基于截面纤维模型的RPC箱型桥墩抗震性能分析

为探讨RPC箱型桥墩的延性抗震性能，采用截面纤维模型编制了压弯构件非线性分析程序，程序考虑了轴力的二阶效应，能模拟水平荷载不同的加载方向角，可对包括卸载过程在内的全过程受力性能进行分析.通过3个施加常轴力的RPC箱型桥墩水平反复加载试验结果与数值分析对比，验证了程序的准确性.在此基础上运用编制的程序分析了轴压比、纵筋率、截面长宽比和截面开孔率等参数在不同水平荷载加载方向时对RPC桥墩延性抗震性能的影响，得到了最不利水平加载方向与截面长宽比之间的关系.

Seismic Behavior Analysis of RPC Box Piers Based on the Fiber Element Model

To discuss the seismic behavior of RPC box piers, a nonlinear analysis program was compiled with the fiber element model by taking into account secondary effects of the axial force, in which the horizontal load under variable loading direction could be simulated and the whole loading process including the unloading could be analyzed. Based on the contrast analysis between cyclic loading test results of three RPC box piers samples under the invariable axial force and the calculation results, the precision of the program was proved. Factors affecting the seismic behavior of RPC box piers under the variable horizontal loading direction were analyzed, including axial compression ratio, reinforcement ratio, length-width ratio and opening ratio of the section, and the relationship between the most unfavorable loading direction and length-width ratio of the section was obtained.