该文研究地震空间变异性对桥梁地震响应的影响。依据经过加速度幅值调整的EI-Centro地震波和空间相干模型,采用条件模拟算法-多变量线性预测(MLP)法合成继承选用记录物理特性的多点地震动,并通过大质量法将其施加到桥梁结构上。以一座高墩大跨曲线连续刚构桥为研究对象,分析比较地震动行波激励和完全空间变异性激励作用下的桥梁动力响应,研究结果表明:大跨度桥梁地震响应分析应考虑完全空间变异性的影响,有条件模拟技术可以应用于桥梁抗震分析。
The influence of the spatial variation of seismic ground motion on the seismic response of a continuous rigid frame bridge is studied. According to the EI-Centro wave adjusted with amplitude and a coherency model, the acceleration time histories of multiple supports inheriting the physical characteristics of the selected records are generated by utilizing the multivariate linear prediction (MLP) method, which falls into the conditional simulation algorithm. Then, acceleration time histories are exerted on the supports and the governing equations of motion of the bridge are solved by the large mass method. Finally, a long-span curved continuous rigid frame bridge with high piers subjected to earthquakes is taken as a case study in the consideration of the wave passage effect and full spatial variation. The numberical results show that the influence of full spatial variation should be considered in the seismic analysis of long-span bridges. In addition, the conditional simulation algorithm can be used in the seismic analysis of bridges.