爆炸冲击波作用下围岩与被覆结构的动力相互作用

摘要

The dynamic interaction between the surrounding rock and the initial supporting structure is essential for determining the load of the underground structure and designing the supporting structure.Using the nonlinear dynamic finite element procedure of ANSYS/LS-DYNA and the fluid-solid coupling algorithm,we simulated the underground arch structures with different spans subjected to the shock wave produced by an explosion perpendicular to the vault.Based on the wave theory we also analyzed the dynamic interaction force between the surrounding rock and the supporting structure and the applicability of the dynamic load equation,and obtained the variation of the maximum interaction.The results show that,at a perpendicular explosion that occurs 1 ～25 m away from the vault,the structures with 14～25 m spans experience partial failure on the vault while the concrete structure of the whole structure forms overall cracks.The maximum dynamic interaction force is observed when the explosion occurs at a distance 4 m.Our study can serve as a basis in determining the maximum load for the design of the surrounding rock and the underground structure.%爆炸作用下围岩与被覆结构的动力相互作用对于合理确定防护结构荷载、科学设计被覆结构具有重要意义.运用ANSYS/LS-DYNA非线性显式动力有限元程序和流-固耦合算法,对垂直爆炸作用下不同爆距、不同跨度的地下结构与围岩的动力相互作用进行了数值模拟,应用波动理论进行了动力相互作用力分析,讨论了相互作用动载计算公式在岩石结构中的适用性,得到了围岩与被覆结构的最大相互作用力变化规律.研究结果表明:在距拱顶1～25 m垂直爆炸作用下,14～25 m跨地下结构都发生了拱顶局部破坏,整个拱的混凝土均会产生震动裂缝;当爆距为4m时,围岩与结构的动力耦合作用最大,可以作为确定最大荷载的依据.