Bridge Product Gateway
Pedestrian Bridges

Introduction

During the past 20 years, FRP composite pedestrian bridges have provided walkway solutions for both industrial and public applications. Due to increased demand in backcountry locations for recreational activities such as hiking, biking, horseback riding, and off-road vehicles, FRP composite pedestrian bridges have expanded trail and greenway uses into areas where traditional bridge building has been more difficult. Over 100 FRP pedestrian bridges for public use have been installed worldwide.  Hundreds more have been installed in industrial applications as walkways or catwalks.  Most FRP composite pedestrian bridges installed for public use have spans ranging from 15 ft. (5m) to 100 ft. (30m).  However, spans in excess of 200 ft. (65m) have been built.

FRP pedestrian bridge framing system components are manufactured by the process in a quality-controlled environment. High-strength FRP materials such as glass or carbon fiber reinforcements provide the bridge system with a strength-to-weight ratio greater than steel, offering significant design and erection advantages. The FRP pedestrian bridge system use typical structural profiles including wide-flange beams, channels, angles, and tubes. The FRP structural profiles could be prefabricated offsite, and transported in lightweight component assemblies to the site.

FRP composite materials are inherently corrosion-resistant. This unique FRP materials quality eliminates the ongoing maintenance concerns from moisture, salt air, and termites that pose problems for typical pedestrian bridges constructed in steel, wood and concrete. This life-cycle performance of a pedestrian bridge is important on most projects in remote sites, as access to the site for inspection and repair is often not readily available after initial construction.

Features and Benefits

• High Strength – Standard components have strengths ranging between 30,000 - 60,000 psi.

• Light Weight – Standard components can be easily carried. The bridge spans can be erected in most locations.

• Modular Construction – Bridge spans can be shipped fully assembled, partially assembled or completely disassembled depending on site or project requirements.

• Easy Installation – Bridge spans are designed for quick and easy installation and assembly.

• Low Maintenance – The FRP materials perform well in harsh environments that quickly deteriorate more traditional materials. Wet locations, termites, salt, and most chemical environments have no effect on the material. FRP composites are electrically non-conductive and easy to clean.

• Attractive Appearance – The bridge system can be specified in any color. The color is pigmented in the resin. Therefore, painting is not necessary.

Design

FRP structural profiles are designed using traditional framing systems to produce the FRP pedestrian bridge. The selection and design of the framing system is dependent on the owners’ needs, loading, and site conditions. The walkway wearing surface could be designed using wood, concrete, or FRP composites in the form of panels or open-hole grating, depending on the bridge owner’s requirements. Consult the FRP bridge supplier for design guidance. Examples of FRP composite pedestrian bridge structural configurations are, but not limited to:

• Pratt Truss

• Howe Truss

• Pony Truss

• X-Braced Truss

• Arch Truss

• Cable stayed

• Suspension

Connections

FRP structural framing components are connected with mechanical bolts. All bolted connections are designed as bearing type connections. In some cases, use of adhesive bonding could be used but only in conjunction with bolted connections. Separate mounting clips may be required by the design. Clips are securely attached to the foundation as required to provide adequate vertical and horizontal support.

Assembly and Installation

Bridge installations used in remote locations benefit from the high-strength and lightweight characteristics of FRP composite materials.  FRP pedestrian bridge systems can be transported and installed without use of the typical construction machinery, and without causing damage to fragile ecosystems at the bridge site. The FRP structural components are designed into an efficient system providing for an extremely cost effective solution.  FRP pedestrian bridges are often located over existing high-volume traffic zones or in recreational areas with limited access. In these circumstances, bridge owners desire to have minimum impact on traffic patterns or the site’s natural surroundings.

FRP pedestrian bridges can be assembled and installed in a variety of ways. Spans can be shipped to the site previously assembled, partially assembled or in component parts. If shipped partially assembled or unassembled, the spans can be assembled using standard hand tools. The FRP materials lightweight characteristic allows for quick installation on site with a small work crew. Assembly of the FRP structural components on site might require temporary supports and/or rigging depending on the job requirements. The system can also be easily installed using a small crane, helicopter, or even a forklift truck. For applications where FRP bridges are attached to existing bridge structures, FRP composite brackets can be used to support the bridge structure to provide easy installation. The FRP pedestrian bridge system’s easy assembly and installation is an important benefit compared with other traditional systems constructed in steel, concrete or wood.

Conclusion

FRP composite pedestrian bridges offer a cost effective alternative to traditional construction materials. The added benefits of low maintenance / life cycle costs offset any higher initial project cost. Given today’s concerns with replacement costs, FRP pedestrian bridges become an attractive option when compared to steel, concrete, and wood. Further, for existing vehicular and railway bridges where there is a need to add pedestrian access, FRP bridges offer the lightest and most easily installed solution to the problem.

Pedestrian Bridge Suppliers

Bridge Product Gateway provided by:
Market Development Alliance of the FRP Composites Industry
600 Mamaroneck Avenue
Harrison, NY 10528
P: 914-381-3572 F: 914-381-1253 E: info@mdacomposites.org