06 13 35.00 18.pdf

ROCKAWAY REINFORCED DUNE AND CROSSOVER

Amendment 005

SECTION 06 13 35.00 18

STABILIZIED MAT DUNE CROSSOVERS

PART 1 GENERAL

1.1 SCOPE OF SECTION

The work covered by this section consists of furnishing all labor, materials, and equipment, and performing all operations required for the construction and removal of temporary stabilization mat crossovers, as specified herein and shown on the contract drawings.

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. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Work Plan for Temporary Stabilization Mat Dune Crossover; G, RO

SD-03 Product Data

Stabilization Mats ; G, RO

Submit information describing the quality and performance of the materials proposed with product data sheets.

SD-04 Samples

Stabilization Mat Sample Material ; G, RO

Submit a sample of the stabilization mat material to confirm the material includes a non-angular, slip-resistant surface.

SD-08 Manufacturer's Instructions

Stabilization Mat Installation and Maintenance ; G, RO

Submit stabilization mat manufacturer's installation, field repair, cleaning, and maintenance instructions.

1.3 SEQUENCING AND SCHEDULING

Reasonable public access to the beach must be provided during the course of construction of the project. Typically, portions of areas receiving beachfill are not accessible to the public until the completion of dune crossovers. In order to ensure reasonable public access, the contractor will comply with the order of work detailed in Section 01 14 00 WORK RESTRICTIONS, paragraph "Order of Work."

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1.4 Work Plan for Stabilization mat Dune Crossover

Submit typical work plans for the construction of the Stabilization mat dune crossovers. The work plans shall include the labor, equipment, and methods to be used to construct dune crossovers, and shall demonstrate how the Contractor intends to comply with Paragraph "SEQUENCING AND SCHEDULING". Prepare an individual work plan for each type of crossover.

PART 2 PRODUCTS

2.1 STABILIZATION MATS

Stabilization mats shall be ABA/ADA compliant and shall provide a firm and slip resistant, flexible surface for pedestrian beach access with the following features:

a. Minimum continuous roll width of 66 inches 5 feet for walkway behind the dune between Beach 149th St and Beach 126th St. Minimum width of 6 feet 6 inch for all on grade crossovers type P1, P3 and P4. .

b. Minimum roll length of 30 feet.

c. Minimum weight not less than 0.24 lbs/sf and individual rolls shall be of such size and weight that they may be manageably moved by two people.

d. Manufactured from durable, UV stabilized material that is rot-proof and rust-proof in material and construction, and able to withstand extensive pedestrian and wheelchair traffic.

e. Material shall have a flat, open weave structure and finished edges to accommodate the anchoring devices required for installation.

f. Manufactured to provide a slip resistant surface in wet conditions and a non-angular comfortable walking surface for bare foot usage.

g. All components shall arrive fully factory fabricated and ready for field installation.

h. Color to be selected by Contracting Officer from manufacturer's standard colors.

i. Stabilization mat dune shall extend as shown on the plans. Typical mat shall extend from the landward existing grades, up and cross the dune, slope down to seaward toe of dune. Mats shall slope as shown on the plans and cross sections.

Provide Sample Material meeting requirements stated above.

2.1.1 Connectors

Furnish stabilization mats with an integral connector strip on each end of the mat with predefined, reinforced holes in the mat connector strip.

Connectors shall provide a factory manufactured method to seamlessly connect mats together at the ends.

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2.1.2 Anchoring

Provide U-shaped galvanized or plastic pins to facilitate the installation and anchoring of the stabilization mats. Anchors shall be approximately six inches wide and a minimum 16 inches deep.

PART 3 EXECUTION

3.1 RESTRICTIONS ON DUNE CROSSOVER CONSTRUCTION

Refer to order of work under Section 01 14 00 WORK RESTRICTIONS, paragraph

13.1 Order of Work for restriction and sequence of dune crossovers.

3.2 SITE PREPARATION

Crossover construction may require, clearing and grubbing of dune vegetation and dune grass, and the removal of sand fence and posts. Clear and grub and remove existing structures only to the extent necessary for the installation of crossovers.

3.2.1 Clearing

Clearing shall consist of the satisfactory removal and disposal of vegetation, including snags, brush, and rubbish occurring within the areas to be cleared as necessary for the temporary crossover construction.

Stumps, roots, brush, and other vegetation in areas to be cleared shall be removed in their entirety. Dispose of cleared material off-site.

3.2.2 Grubbing

Grubbing shall consist of the removal and disposal of stumps, roots larger than 3 inches in diameter, and matted roots. Material to be grubbed, shall be removed to a depth of not less than 18 inches below the original surface level of the ground. Fill depressions made by grubbing with suitable beachfill material and compact to make the surface conform with the original adjacent surface of the ground. Dispose of grubbed material off-site.

3.2.3 Existing Sand Fence Demolition

Remove existing sand fence, including fencing and posts, that are in the footprint of the temporary stabilization mat crossover. All sand fence to be demolished shall first be approved by the Contracting Officer. Dispose of demolished sand fence material off-site.

3.2.4 Existing Structures Demolition

Existing stairs, ramps and other structures in conflict with reinforced dune and as shown on the drawings shall be demolished. No demolition debris shall be buried in the new dune fill. All structures to be demolished shall be approved by the Contracting officer. Dispose of the demolished structure materials off-site.

Geo-bag and trap bags in Dune footprint shall remain in place and shall be removed if they are in Berm footprint.

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3.2.5 Excavation

Minimize excavation of existing or constructed dunes to facilitate temporary crossover construction. Stockpile excavated sand free of vegetation for reuse in restoring dune to its preconstruction configuration. Slope of temporary stabilization mat crossovers shall be no steeper than 1V:12H.

3.2.6 Temporary Stabilization Mat Dune Crossover Removal

Remove all existing mats as they shall be replaced with new mats.

3.2.6.1 Dune Reconstruction

Reconstruct disturbed dune utilizing the stockpiled material to the template and specific limits and sections as shown in the drawings.

Vegetate the dune. Newly placed fill shall be keyed into the existing dune.

3.2.6.2 Sand Fence and Existing Structure Reconstruction

Reconstruct all demolished sand fence and existing structures to pre-construction conditions or as directed by the COR.

3.3 STABILIZATION MAT INSTALLATION

3.3.1 STABILIZATION MAT INSTALLATION AND MAINTENANCE

a. Prepare the surface where the stabilization mats will be placed by raking the beach dune. Remove debris and foreign objects from the area.

The surface should be as smooth and flat as possible with slopes no steeper than 1V:12H.

b. Unroll the stabilization mat fully. Install the mat with the walking surface facing up.

c. Where the stabilization mat meets permanent pedestrian access structures on the landward side, the mat end shall be placed so there is no gap. Set the mat flush or below the permanent path to eliminate a tripping hazard. Dig a one to two inch trench and tuck the end of the mat into this trench and cover end of mat with beach sand.

d. Anchor the mat end using U-shaped pin anchors across the connector strip. Install the pins in the predefined holes in the mat connector strip. A connector strip is supplied on each end of the stabilization mat.

e. Anchor the beach end of the mat by digging a three inch trench. Fold the end of the mat into the trench firmly securing this end with four anchor pins inserted through the predefined holes in the mat connector strip.

f. Rake sand over the trench covering the end of the mat to prevent a tripping hazard.

3.3.1.1 Connecting Stabilization Mats

a. Install the successive mats by overlapping the connector strips, ensuring that the anchoring holes are lined up so that the anchor pins anchor both mats securely together.

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b. Secure the mats with four U-shaped pins at each seam or as recommended by the mat manufacturer.

c. Continue connecting mat sections for the length of the access route.

Complete the installation by securing the end of the final stabilization mat section as specified above or per manufacturer's instructions.

3.4 MEASUREMENT AND PAYMENT

3.4.1 Stabilization Mats

The work specified in this section for the installation of stabilization mats will be measured for payment by the linear footage of stabilization mats satisfactorily installed and accepted. All costs in connection therewith shall be included in the contract unit price for the Bid Items titled, "Stabilization Mats".

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