地面列车动荷载对下穿隧道影响的动力学响应分析

Analysis of Dynamic Response of Undercrossing Tunnels to Vibration Loads of Ground Trains

以青岛地铁下穿胶济铁路为研究背景,应用隧道结构的动力有限元数值分析方法,对列车动荷载作用下隧道结构-地层体系的动力响应进行三维数值模拟。分析了单列列车动荷载、两列列车动荷载同向及相向三种工况下,隧道结构-地层体系的应力及位移曲线。研究表明,在列车动荷载作用下,隧道结构-地层体系的动力响应呈现近似简谐波变化;从地表到隧道拱顶的动力响应不断衰减,且衰减速度从地表到隧道拱顶不断减小;两列列车动荷载作用下,隧道结构-地层体系的动力响应值较单列列车动荷载作用下的动力响应值有明显增加,但并未达到单列列车动荷载的两倍。

With Qingdao tunnels below Qingdao-Jinan high-speed railway as the research background,a three-dimensional numerical simulation was conducted on the dynamic response of the tunnel-stratum system to vibration loads of train by using dynamic finite element method of tunnel structures.The vertical displacements and stress of the tunnel-stratum system were analyzed under the vibration load of one train,under the vibration of two trains in the same direction and under the vibration of two trains in the opposite directions.Results show that the dynamic response curves of tunnel-stratum system under vibration load of train are approximate harmonic waves.The dynamic response of stratum decays continually and the decay rate is decreases from the surface to the arch crown of the tunnel.The dynamic response of the system under the action of loading induced by two trains is significantly increased compared with that induced by one train.However,the maximum dynamic response induced by two trains has not reached two times as much as that induced by one train.