城市高架桥塌落冲击地铁隧道结构的动态响应及防护技术

Dynamic response and protection technology research on metro tunnels under collapse vibration of city viaduct

利用ANSYS/LS-DYNA有限元软件对城市高架桥塌落振动及其对地铁隧道结构的影响进行了系统研究,建立了适于描述桥体塌落冲击作用下地铁隧道结构动力响应的三维有限元计算模型。通过比较有、无防护条件下桥体塌落冲击隧道结构动力响应过程,得到了不同工况下典型质点单元三向振动速度及应力时程曲线变化规律。研究结果表明,与无防护措施条件下桥体塌落冲击隧道结构相比,以"钢板-橡胶轮胎"为主要形式的复合防护结构使隧道所受的振动速度、压应力和拉应力最大值分别下降了98.7%、95.6%及94.4%。实测数据与数值计算结果具有良好的一致性,隧道结构所承受的振动速度低于地铁管理部门提出的安全阈值要求,综合防护体系设计达到了预期效果。

; The collapse vibration performance laws of city viaducts to metro tunnels were obtained by using ANSYS/LS-DYNA software. The calculation model of collapse bridge impact to the underground tunnels of cities was established. Dynamic response of a metro tunnel including three-direction vibration velocity and stress process of typical units was also obtained. The results show that as a main form of composite protective structure consisting of a steel plate- rubber tires system can make maximum of metro tunnel vibration velocity, compressive stress and tensile stress were decreased by 98. 7% , 95. 6% , and 94. 4% compared with the absence of protective measures. It has shown excellent agreement between measured data and simulation results. Metro tunnel borne vibration speed is lower than the administration proposed safety threshold requirement and the design of comprehensive protection system achieves the expected result.