地震诱发沙土液化对高速铁路车桥系统动力响应的影响分析  

Effects of earthquake induced sand liquefaction on dynamic response of high-speed railway train-bridge system

作　　者：雷虎军 陈奕涵 朱广平 LEI Hujun;CHEN Yihan;ZHU Guangping(College of Civil Engineering,Fujian Engineering College,Fuzhou 350118,China)

机构地区：[1]福建工程学院土木工程学院,福州350118

出　　处：《振动与冲击》2022年第13期195-203,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51878173);福建省自然科学基金项目(2020J01883)。

摘　　要：为研究地震诱发沙土液化对高速铁路车桥系统动力响应的影响,以某(88+168+88)m预应力混凝土连续刚构桥为例,采用Winkler地基梁模拟群桩基础并通过“m法”考虑桩土相互作用,同时引入液化土力学指标折减系数Ψ模拟砂土液化,建立了带有群桩基础的全桥有限元模型。在此基础上,基于TTBSAS程序系统研究了液化深度和液化程度对车桥系统动力响应的影响并分析了桥上列车的行车安全性。结果表明:桥梁横向位移随液化深度的增加会显著增大,而横向加速度的变化规律还与列车车速有关;行车安全性指标随液化深度的增加均增大,但增幅小于桥梁位移,且液化深度对桥上列车行车安全性的影响会随车速的增大逐渐减弱;液化程度对车桥系统动力响应的影响与液化深度基本一致;不考虑场地沙土液化会高估列车过桥的行车安全性,其中:对于脱轨系数指标,考虑与不考虑沙土液化时的安全车速阈值分别为275 km/h和300 km/h,对于轮对横向水平力指标,分别为200 km/h和225 km/h。研究成果可为液化场地高速铁路桥梁的行车安全评价提供参考。Here,to study effects of earthquake induced sand liquefaction on dynamic response of high-speed railway train-bridge system(TBS),taking a(88+168+88)m prestressed concrete continuous rigid frame bridge as an example,Winkler foundation beam was used to simulate pile group foundation,pile-soil interaction was considered with“m method”,and the liquefied soil mechanical index reduction coefficientΨwas introduced to simulate sand liquefaction.The finite element model of the whole bridge with pile group foundation was established.Then,based on TTBSAS program,effects of liquefaction depth and degree on dynamic response of TBS were systematically studied,and train driving safety on bridge was analyzed.The results showed that bridge lateral displacement can increase significantly with increase in liquefaction depth,while variation law of bridge lateral acceleration is also related to train speed;the driving safety index increases with increase in liquefaction depth,but its increase range is less than that of bridge displacement,and effects of liquefaction depth on train driving safety on bridge can gradually weaken with increase in train speed;effects of liquefaction degree on dynamic response of TBS is basically consistent to those of liquefaction depth;the train driving safety during it passing through bridge can be overestimated if not considering site sand liquefaction;for the derailment coefficient index,safe speed thresholds considering and not considering sand liquefaction are 275 km/h and 300 km/h,respectively,for the lateral horizontal force index of wheel set,they are 200 km/h and 225 km/h,respectively;the study results can provide a reference for driving safety evaluation of high-speed railway bridges in liquefaction site.

关 键 词：高速铁路 车桥系统 砂土液化 动力响应 安全车速 

分 类 号：U24[交通运输工程—道路与铁道工程]