A04_Specifications_REDW_Bridge.pdf

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Specifications Redwood National and State Parks Prefabricated Bridge Support Kits

Solicitation # 140P8424Q0018

I. Background:

The National Park Service (NPS) at Redwood National and State Parks (REDW) has a requirement to replace four deteriorated trail bridges along the upper section of the Redwood Creek Trail within Redwood National Park. These bridges were constructed of wooden components and shall be replaced with longer lived materials. The new structures will utilize prefabricated fiber reinforced plastic (FRP) components. The freestanding bridge components shall come prefabricated and will be re-assembled on site by Redwood National and State Park staff. The new bridges shall serve as pedestrian crossings, with occasional use by motorized and mechanized trail maintenance equipment and vehicles such as ATVs pulling trailers loaded with materials.

II. Description of work:

This acquisition shall purchase four (4) single span simply supported beam structure systems, pre-engineered and prefabricated to be utilized to replace the existing pedestrian trail bridges.

This work includes design, fabrication, and delivery to the park as a kit. The structural components shall be made of pultruded fiber-reinforced plastic (FRP), be below the decking and supported on cement abutments. The vendor will provide the dimensions of the bearing surface and depth needed for anchor bolts, size, numbers, and locations of anchor bolts in the abutment. The existing cement abutments shall be reutilized, and the vendor shall include them in the design development. Although the government shall supply and install the decking, posts and handrails, the vendor shall include them in the design development. All fasteners and hardware shall be Hot Dipped Galvanized and/or Stainless Steel.

• Each bridge structure shall be 54 inches wide and span 28 feet, have no fewer than three structural beams and include lateral bracing, at a minimum at each end, as necessary to minimize, harmonics, side-sway, flex, and bounce.

The design and fabrication shall be in a simple manner, such that it will allow disassembly for shipping, and allow for the park to manually manipulate and transport bridge components to the trail bridge sites for re-assembly by manual labor crews and hand tools. No component shall be longer than 28 feet, to accommodate restrictive terrain and allow moving components by manual labor crews.

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This work does NOT include posts, rails, decking and associated hardware. However, the design should include loading and calculations as required to support the decking, handrail and post connections and attachments on the structure. The government shall furnish and install: the 1.3’’X 5.5” plastic composite decking with 0.5’’gaps in between boards; 1.3”X 5.5” plastic composite lumber handrails (two per side); and the 3.5” X 5.5” recycled plastic lumber posts, spanned approximately 5 feet apart and attached directly to the outside edge of stringers.

A. Engineering Requirements Each bridge structure shall be designed and stamped by a California Professional Engineer. Include all applicable codes and design criteria (such as, but not limited to live load, dead load, wind loads, seismic loads, etc.)

B. Design Criteria

1. Provide designs for the 28ft span length and 54in decking width.

2. Design in accordance with AASHTO’s LRFD Guide Specifications for the Design of Pedestrian Bridges.

3. Design to withstand and accommodate motorized and mechanized trail maintenance equipment and vehicles with a minimum of 5,000lbs live load.

4. Support structures for bridges shall be able to accommodate the secure attachment of the 1.3’’X 5.5”X 54” deck boards and 3.5” X 5.5” posts.

5. Design for a handrail at 48’’ rail height above decking. Designer shall determine the required design loads for pedestrian traffic. In no case shall this loading be less than described in AASHTO’s LRFD Bridge Design Specifications:

a) Design for rails for a uniform load of 85-pounds per linear foot simultaneously applied horizontally and vertically and a 200-pound load simultaneously applied at the most critical location and most critical direction.

b) Design for each post connection for the uniform horizontal load acting on the top rail simultaneously with a 200-pound horizontal load at the top rail post critical direction.

6. All bridges shall utilize a simply supported FRP beam system (minimum of three beams) sufficient to carry loads, support decking, and to allow for the attachment of a park installed post and handrail systems.

III. Submittals:

A. Shop Drawings:

Provide shop drawings for review and acceptance. Provide design criteria, component dimensions, layout, assembly instructions and PE stamp.

1. Provide shop drawings for bridge structure

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2. Provide shop drawing for details of minimum bearing area of concrete abutment with anchorage details.

3. Provide shop drawings showing locations for attaching decking and posts and with recommended size and type of fasteners.

B. Assembly Instructions and Requirements.

Provide step by step written instructions. Include photos of completed factory assembled structures prior to disassembly and shipment.

C. Spare Parts:

Provide (2) sets of spare parts for each type of fastener or hardware.

D. Warranty:

Provide manufacturer warranty for materials.

IV. Quality Control:

Manufacturer shall fabricate and assemble the bridge structures to verify assembly, component size/type and fit are accurate.

Disassembly, itemize and label components, develop and include assembly instructions for delivery.

V. Shipping and Delivery:

Disassemble and ship all materials, fasteners, etc. to:

Redwood National Park, North Operations Center 500 Aubell Lane Crescent City, CA 95531.

Delivery shall be arranged to occur during the hours of operation, Monday to Thursday, 7:00 AM to 5:00 PM.

VI. Schedule:

A. Complete fabrication and factory QC no later than 40 days after Award.

B. Ship to park no later than 50 days after award.

C. Delivery no later than 60 days.

6. All bridges shall utilize a simply supported FRP beam system (minimum of three beams) sufficient to carry loads, support decking, and to allow for the attachment of a park installed post and handrail systems.