Structural Performance of Large Timber King Post Truss Highway Bridge

The bridge (Karikobozu Bridge) objected in this study is glulam timber king post truss highway bridge constructed in 2003, and is largest scale in the world. The main design geometry is as, span length: 48.2 m, truss height: 24.1 m, clear width: 7.0 m, and stress glulam slab: 0.33 m. The bridge length is 140 m (truss: 25m + truss: 50m + truss: 50m + girder: 15m). For the purpose such as (1) inspection of design factors and safety, (2) evaluation of structural rigidity, (3) investigation of environmental vibration problems under traffic loading and (4) store of initial data for maintenance, the static and dynamic field tests of the bridge with two dump trucks were done in July of 2003. The structural characteristics and performances on static and dynamic behaviours were investigated in the terms such as deflection, response vibration, dynamic characteristics, dynamic increment factor and vibration serviceability. Furthermore, three dimensional static and eigenvalue analyses of the bridge were also done by FEM of MSC/NASTRAN. This study investigates the structural characteristics and performances based on the field tests and the analyses.