Design and performance of a bespoke lively ALL-FRP footbridge

Abstract

This paper presents an overview into the design approach and challenges in constructing a very lively 20 m experimental bridge of Fiber-Reinforced Polymer (FRP) components. FRP composite bridges are an attractive option for footbridge construction since their lightweight nature offers engineering advantages. However, when combined with their low stiffness, such structures can result in being lively to human-induced loading conditions. Our bespoke footbridge structure was designed to consider human-structure interaction problems, as well as to develop the understanding of the dynamic response of FRP structures. Comparisons are made between the predicted design behavior and measured responses. Measured vertical bending modes are 2.53 and 8.48 Hz, with a torsional mode at 3.36 Hz, agreeing with predicted design behavior. Walking tests on the bridge demonstrate that it responses strongly to typical human pacing frequencies and actions.