Research on Seismic Isolation Schemes of High-speed Railway Continuous Girder Bridge Based on Life Cycle Cost

In the seismic design of long-span continuous beam bridges in high intensity seismic area, isolation devices are generally used to reduce the seismic response and economic losses of structures, and different arrangements of isolation measures often determine the seismic performance and initial cost of structures. In order to comprehensively evaluate the rationality of seismic isolation design of continuous girder bridge from its anti-seismic and economic performance, a high-speed railway continuous girder bridge in the high-intensity seismic area was taken as the background. A variety of seismic isolation schemes were designed to carry out seismic vulnerability analysis, and the economics of each scheme during the whole life of the bridge was discussed based on the minimum life cycle cost criterion. The results show that the whole bridge could use the hyperbolic spherical isolation bearing and the viscous damper to minimize the earthquake loss during the whole life cycle, but the initial cost of the bridge was too high due to the cost of isolation measures, which led to the poor economy of this scheme. While, equipping the whole bridge with hyperboloid spherical isolation bearings and side piers with viscous dampers was the optimal scheme in the seismic isolation design of the bridge, which met the requirements of seismic fortification, greatly reduced the initial cost and achieved balance between the cost of structural isolation measures and expected loss of the bridge. Facing with the problem that the current bridge seismic isolation scheme designs were mainly considering the seismic performance of bridge but ignoring its economic benefits, the research method of bridge seismic isolation scheme presented in this paper realized the double objective evaluation of structural seismic performance and economic benefit, which would provide a new idea for stakeholders to make reasonable decision on bridge seismic isolation scheme. Copyright ©2020 Advanced Engineering Sciences. All rights reserved.