跨断层桥梁非一致激励输入模型适用性研究
Applicability Research on Multi-support Excitation Input Model of Bridges Crossing Fault

为研究适用于跨断层桥梁的地震动输入分析模型，以1座跨断层桥梁为例，分别计算了非一致激励位移输入模型和大质量法加速度输入模型的地震响应，探讨了2种输入模型的适用性及模型误差产生原因。结果表明：位移输入模型可考虑永久地面位移对结构地震响应的影响，能够真实反映跨断层桥梁在地面运动结束之后桥墩具有的残余内力和变形，适用于跨断层桥梁非一致激励地震响应分析，而大质量法加速度输入模型对此无法考虑，可能导致不合理也是不安全的计算结果；在运用通用有限元计算软件进行加速度输入模型多点激励分析时，应首先核查与拟输入加速度时程对应的位移时程是否存在永久地面位移，若存在永久地面位移，则建议改为位移输入模型进行计算，否则将可能得到失真的计算结果。
In order to study the applicable ground motion input analysis model for bridge crossing fault (BCF), the seismic response of multi？？support excitation displacement input model and acceleration input model of large mass method were calculated respectively with a BCF as an example, and the applicability of two models and the reasons of model error were discussed. The results show that displacement input model can consider the influence of permanent ground displacement on seismic response of structures, and the residual internal force and deformation of bridge pier of BCF after ground motion can be truly reflected. The displacement input model is suitable for the multi？？support excitation seismic response analysis of BCF. However, without considering the residual internal force and deformation, the calculation results by acceleration input model of large mass method can be unreasonable and unsafe. When using the general finite element software to analyze multi？？support excitation of acceleration input model, whether there is a permanent ground displacement in the displacement time history corresponding to the input acceleration time history should be checked firstly. If there is permanent ground displacement, it is recommended to use the displacement input model to calculate, otherwise it will be possible to obtain the distortion calculation results