Structural Performance of Hybrid Timber Girder Highway Bridge

The timber highway bridge (Maruyamasawa Bridge) objected in this study is a new hybrid type structure which is prestressed by four steel wires inserted into glulam (glue laminated timber) main girder. The main design geometry is as, span length: 19m, clear width: 7m. By this hybrid structure, long span and light weight of a main girder, and simplify of joint part by high tension bolts are expected. The bridge is constructed as the first to the hybrid timber girder bridge in Japan in 2003. For investigation of structural characteristics, the static and dynamic field tests were done with two dump trucks in 2004. Furthermore, three dimensional static and eigenvalue analyses of the bridge were done using MSC/NASTRAN. This study investigates the structural performance on static and dynamic characteristics base on the field tests and the analyses, and gives a valuable data to evaluate structural performance for modern timber hybrid highway bridges.