Study on Displacement-based Seismic Design Procedures of Rocking Bridge Piers With Posttensioned Tendons
Wang Junwen1,2 Zhuang Weiguang1,2 Li Jianzhong3
1.School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang, Hebei Province ,050043, China； 2. Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education, Shijiazhuang Tiedao University, Hebei Province ,050043, China； 3. Department of Bridge Engineering, Tongji University, Shanghai, 200092, China
Abstract：Based on performance-based design philosophy, a displacement-based seismic design procedure for rocking bridge piers with post tensioning tendons is developed. In this design procedure, the level of piers damage is determined on the basis of earthquake fortification level, target displacement of piers is estimated considering the effect of deformation of the interface region where piers connect to footings; with inelastic response spectrum, the displacement demand under the earthquake is calculated. Energy dissipation bars or additional external dissipation devices in the piers-to-foundation critical interface region are used to dissipate earthquake energy by yielding, unbonded post-tensioning tendons are used to provide the shear resistance through friction developed at the pier-to-footings interface by the post-tensioning force, the initial tension of tendons is designed in details to maintain stress in tendons in the elastic range, and negligible residual displacements of piers are expected. The reliability of this design procedure is assessed by comparison with existing design procedures. The results of studies show that, compared with existing design procedures, the proposed design procedure gives results that is more consistent with the results of nonlinear time-history analysis.
2014, Vol. 33 
