Case study of first all-GFRP pedestrian bridge in Taiwan

• To prevent corrosion, GFRP composite was used to build the first all-FRP composite pedestrian bridge in Taiwan.
• The girder-deck system of the bridge is composed of four girders, decks and bridge diaphragms.
• Terrestrial Laser Scanner (TLS) was used to produce a digital 3D model of the bridge for archiving.
• A finite element model of the girder-deck system was made after verifying that of an 8-m girder.
• Finite element results show that the girder-deck system met deflection goals of the pedestrian bridge.

To forestall the severe deterioration of structures as a result of corrosion, the first all-FRP composite pedestrian bridge was built in Tainan, Taiwan. The bridge superstructure was designed by placing Glass Fiber Reinforced Polymer (GFRP) decks onto four FRP I-girders that served as the bridge girders. Bridge diaphragms and FRP rods placed between the girders helped dissipate the loading to the other girders and prevent torsion respectively. The pultruded GFRP composite profiles were used in constructing this bridge located in the Taijiang National Park of Taiwan. This paper discusses the features of the pedestrian bridge and the detailed design of all the components of the bridge. A new method of digitally archiving the pedestrian bridge using a 3D terrestrial laser scanner was also presented. Lastly, results of the theoretical analysis were compared with the finite element analysis (FEA), to predict the static flexural behavior of an 8-m girder under loadings. After agreement of the theoretical results (using Timoshenko Beam Theory and Euler–Bernoulli Beam Theory) and the FEA results, the pedestrian bridge superstructure was modeled and analyzed. Deflection results obtained from the FEA showed that the pedestrian bridge meets the deflection criteria.