深埋公路隧道在双向地震动作用下的最大动力反应分析

Comparative Analysis on Dynamic Responses of Deep-seated Highway Tunnel under Bidirectional Seismic Actions

为了解地震对深埋公路隧道的影响,以有限元软件MIDAS/GTS对武罐高速公路小石村隧道深埋段进行了单向、双向地震动作用和自重作用下的数值分析。地震动输入采用隧址区经过基线校正的50年10%超越概率的加速度时程。结果表明:双向地震作用对隧道结构的影响明显大于单向地震作用;隧道拱脚和拱顶处为地震作用下的最危险部位;纵向与竖向地震力的共同作用对隧道结构的影响最大。地震对深埋隧道的影响不可忽略。

The effect of earthquake actions on deep highway tunnel lining is investigated by numerical simulation using the finite element method（FEM） code MIDAS/GTS with the emphasis on the ground motions in unidirection,bidirections and on the gravity load.The acceleration time history obtained from the tunnel site with exceedance probability of 10% in 50 years is corrected with baseline before as input into simulation.The simulated results indicate that the response of tunnel lining under bidirectional seismic actions is bigger than those under unidirectional seismic action,where the arch springing and crown are the most dangerous positions under seismic forces.The combined actions of longitudinal and vertical directions will produce the biggest responses in tunnel lining.The impact of earthquake for deep tunnel can not be ignored.