中文摘要：

为深入了解隧道在地震过程中的破坏机理及其洞口段的动力响应规律，以具有间距和错距的实际隧道为原型，建立数值计算模型并进行了计算分析．计算结果表明：1）对于双洞错距隧道，隧道洞口段衬砌横断面的相对位移、最大Mises应力和加速度幅值受地震荷载激振方向的影响较大．即使在同一方向地震荷载作用下，左、右洞洞口段的动态响应仍有较大区别，而隧道洞身段的动态响应相近．2）当地震荷载在某一方向或其他组合方向上施加后，衬砌卜将同时存在空间上任意方向的加速度矢量，且衬砌加速度幅值在洞口处具有放大现象．

英文摘要：

To understand the tunnels＇ damage mechanism and the law of the dynamic response in the portal section, this paper establishes a numerical model based on the actual tunnel with spaces and staggered space and had the calculation. The calculating results show that for two parallel tunnels with staggered space, the relative displacement, maximum Mises stress and the amplitude of acceleration in the tunnel liner cross-section of portal section are affected by the vibration direction of seismic load. The dynamic responses of portal section still have significant differences between the left and the right tunnels even in the same vibration direction; however, the dynamic responses of the tunnel trunk section are close. When the seismic load is acted on one direction or the other combination direction, acceleration vector in any direction of space will exist simuhaneously on the lining, and the lining acceleration amplitude on the tunnel entrance is magnified.