A04_-_SOW_2026_RBAL_SOW_Pedestrian_Bridge_9_1_2026.pdf

United States Department of the Interior Statement of Work RBAL Pedestrian Bridge

BUREAU OF LAND MANAGEMENT

http://www.blm.gov

Overview

A. The Bureau of Land Management (BLM), Roswell Field Office has the requirement for two pre-manufactured steel superstructure and deck tread path pressure treated lumber pedestrian bridges with substructure abutments. The contract will include structurally designed plans for the pedestrian bridge, timber deck materials, and anchor bolts with delivery to BLM project site located near Lincoln NM. Unloading and labor will be the responsibility of the contractor.

General

B. These Guide Specifications shall apply to bridges intended to carry primarily bicycle, pedestrian, and maintenance foot traffic.

C. Prepare a pedestrian bridge that BLM will install over Rio Bonito River in Lincoln NM at Rio Bonito

Acquired Lands (RBAL) trail network. It is intended to be a year-round pedestrian and bicycle bridge.

D. These specifications are for a fully engineered prefabricated bridge and shall be regarded as minimum standards for design and prefabricated build.

E. Structure. The manufacturer shall provide the bridge in kit form that is easily transportable, and easily assembled with ordinary hand tools.

F. Qualified Suppliers: The bridge manufacturer shall have been in the business of design and fabrication of bridges for a minimum of five years and provide a list of five successful bridge projects of similar construction, each of which has been in service at least three years. List the location, bridge size, owner and contact reference for each bridge.

2.0 Bridge and Design Requirements

A. Structural Design Requirements o Live load – 90PSF o Ground snow load – 43PSF o Wind – 90 MPH w/ 115MPH gust o Exposure - B o Seismic zone – 2B

B. The overall superstructure length for the bridge (span) shall be measured 30-feet from each end of the bridge structure.

C. Bridge deck width shall be 48" wide and composed of treated timber material.

D. Railing shall be a minimum of 54” above the deck surface. Railing shall conform to the International building code (IBC) and ADA Standards for Accessible Design.

E. The bridge will be placed on concrete sill beam abutments that are square, aligned, at the same elevation on both ends. Concrete sill beams will be furnished by the contractor.

F. Bridge System Type: Bridges must be designed as a steel truss Span.

G. Member Components: All members shall be fabricated from steel and pressure treated lumber and structural shapes as required.

H. Camber: none.

I. Anchor bolts shall be supplied to anchor the bridge to concrete sill beams.

J. Use the appropriate load and combination of loads given in the AASHTO manual in the design of all trail bridges. AASHTO Guide Specifications for Design of Pedestrian Bridges is another useful reference for trail bridge design. Accommodate both pedestrian and equestrian traffic in the design loads for trail bridges and apply it full-length or partially, whichever produces the maximum stress.

From MS 9112 Bridge and Major Culvert (BLM internal guidance)

2.1 Pedestrian Live Load Main Members

A. Main supporting members shall be designed for a pedestrian live load of 90 pounds per square foot

(psf) of bridge walkway area. The pedestrian live load shall be applied to those areas of the walkway to produce maximum stress in the member being designed.

B. Secondary Members, bridge decks and supporting floor systems, including secondary stringers, floor beams, and their connections to main supporting members, shall be designed for a live load of 90psf, with no reduction allowed.

2.2 Wind Loads

A. A wind overturning force shall be applied according to Article 3.15.3 of the Standard Specifications for

Highway Bridges.

2.3 Combination of Loads

A. The load combinations, i.e., allowable stress percentages for service load design and load factors for load factor design as specified in Table 3.22.1A of the Standard Specifications for Highway

Bridges, shall be used with the following modifications:

• Wind on Live Load, WL, shall equal zero

• Longitudinal Force, LF, shall equal zero

3.0 Design Details

3.1 Deflection

A. Members should be designed so that the deflection due to the service pedestrian live load does not exceed 1/400 of the length of the span. The deflection of cantilever arms due to the service pedestrian live load should be limited to 1/200 of the cantilever arm. The horizontal deflection due to lateral wind load shall not exceed 1/400 of the length of the span.

3.2 Vibrations

A. The fundamental frequencies of the pedestrian bridge in the vertical and horizontal directions should be different to avoid potential adverse effects associated with the combined effects from the first and second harmonics in these directions.

3.3 Allowable Fatigue Stress

A. Standard fatigue provisions do not apply to steel and wood composite pedestrian bridge live load stresses as heavy pedestrian loads are infrequent and steel and wood composite pedestrian bridge design is generally governed by deflection criteria. Wind load concerns are also governed by deflection criteria.

3.4 Minimum Thickness of Bridge

A. Minimum thickness of closed structural tubular members shall be 0.25 inch. Minimum thickness of open structural members shall be 0.375 inch. Plate connections also require a minimum thickness of 0.375 inch.

3.5 Connections

A. Under this specification, bolted connections shall be used for all main and secondary members.

Use only galvanized or stainless-steel bolts. Adhesive bonding can be used in conjunction with bolted connections for all main members and secondary members. Non-structural members can be either bolted/screwed or adhesively bonded.

3.6 Seismic Loads

A. Seismic loads shall be determined according to the criteria specified in the standard building codes (IBC 2006, ASCE 7-05).

4.0 Engineering

A. Structural design of the bridge structure(s) shall be performed by or under the direct supervision of a

Licensed Professional Engineer and done in accordance with recognized engineering practices and principles.

4.1 Serviceability Criteria

A. Service loads are used for the design of all structural members when addressing deflection and vibration issues.

5.0 Materials

5.1 FRP Composites

A. Steel and wood bridges shall be fabricated from calculations of Professional Engineer (PE) stamped drawings.

5.2 Decking

A. Wood decking shall be treated No. 2 Southern Yellow Pine or Douglas Fir No. 2, 2-inch x 10 inch (or) 12-inch planks.

5.3 Hardware

A. Bolted connections shall be hot-dipped galvanized steel unless otherwise specified. Mounting devices shall be galvanized or stainless steel.

6.0 Submittals

A. Bidders shall provide a detailed, itemized quote for all bid items (bridge with drawings and calculations, and shipping)

B. Bidders shall submit preliminary drawings and specifications showing all items addressed in this statement of work

C. Once awarded manufacturer is to provide finalized structural drawings, specifications and complete design structural calculations with references for the superstructure, and anchor bolts. Structural calculations and drawings must be signed by a Professional Engineer.

D. Operation and maintenance manual, installation instructions and warranty documentation.

6.1 Submittal Drawings

A. Schematic drawings and diagrams shall be submitted to BLM for approval after receipt of order. As required, all drawings shall be signed and sealed by a Professional Engineer.

6.2 Submittal Calculations

A. Structural calculations shall be submitted to BLM. All calculations shall be signed and sealed by a

Professional Engineer.

6.3 Manufacturer’s Qualifications: as stated in paragraph 2.0D.

6.4 Assembly: Provide instructions to assemble the bridge.

7.0 Fabrication

7.1 Tolerances

A. No material deviations beyond industry standards are accepted. All cut edges to be cleaned and sealed.

8.0 Railings

A. Railings shall be a minimum of 54” above the floor deck.

B. Continuous horizontal midrails shall be located on the inside of the trusses. Maximum opening between the midrails shall not be greater than 4”.

C. Toeplates shall be installed.

9.0 Finishing

A. Bridge color shall be from manufacturer’s standard colors. Supply a color list for BLM to choose.

10.0 Delivery

A. Bridge shall be delivered within 60 days from the date of the award

B. Decking and other accessories may come separate as long as they are packaged for outdoor storage and movable with a forklift.

C. Coordinate with BLM for delivery.

D. Delivery Coordinates: 33.494789, -105.391062

E. Contact Contracting Officer Representative to schedule delivery.

F. Pallets or containers of parts shall not weigh more than 2,400 lbs.

11.0 Warranty

A. The manufacturer shall warrant the structural integrity of all materials, design, and workmanship for 15 years.

END OF SECTION