31 05 19.19.pdf

Emsworth L/D - Back Channel Left Abutment Stabilization and Scour Protection

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 05 19.19

GEOGRID REINFORCEMENT

PART 1 GENERAL

1.1 REFERENCES

1.2 SUBMITTALS

1.3 MANUFACTURER

1.4 DELIVERY, STORAGE AND HANDLING

1.4.1 Labeling

1.4.2 Handling

1.4.3 Storage

PART 2 PRODUCTS

2.1 GEOGRID REINFORCEMENT

2.1.1 Geogrid Reinforcement Properties

2.1.1.1 Allowable Strength

2.1.2 Splices

PART 3 EXECUTION

3.1 INSTALLATION

3.1.1 Subgrade Preparation

3.1.2 Placement

3.1.3 Overlaps and Fasteners

3.1.4 Splices

3.1.5 Penetrations

3.2 OVERSIGHT

3.3 CONFORMANCE TESTING

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SECTION 31 05 19.19 Page 1 W911WN-10-B-0006 Revised by Amendment 0001

SECTION 31 05 19.19

GEOGRID REINFORCEMENT

PART 1 GENERAL

1.1 REFERENCES

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.

ASTM INTERNATIONAL (ASTM)

ASTM D 4355 (2007) Deterioration of Geotextiles from Exposure to Light, Moisture and Heat in a Xenon-Arc Type Apparatus

ASTM D 4595 (2009) Tensile Properties of Geotextiles by the Wide-Width Strip Method

ASTM D 4873 (2002) Identification, Storage, and Handling of Geosynthetic Rolls and Samples

ASTM D 5262 (2007) Evaluating the Unconfined Tension Creep Behavior of Geosynthetics

ASTM D 5321 (2008) Determining the Coefficient of Soil and Geosynthetic or Geosynthetic and Geosynthetic Friction by the Direct Shear Method

GEOSYNTHETIC INSTITUTE (GSI)

GSI GRI GG1 (1987; R 1988) Geogrid Rib Tensile Strength

GSI GRI GG4a (1991) Determination of the Long-Term Design Strength of Stiff Geogrids

GSI GRI GG4b (1991) Determination of the Long-Term Design Strength of Flexible Geogrids

GSI GRI GG6 (1996) Grip Types for Use in Wide Width Testing of Geotextiles and Geogrids

GSI GRI GG5 (1991) Test Method for Geogrid Pullout

1.2 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for 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

SECTION 31 05 19.19 Page 2

Installation; G|RE

Geogrid layout plan along with anchorage and joint details.

Sequencing and construction procedures shall also be included.

Proposed geogrid layout shall be provided a minimum of 7 days prior to geogrid placement.

SD-03 Product Data

Allowable Strength

Geogrid allowable strength calculated in accordance with GSI GRI GG4a or GSI GRI GG4b. The calculations shall itemize each reduction factor. Splice efficiency shall be accounted for in the calculations. Calculations shall be provided a minimum of 7 days prior to delivery of geogrid to the site.

Manufacturer

Summary of manufacturer's qualifications a minimum of 7 days prior to delivery of geogrid to the site. Manufacturer's quality control (QC) manual a minimum of 7 days prior to the delivery of geogrid to the site.

SD-04 Samples

Geogrid Reinforcement

One properly identified 24 inch by 24 inch minimum size geogrid sample. The fasteners proposed for use shall also be submitted.

SD-06 Test Reports

Geogrid Reinforcement

Manufacturer's certified raw and roll material test reports.

Roll material tests shall include ultimate strength performed in accordance with GSI GRI GG1 or ASTM D 4595 (modified). Test results not meeting the requirements in Table 1 or in the approved Manufacturer's Quality Control Manual will result in rejection of applicable rolls. Certified test reports shall be provided a minimum of 7 days prior to delivery of geogrid to the site.

Splices

Test data showing splice efficiency. Certified test results shall be provided a minimum of 7 days prior to delivery of geogrid to the site.

Conformance Testing

Results of conformance testing.

SD-07 Certificates

Certificates of Compliance

The Contractor shall submit an affidavit certifying raw and roll material test results submitted are accurate and that the

SECTION 31 05 19.19 Page 3 reinforcement meets the requirements of the project specifications. The affidavit shall be signed by an official authorized to certify on behalf of the manufacturer. 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. Affidavit shall be provided a minimum of 7 days prior to delivery of geogrid to the site.

1.3 MANUFACTURER

The Contractor shall submit a summary of the manufacturer's qualifications and 6 copies of the manufacturer's quality control manual, as specified in the paragraph "Submittals". The reinforcement manufacturer shall provide a qualified and experienced representative to be available on an as-needed basis during construction. The representative shall visit the site for consultation as requested by the Contracting Officer.

1.4 DELIVERY, STORAGE AND HANDLING

The Contractor shall check products upon delivery to assure that the proper material has been received and is dry and undamaged. The Contractor shall protect the materials from damage and exposure following the guidelines presented in ASTM D 4873.

1.4.1 Labeling

Each roll shall be labeled with the manufacturer's name, product identification, roll dimensions, lot number, and date manufactured.

1.4.2 Handling

Geogrid 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.

1.4.3 Storage

Geogrid shall be protected from deleterious materials, chemicals, sparks and flames, temperatures in excess of 160 degrees F, and any other environmental condition that may degrade the physical properties. If stored outdoors, the rolls shall be elevated from the ground surface.

Geogrids, except for extruded grids, shall be protected with an opaque waterproof cover.

PART 2 PRODUCTS

2.1 GEOGRID REINFORCEMENT

Geogrid shall be 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, SECTION 31 05 19.19 Page 4 transport and installation. The geogrid shall be manufactured with 100 percent virgin resin consisting of polyethylene, polypropylene, polyester, or other approved material 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. The Contractor shall submit Certificates of Compliance for the materials provided as specified in the paragraph "Submittals".

2.1.1 Geogrid 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

Allowable Strength (Ta) 580 lb/foot in MD GSI GRI GG4a at 5 percent strain 920 lb/foot in XMD or GSI GRI GG4b

UV Resistance 10070 percent after ASTM D 4355 500 hours

Coefficient of Interaction for Pullout 0.83 GSI GRI GG5

Interface Friction at 30 ASTM D 5321 Residual, Degrees

2.1.1.1 Allowable Strength

Ta shall be based on reduction factors for installation damage, durability, and creep that are applicable to site specific conditions. Reduction factors shall be determined in accordance with the test procedures documented in GSI GRI GG4a or GSI GRI GG4b. The minimum reduction factor for durability shall be 1.1 for polyethylene and polypropylene geogrids and

1.15 for coated polyester geogrids. The minimum reduction factor for installation damage shall be 1.1 for all polymers. The reduction factor for creep shall be based on testing performed in accordance with ASTM D 5262 at the strain specified in Table 1.

2.1.2 Splices

Splices shall consist of a standard method or device recommended by the manufacturer of the geogrid. Splices shall not be allowed unless identified on the approved layout drawings. Splices shall be at least 75 percent efficient. The splice efficiency shall be demonstrated through tests performed in accordance with GSI GRI GG4a or GSI GRI GG4b. 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. Overlap splices shall be constructed by placing a minimum of 2 inches of soil between the layers of geogrid.

SECTION 31 05 19.19 Page 5

PART 3 EXECUTION

3.1 INSTALLATION

3.1.1 Subgrade Preparation

Immediately prior to placement of the geogrid, the surface on which the geogrid will be placed shall be free of rock and other material that could damage the geogrid or the underlying geosynthetics.

3.1.2 Placement

The geogrid shall be installed in accordance with the Manufacturer's recommendations. Geogrid shall be unrolled in the direction of reinforcement. After a layer of geogrid has been placed, suitable means, that do not damage the underlying geosynthetics, shall be used to hold the geogrid flat and in place until the grout bags can be placed. Geogrid damaged during placement and installation of grout bags shall be removed and replaced at no additional cost to the Government.

3.1.3 Overlaps and Fasteners

Adjacent rolls of geogrid shall be positioned edge-to-edge and loosely fastened to maintain alignment during fill placement. Adjacent rolls shall not be overlapped. Fastener type and spacing shall be as recommended by the manufacturer and approved by the Contracting Officer. Metallic fasteners will not be allowed.

3.1.4 Splices

Splices, if allowed, shall be located within the bottom one-third of the slope. Splicing shall be limited to only one splice per reinforcing strip and no two consecutive reinforcing strips shall include a splice.

Individual reinforcing lengths less than 10 feet shall not be used.

Splices in geogrid reinforcement shall be pulled and held taut during cover soil placement.

3.1.5 Penetrations

For small penetrations through geogrids, only transverse members of the geogrid shall be cut. The load-carrying longitudinal (machine direction) members shall be spread around the penetration. For larger penetrations, additional geogrid shall be placed on each side of the penetration and spliced to the adjacent geogrid to compensate for any longitudinal tensile members that must be cut.

3.2 OVERSIGHT

The Contractor shall provide a QA Representative, per Section 01 45 01 USACE QUALITY CONTROL, that shall be present at all times during geogrid installation to verify installation and report to the Contracting Officer.

3.3 CONFORMANCE TESTING

Conformance testing expenses shall be the responsibility of the Contractor. Testing shall be performed by a commercial testing laboratory selected by the Contractor and approved by the Contracting Officer. The laboratory shall be accredited via the Geosynthetic Accreditation Institute's Laboratory Accreditation Program (GAI-LAP) for the tests the

SECTION 31 05 19.19 Page 6 laboratory will be required to perform. The Contracting Officer reserves the right to direct the location and select the material for samples.

Conformance test results must equal or exceed results reported on the Manufacturer's certified roll material test reports.

TABLE 2 CONFORMANCE TESTING

PROPERTY TEST DESIGNATION FREQUENCY

Wide Width Strip ASTM D 4595 (mod) 1 Test per 20,000 SF Tensile Strength

ASTM D 4595 shall be modified for geogrids considering recommendations in GSI GRI GG6. The tensile strength shall be expressed on a unit length basis by substituting n*a for Ws, where:

Ws = specimen width, (inches) n = number of ribs in the sample (must be a whole number) a = nominal rib spacing for the product tested, (inches)

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SECTION 31 05 19.19 Page 7

2.1.2 Splices