喻梅 吕佳伟 贾宏宇 贾康 郑史雄 赵灿晖

摘   要：為了研究在近断层脉冲型地震作用下高速铁路桥梁-轨道系统的动力响应规律，针对高速铁路线上最常用的简支梁形式结构，以某8 × 32.7 m高速铁路简支箱梁桥为例. 建立了考虑简支梁与CRTS I型板式无砟轨道之间相互作用的桥梁-轨道模型，讨论了具有破裂前方脉冲、滑冲脉冲、无脉冲型近断层地震动对桥梁-轨道系统的影响及扣件阻力改变时桥梁-轨道系统动力响应的变化. 结果表明：三种脉冲类型地震动作用下钢轨的受力和变形规律保持一致，脉冲型地震动较无脉冲型地震动增加了约20%钢轨应力和位移. 相对于轨道系统，桥墩对脉冲类型更为敏感，在破裂前方脉冲和滑冲脉冲地震作用下，桥墩的墩顶最大位移比无脉冲地震动分别增大了106.6%和148.6%，墩底弯矩和剪力也有明显增大，在进行高速铁路桥梁抗震设计时应考虑脉冲类型对桥梁结构的影响. 扣件纵向阻力从5 kN/组增大到15 kN/组时，墩顶最大位移降低了10%，但钢轨应力和位移峰值约为原来的2倍.

关键词：近断层地震动;高速铁路;CRTS I型板式无砟轨道;脉冲效应;桥梁-轨道系统

中图分类号：U24                                 文献标志码：A

Response Analysis of High-speed Railway Bridge-rail

System Subjected to Near-fault Pulse-type Earthquake

YU Mei1，2，L Jiawei1，2，JIA Hongyu3，JIA Kang3，ZHENG Shixiong3，ZHAO Canhui3

（1. State Key Laboratory of Mountain Bridge and Tunnel Engineering（Chongqing Jiaotong University），Chongqing 400074，China;

2. Engineering Research Center of Bridge Structure and Material in the Mountainous Area of

Ministry of Education（Chongqing Jiaotong University），Chongqing 400074，China;

3. School of Civil Engineering，Southwest Jiaotong University，Chengdu 610031，China）

Abstract：To study the dynamic response law of high-speed railway bridge-rail system subjected to the action of near-fault impulse earthquake， an 8×32.7 m high-speed railway simply supported box girder bridge is taken as an example for the simple-supported beam form structure most commonly used on high-speed railway line. A bridge-rail model considering the interaction between simply supported beams and CRTS I type slab ballastless track is established. The effects of near-fault ground pulses with rupture front pulses，sliding pulses，and pulse-free near-fault on the bridge-rail system are discussed，as well as the changes of bridge-rail system dynamic response when fastener resistance changes. The results show that the stress and deformation rules of the track under the action of the three pulse types of ground motion are consistent. The pulse-type ground motion increases the track stress and displacement by about 20% when compared with the pulse-free ground motion. Compared with the track system，the pier is more sensitive to the type of pulse. Under the action of pulse and slip pulse before the rupture，the maximum displacement of the pier top is increased by 106.6% and 148.6%，respectively，when compared with the non-pulse ground motion. The bending moment of the pier bottom and the shear force are also increased significantly，and the impact of the pulse type on the bridge structure should be considered in the seismic design of high-speed railway bridges. When the longitudinal resistance of the fastener is increased from 5 kN/group to 15 kN/group，the maximum displacement of the pier top is reduced by 10%，but the peak stress and displacement of the track are about twice the original values.

Key words：near-fault ground motion;high-speed rail;CRTS I plate-type ballastless track;pulse effect;bridge and rail system

高速铁路是国家重要的交通基础设施，对我国经济发展具有重大的意义. 为了保证行车平顺性和旅客舒适性，也为了减小路基带来的沉降影响. 一般路段，高速铁路采用以桥带路的方式修建，从而使得桥梁总里程数不断增加，也导致了高速铁路……