specific to the reinforcement to be supplied.
a. The coefficient for direct shear of the reinforcement on a soil similar in gradation and
texture to the material that will be used for fill in the reinforced zone shall be established
in accordance with ASTM D 5321.
b. The coefficient of interaction for pull-out resistance of the reinforcement in a soil similar
in gradation and texture to the material that will be used for fill in the reinforced zone shall
be established in accordance with ASTM D 6706 or GSI GRI GT6.
Calculations[; G][; G, [_____]].
Calcualtions of the long term design strength for the reinforcement, as specified.
SD-04 Samples
Reinforcement
NOTE: The geogrid sample is intended to be for visual demonstration prior to
product delivery. Quality assurance testing, if performed, should be obtained
from material actually delivered to the job. If testing is to be performed
for pre qualification, the minimum sample size should be 1 meter (36 inches)
in length and the full roll width. Although 1 square meter (yard) will provide
enough material for testing, the full roll width should be sampled since it
provides a better selection of specimen locations, it clearly shows the machine
and cross directions, and the difference in waste and shipping costs is negligible.
Samples of each type of reinforcement. The samples shall be labeled and have a minimum size
200 by 250 mm 8 by 10 inches. Geogrid shall include at least 2 apertures in each direction.
SD-07 Certificates
Certificates of Compliance
An affidavit certifying that the reinforcement meets the project specifications. The affidavit
shall be signed by an official authorized to certify on behalf of the manufacturer and shall
be accompanied by a mill certificate that verifies physical properties were tested during manufacturing
and lists the manufacturer's quality control testing. [If the affidavit is dated after award
of the contract and/or is not specific to the project, the supplier shall attach a statement
certifying that the affidavit addressed to the wholesale company is representative of the material
supplied.] The documents shall include a statement confirming that all purchased resin used
to produce reinforcement is virgin resin. The mill certificate shall include the tensile strength
tested in accordance with either ASTM D 4595 or ASTM D 6637.
1.5 QUALITY ASSURANCE
1.5.1 Manufacturer Representative
Provide a qualified and experienced representative from the reinforcement manufacturer available on an as-needed
basis during the construction. The representative shall visit the site for consultation [at least once during
construction] [as requested by the Contracting Officer].
1.5.2 Detailed Drawings
Submit Shop Drawings indicating fabrication and erection details for the slope, including sequencing and construction
procedures. If approved by the Contracting Officer, shop drawings may consist of marked up contract drawings
showing exact dimensions for the reinforcement supplied, and other minor revisions. The design and layout of
the internal reinforcement shall be subject to the following:
a. All features indicated in the contract documents shall be incorporated in the final design
and construction.
b. Each reinforcement level shall run as continuous as practical throughout the profile. If
a geotextile filter is present, the reinforcement shall be laid out so that interference with
the geotextile is minimized.
c. Any reinforcement not placed with the machine direction as the design reinforcement direction
shall be identified on the shop drawings.
1.5.3 Classification of soil materials
Classification of soil materials shall be performed by the Contractor in accordance with ASTM D 2488. The Contracting
Officer reserves the right to revise the Contractor classifications. In the case of disagreement, the Contracting
Officer's classification will govern unless the soils are classified in accordance with ASTM D 2487. All testing
completed by the Contractor in conjunction with soil material classification will be considered incidental to
the contract work.
1.6 DELIVERY, STORAGE, AND HANDLING
Check products upon delivery to assure that the proper material has been received and is undamaged. Protect
the materials from damage and exposure following the guidelines presented in ASTM D 4873.
1.6.1 Labeling
Label each roll with the manufacturer's name, product identification, roll dimensions, lot number, and date manufactured.
1.6.2 Handling
Geosynthetic rolls shall be handled and unloaded by hand, or with load carrying straps, a fork lift with a stinger
bar, or an axial bar assembly. Geosynthetic rolls shall not be dragged, lifted by one end, lifted by cables
or chains, or dropped to the ground.
1.6.3 Storage
Protect geosynthetics from cement, paint, excessive mud, chemicals, sparks and flames, temperatures in excess
of 70 degrees C 160 degrees F, and any other environmental condition that may degrade the physical properties.
If stored outdoors, elevate the rolls from the ground surface. Protect geosynthetics, except for extruded grids,
with an opaque waterproof cover. Deliver geosynthetics to the site in a dry and undamaged condition. Geotextiles
shall not be exposed to direct sunlight for more than 7 days.
PART 2 PRODUCTS
2.1 REINFORCEMENT
NOTES: Polyester is susceptible to hydrolysis in alkaline conditions. A high
molecular weight and low carboxyl end group number limit the hydrolysis. Normally,
a mill certificate or certification of these properties is adequate. The molecular
weight of polyester geosynthetics is determined from GSI GRI GG6, "Determination
of the Number Average Molecular Weight of Polyethylene Terephthalate (PET) yarns
Based on a Relative Viscosity Value", and ASTM D 4603, "Determining Inherent
Viscosity of Poly(Ethylene Terephthalate) (PET) by Glass Capillary Viscometer."
The carboxyl end group number is determined from GSI GRI GG7, "Carboxyl End
Group Content of Polyethylene Terephthalate (PET) Yarns."
Survivability - The AASHTO M 288 requirements are minimum requirements and
will not normally control in the product selection. The AASHTO reference can
be avoided by listing the grab, tear, burst, and puncture strengths. These
properties are listed in AASHTO M 288. The puncture strength (ASTM D 4833),
the trapezoidal tear strength (ASTM D4533) and the mullen burst strength (ASTM
D3786) are recognized as important geotextile properties. For the intended
application, the commonly specified values for puncture, burst and tear seldom
control the product selection.
Geosynthetic Selection - The Federal Acquisition Regulations require full and
open competition. Usually justification is not necessary if 3 products meet
the specifications. In combining various material requirements, it is easy
to specify a geosynthetic product that does not exist. Design utilizing geosynthetics
should include a listing with the calculations that verify the specified products
are commercially available. The Geosynthetics Fabrics Report magazine publishes
an annual specifiers guide that is ideal for this purpose.
Submit Certificates of Compliance for the materials as specified in the Submittals paragraph; and calculations
of the long term design strength for the reinforcement in accordance with the NCMA TR127 or FHWA SA-96-071.
The ultimate strength or index strength shall be based on the minimum average roll value tensile strength of
the product using the wide width strength test in ASTM D 4595 or the single rib test in ASTM D 6637. The calculation
shall itemize each reduction factor and include backup data to justify each reduction factor. Demonstrate splice
efficiency from testing, if used.
2.1.1 Geogrid Reinforcement
Provide geogrid which is a geosynthetic manufactured for reinforcement applications. The geogrid shall be a
regular network of integrally connected polymer tensile elements with aperture geometry sufficient to permit
significant mechanical interlock with the surrounding soil, aggregate, or other fill materials. The geogrid
structure shall be dimensionally stable and able to retain its geometry under manufacture, transport and installation.
The geogrid shall be manufactured with 100 percent virgin resin consisting of polyethylene, polypropylene, or
polyester, and with a maximum of 5 percent in-plant regrind material. Polyester resin shall have a minimum molecular
weight of 25,000 and a carboxyl end group number less than 30. Polyethylene and polypropylene shall be stabilized
with long term antioxidants.
2.1.2 Geotextile Reinforcement
Geotextile shall be a pervious sheet of polymeric material and shall consist of long-chain synthetic polymers
composed of at least 95 percent by weight polyethylene, polypropylene, or polyesters. The geotextile shall be
manufactured with 100 percent virgin resin, and with a maximum of 5 percent in-plant regrind material. Geotextile
shall be formed into a network such that the filaments or yarns retain dimensional stability relative to each
other, including the selvages. Polyester resin shall have a minimum molecular weight of 20,000 and a carboxyl
end group number less than 50. Polyethylene and polypropylene shall be stabilized with long term antioxidants.
For survivability during installation, and in addition to installation damage used in calculating the long term
design strength, the geotextile shall meet the minimum requirements in AASHTO M 288 Class 1, and shall have a
minimum mass per unit area of 270 g/m2 8 oz/sy.
2.1.3 Reinforcement Properties
NOTES: Permittivity - Reinforcement geotextiles should not puddle or impede
infiltration or seepage. AASHTO M 288 provides some default guidance.
2.1.3.1 Primary Reinforcement Properties
The reinforcement shown on the contract drawings shall meet the property requirements listed in Table 1. Reinforcement
strength requirements represent minimum average roll values in the machine direction.
TABLE 1
PROPERTY REQUIREMENT TEST DESIGNATION
Long Term Design [_____] kN/m lb/inch NCMA TR127,
Strength Method A
Permittivity [0.5] per second ASTM D 4491
UV Resistance 70 percent after ASTM D 4355
500 hours
Coefficient of Interaction
for Pullout [.85] ASTM D 6706 or
GSI GRI GT6
Coefficient for Direct [_____] ASTM D 5321
Shear
2.1.3.2 Secondary Reinforcement Properties
The reinforcement shown on the contract drawings shall meet the property requirements listed in Table 2. Reinforcement
strength requirements represent minimum average roll values in the machine direction.
TABLE 2
PROPERTY REQUIREMENT TEST DESIGNATION
Long Term Design [_____] kN/m lb/inch NCMA TR127,
Strength Method A
Permittivity [0.5] per second ASTM D 4491
UV Resistance 70 percent after ASTM D 4355
500 hours
Coefficient of Interaction
for Pullout [.85] ASTM D 6706 or
GSI GRI GT6
Coefficient for Direct [_____] ASTM D 5321
Shear
2.1.3.3 Long Term Design Strength
Base the long term design strength on reduction factors for installation damage and durability that are applicable
to the fill that will be used. Minimum reduction factors for durability include: 1.1 for polyethylene and polypropylene
geosynthetics, 1.15 for coated polyester geogrids, and 1.6 for polyester geotextiles.
2.1.4 Reinforcement Splices
Splices in reinforcement shall consist of a standard method or device recommended and approved by the manufacturer
of the reinforcing. Splices shall be not less than 90 percent efficient (width wide tensile strength of splice
to mean average roll value tensile strength of reinforcing). The splice efficiency shall be demonstrated from
testing and shall be submitted. Splicing may consist of overlaps, fusion wedge welding, sewing, or bodkin connections.
Splicing methods that are dependent on installer experience and skill level, such as hot air and torch-applied
open flame, are not acceptable. Sewing shall include 2 lines of stitching with a Federal 401 double thread lock
stitch with a thread of the same polymer type and UV protection as the geotextile. Overlaps shall be separated
by 50 mm 2 inches of soil.
2.2 GEOTEXTILE FILTER
Geotextiles used as filters shall meet the requirements specified in Table 3. The property values (except
for AOS) represent minimum average roll values (MARV) in the weakest principal direction. For survivability
during installation, the geotextile shall meet the minimum requirements in AASHTO M 288 Class 2, and shall have
a minimum mass per unit area of 270 g/m2 8 oz/sy.
TABLE 3. GEOTEXTILE PHYSICAL PROPERTIES
PROPERTY TEST REQUIREMENT TEST METHOD
Grab Tensile, N [700 nonwoven] ASTM D 4632
[1100 woven]
Apparent Opening [150 - 212] ASTM D 4751
Size (um)
UV Resistance 80 percent after ASTM D 4355
500 hours
Permittivity, sec-1 [0.5] ASTM D 4491
TABLE 3. GEOTEXTILE PHYSICAL PROPERTIES
PROPERTY TEST REQUIREMENT TEST METHOD
Grab Tensile, lbs. [160 nonwoven] ASTM D 4632
[250 woven]
Apparent Opening [70 - 100] ASTM D 4751
Size (U.S. Sieve)
UV Resistance 80 percent after ASTM D 4355
500 hours
Permittivity, sec-1 [0.5] ASTM D 4491
2.3 TURF REINFORCEMENT MAT
Turf Reinforcement Mat (TRM) shall consist of nondegradable monofilaments; and shall meet the requirements specified
in Table 4. The property values (except for AOS) represent minimum average roll values (MARV) in the weakest
principal direction.
TABLE 4. TRM PHYSICAL PROPERTIES
PROPERTY TEST REQUIREMENT TEST METHOD
Tensile Strength, kN/m [_____] ASTM D 5035
UV Resistance 80 percent after ASTM D 4355
500 hours
Thickness, mm [8] ASTM D 5199
TABLE 4. TRM PHYSICAL PROPERTIES
PROPERTY TEST REQUIREMENT TEST METHOD
Tensile Strength, lbs/ft [_____] ASTM D 5035
UV Resistance 80 percent after ASTM D 4355
500 hours
Thickness, mils [300] ASTM D 5199
2.4 EROSION CONTROL BLANKET
NOTE: In 1999, there are 4 proposed ASTM standards for ECB's: (1) Measuring
Mass per Unit Area of Erosion Control Blankets, (2) Determination of Erosion
Control Blanket (ECB) Performance in Protecting Earthen Channels from Stormwater-Induced
Erosion, (3) Determination of Erosion Control Blanket (ECB) Performance in Protecting
Hillslopes from Rainfall-Induced Erosion, and (4) Tensile Properties Breaking
Force and Elongation of Erosion Control Blankets.
Erosion control blanket (ECB) shall consist of biodegradable open weave blankets used for establishing vegetation.
The ECB shall have a minimum mass per unit area of [_____] g/m2 oz/SY, determined in accordance with ASTM D 5261
.
2.5 SOILS AND AGGREGATES
All material placed as fill shall consist of material classified by ASTM D 2487 as GW, GP, GC, GM, SP, SM, SC,
CL, ML, or SW. The material shall be free of ice; snow; frozen earth; trash; debris; sod; roots; organic matter;
contamination from hazardous, toxic or radiological substances; or stones larger than 75 mm 3 inches in any dimension.
Each material shall be obtained entirely from one borrow source, unless the Contracting Officer determines that
quality control is adequate and the alternate source produces material that is similar in gradation, texture,
and interaction with the reinforcement. All materials shall be of a character and quality satisfactory for the
purpose intended.
a. Reinforced Fill. Soil placed in the reinforced fill zone shall consist of [granular material with
less than 35 percent passing the 75 µm No. 200 sieve].
b. Retained Fill. Soil placed in the retained fill zone shall [meet the minimum requirements above].
[c. Drainage Aggregate shall meet the requirements of ASTM D 448, size No.7].
2.6 DRAINAGE PIPE
The drainage pipe shall be corrugated polyethylene pipe meeting requirements of AASHTO M 252.
2.7 SEED
State-certified seed of the latest season's crop shall be provided in original sealed packages bearing the producer's
guaranteed analysis for mixture percentage, purity, germination, weed seed content, and inert material. Labels
shall be in conformance with AMS Seed Act and applicable state seed laws. The seed mix shall be proportioned
by weight as follows: [_____].
PART 3 EXECUTION
3.1 SHORING
Construct shoring in accordance with the safety requirements of EM 385-1-1. The Contractor is responsible for
design and maintenance of all shoring to be installed. Unless otherwise authorized, all sheeting and bracing
shall be removed when backfill is completed.
3.2 EARTHWORK
NOTE: Notification of the Contracting Officer - It is beyond the scope of a
specification to provide remedies to all possible problems. If the specification
indicates the Contracting Officer shall be notified, it is assumed qualified
assistance will be utilized to assess the situation when necessary.
The reinforced fill zone shall bear on undisturbed native soils, or acceptably placed and compacted fill. In
the event that it is necessary to remove material or place fill below the excavation lines shown on the drawings,
or not otherwise provided for in the contract, the Contracting Officer shall be notified prior to work and an
adjustment in the contract price will be considered in accordance with the contract. Additional work not authorized
by the Contracting Officer shall be at the Contractor's expense.
3.2.1 Excavation
Excavate foundation soil to the lines and grades shown on the construction drawings, and as required for reinforcement
placement. Stockpile material for backfilling in a neat and orderly manner at a sufficient distance from the
banks of the excavation to avoid overloading and to prevent slides or caving. Perform excavation and fill in
a manner and sequence that will provide proper drainage at all times. The Contractor is responsible for disposal
of surplus material, waste material, and material that does not meet specifications, including any soil which
is disturbed by the work operations or softened due to exposure to the elements and water.
3.2.2 Stockpiles
Stockpiles of all material to be incorporated into the work shall be kept in a neat and well drained condition,
giving due consideration to drainage at all times. The ground surface at stockpile locations shall be cleared,
grubbed, and sealed. Topsoil shall be stockpiled separately from suitable backfill material. Stockpiles of
aggregates and granular soils shall be protected from contamination which may destroy the quality and fitness
of the stockpiled material. If the Contractor fails to protect the stockpiles, and any material becomes frozen,
saturated, intermixed with other materials, or otherwise out of specification or unsatisfactory for the use intended,
such material shall be removed and replaced with new material from approved sources at no additional cost to
the Government.
3.3 SUBGRADE PREPARATION
Do not place material on surfaces that are muddy, frozen, contain frost, or where unsatisfactory material remains
in or under the fill. For cohesionless soils, the subgrade surface shall be compacted with the same compactor
and rolling pattern to be used for compaction of the fill. For cohesive soils, the subgrade shall be proof rolled
with rubber tired equipment and any soft areas shall be brought to the Contracting Officer's attention.
3.4 REINFORCEMENT INSTALLATION
a. Before placing reinforcement, compact the subgrade or subsequent lift of fill and level-grade it.
The surface shall be smooth and free of windrows, sheepsfoot impressions, and rocks.
b. Reinforcement shall be placed at the elevations and to the extent shown on the construction drawings
and the approved shop drawing submittal. Orient the reinforcement with the design strength axis perpendicular
to the slope face. Place reinforcement strips immediately next to adjacent strips to provide 100 percent
coverage.
c. Install the reinforcement in tension. The reinforcement shall be pulled taut and anchored with staples
or stakes prior to placing the overlying lift of fill. The tension shall be uniform along the length
of the slope and consistent between layers.
d. All reinforcement shall be 100 percent covered by soil so that reinforcement panels do not contact
in overlaps. Where the slope bends, a veneer of fill shall be placed to a nominal thickness of 75 mm
3 inches to separate overlapping reinforcement.
e. Splicing. Splicing shall not be allowed unless identified on the shop drawings. Splicing shall
be limited to only one splice per reinforcing strip and no two consecutive reinforcing strips shall include
a splice. Splices shall be located randomly without a pattern. Individual reinforcing lengths less than
3 meters 10 feet shall be discarded. Seams shall be placed facing upward for inspection purposes.
3.5 FILL PLACEMENT
NOTE: Subparagraph "b." below - Studies have documented rubber tired heavy
equipment traveling on geogrids with minimal or no damage. However, it is regarded
as poor practice and usually unnecessary. Problematic conditions include coarse
crushed gravel and coated geogrids. The intent of the specification is to minimize
equipment on the geogrid so that it occurs only when necessary.
a. Reinforced fill shall be placed from the slope face back toward the fill area to ensure that the
reinforcement remains taut. Fill shall be placed, spread, and compacted in such manner that minimizes
the development of wrinkles in or movement of the reinforcement.
b. A minimum fill thickness of 150 mm 6 inches is required prior to operation of vehicles over the reinforcement.
Sudden braking and sharp turning shall be avoided. Tracked equipment shall not turn within the reinforced
fill zone to prevent tracks from displacing the fill and damaging the reinforcement. Construction equipment
shall not be operated directly upon the reinforcement as part of the planned construction sequence.
Rubber tired equipment may operate directly on the reinforcement if the travel is infrequent, equipment
travels slow, turning is minimized, and no damage or displacement to the reinforcement is observed.
c. At the end of each day, the Contractor shall slope the last lift of fill away from chimney drains
in a manner that will allow drainage and direct runoff away from aggregate.
3.6 COMPACTION
Fill shall not be placed on surfaces that contain mud, frost, organic soils, fill soils that have not met compaction
requirements, or where the Contracting Officer determines that unsatisfactory material remains in or under the
fill. Fill shall be spread and compacted in lifts not exceeding [the height of the face wrapping].
3.6.1 Degree of Compaction
Degree of compaction required is expressed as a percentage of the maximum density obtained by the test procedure
presented in ASTM D 698. The maximum density is hereafter abbreviated as the "Standard Proctor" value.
3.6.2 Moisture Control
NOTE: Moisture content limits for compaction should be included in these paragraphs
when necessary for obtaining strength and stability in embankments and fill,
for controlling movement of expansive soils and when, in the opinion of the
project geotechnical engineer, moisture control is required for the soils being
used. Specify an acceptable variation from the optimum moisture if justified
from experience with similar soils or where demonstrated from moisture-density
tests for the borrow material during planning.
Control of moisture in the fill shall be maintained to provide acceptable compaction. Disking and plowing will
not be allowed in the reinforced fill zone. Moisture content of cohesive soils shall be adjusted at the borrow
source before placement. Adding water directly to the reinforced fill zone shall only be conducted under conditions
where the soil has sufficient porosity and capillarity to provide uniform moisture throughout the fill during
compaction.
3.6.3 Compaction
Reinforced and retained fill shall be compacted to 95 percent of the Standard Proctor Density.
3.7 SOIL TESTING
3.7.1 General
All testing expenses shall be the Contractor's responsibility. Prior to sampling and testing the work, testing
laboratories shall be inspected and approved in accordance with Section 01 45 01 USACE QUALITY CONTROL. The
Contracting Officer reserves the right to direct the location and select the material for samples to be tested
and to direct where and when moisture-density tests shall be performed. Nuclear density testing equipment shall
be used in general accordance with ASTM D 6938.
3.7.2 Transmittal
Inform the Contracting Officer of test results daily for direction on corrective action required. Draft copies
of field testing results shall be furnished to the Contracting Officer on a frequent and regular basis, as directed.
3.7.3 Corrective Action
Tests of materials which do not meet the contract requirements (failing test) will not be counted as part of
the required testing. Each such failing test must be retaken at the same location as the failing test was taken.
If testing indicates material does not meet the contract requirements, the material represented by the failing
test shall not be placed in the contract work or shall be recompacted or removed. The quantity of material represented
by the failing test shall be determined by the Contracting Officer up to the quantity represented by the testing
frequency. The Contractor may increase testing frequency in the vicinity of a failing test in order to reduce
removal requirements, as approved by the Contracting Officer. Such increases in testing frequency shall be at
the Contractor's expense and at no additional cost to the Government.
3.7.4 Testing Schedule
a. Moisture-Density Relations (ASTM D 698)
One test for each material variation[, not less than [_____] tests total].
b. In-Place Densities (ASTM D 1556 or ASTM D 6938)
Not less than 1 test for each 670 vertical mm/100 linear m 2 vertical feet/300 linear feet along
slope face.
c. Sieve Analysis, (ASTM C 136)
Drainage Aggregate, [1 test for each source].
3.8 REINFORCEMENT TESTING
NOTE: Primary reasons for testing geosynthetics include verification of quality
control by the manufacturer, detecting degradation during shipping and storage,
and verifying the correct product is supplied. Verification of quality control
by the manufacturer and detecting degradation during shipping and storage is
not economically justified for small jobs. Unlike reinforcing steel for concrete,
geosynthetics are difficult to identify in the field, and even experienced personnel
can sometimes mistake the product identity of unlabeled material. Testing after
delivery to verify the correct product was supplied may be advisable for critical
structures. The strength is usually the most critical property to verify an
acceptable product is furnished.
All testing expenses shall be the Contractor's responsibility. Testing shall be performed by a commercial testing
laboratory selected by the Contractor and approved by the Contracting Officer or performed by the Contractor
if approved by the Contracting Officer. The Contracting Officer reserves the right to direct the location and
select the material for samples.
TABLE 5. REINFORCEMENT TESTING
PROPERTY TEST DESIGNATION FREQUENCY
Wide Width Strip ASTM D 4595 [_____]
Tensile Strength
or
Single Rib ASTM D 6637 [_____]
Tensile Strength
ASTM D 4595 shall be modified for geogrids considering recommendations in GSI GRI GG6; and the tensile strength
shall be expressed on a unit length basis by substituting n*a for Ws, where:
Ws = specimen width, (mm inches)
n = number of ribs in the sample (must be a whole number)
a = nominal rib spacing for the product tested, (mm inches)
3.9 DRAINAGE PIPE
Drain pipe shall be placed as indicated on the drawings. Drain lines shall be laid to true grades and alignment
with a continuous fall in the direction of flow. The interior of the pipe shall be kept clean from soil and
debris; and open ends shall be temporarily capped as necessary.
3.10 SEEDING
Seed shall be applied at the rate of 18 square m/kg 10 square yards per pound of seed. The seed shall be evenly
distributed by hand or using broadcast seeders. Seed shall be covered to a nominal 13 mm 1/2 inch depth by rakes.
3.11 CONSTRUCTION TOLERANCES
a. Horizontal: The slope crest and toe shall be within 150 mm 6 inches of the plan location.
b. Vertical: The slope crest elevations shall be within 90 mm 0.3 feet above to 90 mm 0.3 feet below
the prescribed elevations shown on the drawings.
3.12 PROTECTION OF WORK
Work shall be protected against damage from subsequent operations.