Dynamic Behavior of a Pedestrian Bridge in Alicante, Spain

Abstract

The purpose of this paper is to study the dynamic behavior of a pedestrian bridge in Alicante, Spain, which showed vertical and horizontal vibration problems. Moreover, the deck’s structural steel showed severe corrosion damage. Hence, two cases were analyzed: before retrofitting the structure using glass fiber-reinforced polymers (GFRPs) and after. While the GFRP was designed for aesthetic and durability purposes only—and not for structural retrofitting—it changed the mass and stiffness of the footbridge, affecting its dynamic characteristics. The natural frequencies, mode shapes, and modal damping factors of the bridge were calculated based on accelerations recorded at 11 points on the bridge under different conditions—i.e., ambient vibration and forced vibration produced by a fixed number of pedestrians walking on the bridge at a certain speed and frequency. A numerical model was also designed in order to compare the experimental and numerical results.