大空孔复式筒形直眼掏槽力学机制与数值模拟分析

Mechanical mechanism and numerical simulation analysis of compound barrel parallel cut with big cavity

为了解决矿山硬岩巷道爆破开挖存在炸药单耗高、炮眼利用率低和掘进深度短等问题,应用理论分析、数值模拟与现场实践相结合的方法,提出大空孔复式筒形直眼掏槽方式。根据静力学理论,简化掏槽区域岩体只受爆生气体的准静态膨胀作用,并在复式筒形直眼掏槽腔体成形力学机制的基础上,分析大空孔形式下空腔形成的物理力学过程;采用LS-DYNA软件建立数值模型,基于材料参数和状态方程,仿真分析大空孔复式筒形直眼掏槽槽腔有效应力的传播机理;依据巷道尺寸及爆破参数,进行大空孔复式筒形掏槽掘进现场试验。试验结果表明:炮眼利用率提高到89.0%,掘进深度达到2.8 m,炸药单耗降低到3.16kg/m^3,充分证明大空孔复式筒形直眼掏槽方式的可行性。

In order to solve the problems of high unit consumption of explosive,low utilization rate of blast hole and short excavation depth in the blasting excavation of hard rock roadway in mine,a way of compound barrel parallel cut with big cavity was put forward by using the combined methods of theoretical analysis,numerical simulation and field practice.It was simplified that the rock mass in the cut area was only affected by the quasi-static expansion effect of explosive gas according to the mechanics theory,and the physical and mechanical processes of cavity formation under the form of big cavity were analyzed on the basis of the mechanical mechanism of cavity formation in the compound barrel parallel cut.A numerical model was established by using the LS-DYNA software,and the simulation analysis on the propagation mechanism of effective stress in the cavity of compound barrel parallel cut with big cavity was carried out based on the material parameters and state equations.The field tests of excavation by the compound barrel parallel cut with big cavity were conducted according to the roadway size and blasting parameters.The results showed that the utilization rate of blast hole increased to 89.0%,the excavation depth reached 2.8 m,and the unit consumption of explosive reduced to 3.16 kg/m 3,which fully proved the feasibility of the compound barrel parallel cut with big cavity.