高烈度区公路隧道横通道地震响应分析

Seismic response analysis of cross-passage of a highway tunnel in high intensity zone

双洞隧道主隧道与横通道交接部位是隧道抗震中的薄弱位置,以穿越高烈度区隧道为背景,采用MIDAS GTS-NX有限元分析软件,对在汶川地震动作用下的公路隧道横通道进行地震响应分析。在X方向和Y方向地震动荷载的共同作用下,通过对围岩和衬砌的计算结果研究,得出以下结论:隧道整体的最大相对位移主要发生在主隧道与横通道拱顶和连接处;衬砌相对位移随埋深增加而减小;隧道产生的横向变形更大;横通道边墙位置更容易受到剪切破坏,主隧道与横通道连接处拱脚的弯矩、剪力、最大主应力和最大剪应力最大,应重点采取设防措施。

0x09The interface between the main tunnel and the cross-passage of double-hole tunnel is the weak point in the seismic resistance of tunnels.In this study,MIDAS GTS-NX finite element analysis software was used to analyze the seismic response of the cross-passage of the highway tunnel under the action of Wenchuan ground motion for the tunnel passing through the high-intensity earthquake area.Under the combined action of the seismic loads in the X direction and Y direction,based on the calculation results of surrounding rock and lining,the following conclusions are drawn:The maximum relative displacement is at the vault of the joint between tunnels and the cross-passage;the relative displacement of lining decreases with the increase of burial depth;the transverse deformation of the tunnel is larger;the cross passage sidewalls are more vulnerable to shear failure;the bending moment,shear force,maximum principal stress and maximum shear stress of the arch foot at the interface between the main tunnel and the cross-passage are the largest,in which defensive measures should be taken into account with emphasis.