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随着我国高速公路网的逐渐完善,山岭隧道建造的数量越来越多,修建隧道中遇到的不良地质情况也越来越复杂,尤其是隧道穿越地层富含瓦斯时,给隧道的修建工作带来了挑战。以成都洛带古镇隧道为工程案例,采用显示动力学分析软件AUTODYN在考虑衬砌结构和空气的流固耦合作用下建立数值模型,对隧道衬砌结构在由瓦斯爆炸产生的冲击荷载作用下的速度和位移响应及衬砌结构受损破坏过程进行了计算分析,数值模型中以TNT模拟瓦斯。计算结果表明,在不同TNT当量作用下,超压峰值以爆心在仰拱地面上的投影点为中心向四周衰减;超压峰值和炸药量成正比,爆炸冲击波在衬砌结构的纵向和径向运动过程不尽相同,衬砌各部位的受损程度也不尽相同,最终是局部破坏导致衬砌结构的整体破坏,使得衬砌结构失去支护承载能力。
With the gradual improvement of the expressway network in our country, more and more mountain tunnels are built, and the adverse geological conditions encountered in the construction of tunnels are also becoming more and more complicated. In particular, when the tunnels cross the strata and are rich in gas, the tunnel construction work Challenging. Taking Luodai ancient town tunnel in Chengdu as an example, a dynamic numerical simulation software AUTODYN was used to establish a numerical model considering the fluid-structure interaction between the lining structure and the air. The tunnel tunnel lining structure under the impact load of gas explosion Displacement response and the damage process of lining structure were calculated and analyzed. In the numerical model, TNT was used to simulate gas. The results show that under different TNT equivalence, the overpressure peak decays around the projection point of the ground on the inverted arch ground. The overpressure peak is proportional to the amount of explosive. The longitudinal and radial movement of the blast shock wave in the lining structure The process is not the same, the degree of damage of various parts of the lining are not the same, and ultimately the local damage caused by the overall damage to the lining structure, making the lining structure loses the support carrying capacity.