中文摘要：

为提高高速铁路桥梁地震反应分析的精度,针对CRTSⅡ型板式无砟轨道体系的结构特点,提出考虑无砟轨道体系纵向约束效应的线桥一体化分析模型。以京沪高速铁路上自振特性不同的若干跨32m简支梁桥及大跨度连续梁桥为背景,采用线桥一体化模型与传统不考虑轨道约束的模型对比,分析轨道体系对高速铁路桥梁动力特性及地震反应的影响。结果表明：CRTSⅡ型轨道体系对高速铁路桥梁的地震反应影响与各跨桥梁动力特性的相对大小有关;不考虑轨道体系时,可能低估简支梁桥部分桥墩或连续梁桥制动墩的地震反应;受端刺纵向刚度的约束作用,连续梁两侧简支梁桥各墩的地震反应呈凸抛物线形分布。建议采用线桥一体化模型对CRTSⅡ型无砟轨道体系高速铁路桥梁进行地震反应分析。

英文摘要：

To improve the analysis accuracy of the seismic responses of high-speed railway bridges, an integrated track and bridge model considering the longitudinal restraint effect of the slab type ballastless track system CRTS II was proposed in accordance with the structural charac-teristics of the track system. The 32-m multi-span simply-supported girder bridges plus a long span continuous girder bridge having different natural vibration characteristics on Beijing-Shanghai High-Speed Railway were taken as the examples, the integrated track and bridge model was compared to the conventional model not considering the track restraint and the influences of the track system on the dynamic characteristics and seismic responses of the high-speed railway bridges were analyzed. The results of the analysis demonstrate that the influences of the track system CRTS H on the seismic responses of the high-speed railway bridges are associated with the relative scales of the dynamic characteristics of the different spans of the bridges. When the track system is not considered, the seismic responses of part of the piers of the simplysupported girder bridges or of the braking piers of the continuous girder bridge may be underestimated. Acted by the restraint of the longitudinal rigidity of the end spine, the seismic responses of the different piers of the simply-sup-ported girder bridges on both sides of the continuous girder bridge exhibit the convex parabola distribution. It is hence proposed that the seismic responses of the high-speed railway bridges with the track system should be analyzed, using the integrated track and bridge model.