喀斯特溶洞对爆破施工影响的数值模拟研究

Numerical Simulation Study on the Influence of Karst Cave on Blasting Construction

喀斯特岩溶地质对爆破应力波的传播有叠加效应。用ANSYS/LS-DYNA建立了有无溶洞工况下的爆破数值仿真模型,得到了溶洞对爆炸应力波的不同时间下的传播过程,分析了溶洞周围爆破振速与位移变化曲线,并通过贵州铜仁某边坡爆破工程实际相互验证。结果表明:爆破振动速度经过溶洞后有叠加放大作用,溶洞的存在能够在一定程度上减小爆破对岩体的位移扰动,对溶洞周围的岩体起到二次挤压破碎的作用。

Karst geology has a superposition effect on propagation of blasting stress wave. The numerical simulation models of blasting under the conditions of karst cave or non-cave were established by ANSYS/LS-DYNA, which obtained blasting stress wave propagation under different time in karst cave, Then, the blasting vibration velocity and displacement curves surrounding caves were analyzed, and could be mutually authenticated in a slope blasting engineering in Tongren of Guizhou. The results showed that the blasting vibration velocity had superposition amplification effect after passing the cave. Thus, the existence of the cave could decrease the disturbance of blasting on rock mass displacement in some extent, which played the role of secondary crushing to the rock surrounding cave.