Rehabilitation and Simulation of Movable Bridge

Jiefang Bridge, the only rolling lift bascule bridge existing in China, was built in 1927. This paper presents the research of the rehabilitation design as well as the rolling operation restoration of this movable bridge. After structure inspection and evaluation, it is determined to begin with that numbers of severely corroded members must be replaced, the deck system retrofitted, and the rolling function restored in order to remain the original appearance of the bridge. Then, in order to accurately assess the mechanical performance of movable bridge, the kinematical simulation of the bascule span, during operation under multiple loading conditions and combinations including vehicle load, wind load, and inertial force is carefully studied based on a 3-D FE model. As the result of the research, the rehabilitation design is optimized, counterweight improved, and operation velocity and acceleration proposed. Presently, the rehabilitation of Jiefang Bridge has been finished and rolling operation successfully restored. Subsequent field testing and monitoring have proved that the theoretical analysis of the bridge is valid.