Design of Restraint System for a Hybrid Girder Railway Bridge with Two Pylons of Different Heights
Featuring two pylons of different heights,the main bridge of a Jialingjiang River Bridge carrying a section of the Hanzhong-Bazhong-Nanchong High-speed Railway is a hybrid girder cable-stayed structure that are arranged in six spans of 45,55,58,335,58,and 49 m.A bespoke restraint system is developed to reduce the internal forces and displacement responses of the structure,as well to optimize the train travelling and rail track service conditions.Three longitudinal restraint systems and five transverse restraint systems were selected,and numerical analysis was carried out to compare the structural responses of the bridge with these restraint systems under static and seismic actions.As per the analysis,for a semi-floating system with a longitudinal damping restraint or with bearing displacement restraint,the static responses of the structure show minor difference and the seismic performance of the structure with damping restraint is better,while adopting the transverse damping restraint or stoppers to prevent girder falloff leads to better energy dissipation and limiting effect,but the damping restraint is not an effective seismic mitigation solution.In accordance with the seismic responses of these solutions as well as the demands on train travelling and rail track service conditions,a combined longitudinal restraint system is presented,with which the bridge remains a semi-floating system with bearing longitudinal displacement restraint at service stage and under the action of design seismic loads,and transform to be a semi-floating system with longitudinal damping restraint under rare earthquakes.The transverse restraint consists of permanent bearings and stoppers.The configuration and technical parameters were calculated to achieve the optimal performance target of the railway bridge.
high-speed railway bridgecable-stayed bridgepylons with different heightshybrid girderrestraint systembridge design
NETL
NSTL
万方数据
维普
