装药爆炸下地下拱形结构变形及破坏特征分析

Deformation and damage characteristics analysis of underground arch structure subjected to subsurface blast

地下拱形结构侵彻爆炸下涉及许多复杂的物理过程,即装药的爆炸、弹坑的形成、冲击波的传播、应力波在岩石介质中的传播以及岩石与结构的相互作用。为了解决上述复杂问题,利用非线性动力有限元软件LS-DYNA对常规武器侵彻爆炸作用下地下拱形结构的动力响应展开研究。通过数值模拟可较直观地了解应力波的传播过程,及爆炸应力波在拱形结构物中传播及与周围围岩的相互作用。对爆炸应力波作用下拱形结构的变形和破坏特点进行了分析。数值计算结果表明,在爆炸应力波作用下钢筋混凝土结构内侧受反射拉伸波作用产生震塌破坏,加大药量时结构的震塌破坏程度加重,大约在距拱中心线1/4处产生应力集中,形成塑性铰。可为工程设计、改造加固及战时快速抢修提供有益的参考。

The subsurface blast effect on underground structures involves many complicated physical process, namely the explosion of the charge, the formation of the crater, propagation of the shock wave and the stress wave in the rock, rock-structure interaction, and the response of the arch structure. To handle this complex problem, non-linear dynamic FEM LS-DYNA was employed to research the damage effect of the underground arch structure under the penetration explosion. A better understanding of the propagation of the explosion wave and the mutual action between the rock mass and the arch structure was obtained by the numerical simulation. The deformation and the damage characteristics of the arch structure are analyzed. Under two kinds of explosive charge, the spalling failure of the inner-side of the concrete arch structure was generated due to the reflecting extension wave. There are stress concentrations approximately at the 1/4 from the mid-center of the arch. The parameters obtained from the numerical calculation can be made a useful reference to the engineering design, fortification and rapid repair in war time.