Truss-type Segmental Composite Structure for Temporary Rescue Bridges

Truss-type Segmental Composite Structure for Temporary Rescue Bridges

Typhoons and earthquakes, which occur frequently in Taiwan, often lead to the washout or collapse of river bridges, thereby causing traffic interruption. When a bridge structure loses workability, constructing a temporary rescue bridge is an effective disaster relief operation. In this study, a truss-type segmental composite temporary rescue bridge is proposed to improve the stiffness of longer span (50 m) bridges. A 50-m-span asymmetric self-anchored truss-type segmental cable-stayed bridge is designed, and experimentally validated. The autonomous assembly technology proposed for construction is validated via an on-site experiment and a simulation. The assembly process is found to improve worker safety during bridge construction and shorten the assembly time of the bridge. Two construction processes, namely the cantilever erection method and the incremental launching method, are compared to improve worker safety. The results of this study indicate that (1) the truss-type segmental composite bridge can improve the stiffness of a 50-m-span temporary rescue bridge, thus meeting the required deflection-tospan ratio; (2) autonomous assembly technology for bridge construction significantly improves worker safety and shortens the assembly time of the temporary rescue bridge; (3) the incremental launching method has greater operational efficiency than the cantilever erection method; and (4) the incremental launching method can avoid construction of the bridge over a river, thus providing better safety to the workers.