空气间隙不耦合爆破法开采大规格块石方法研究

Study on the Air Gap Decoupling Blast Method in Large Block Stone Mining

通过对两种径向和轴向空气间隙不耦合装药爆破法的分析,分别确定其包含空气间隙不耦合系数的岩石炮孔壁初始压力表达式;在压碎圈半径不大于炮孔半径,炮孔壁初始压力不大于极限动态抗压强度时,得出两种空气间隙不耦合系数满足的条件关系。给定岩石、炸药和规格块石开采情况,计算得出两种装药方式最小不耦合系数,以及相应的单孔用药量、炮孔直径、最小抵抗线等参数。最后结合工程实例进一步优化爆破参数,得出轴向空气间隙不耦合爆破法在开采5t以上大规格块石方面最有优势,其开采率可达18%~19%。

In this paper,the initial pressure expression of the hole wall in the rock with the gap was determined by the analysis of the two kinds of radial and axial air gap decoupling blast methods. When the radius of the crushing circle was not greater than that of the hole radius,the initial pressure of the hole wall was not greater than ultimate dynamic compressive strength,the conditions for the two kinds of air gap decoupling coefficients were obtained. With given rock,explosive and rock mining situation,the minimum decoupling coefficient of two kinds of charging methods were calculated,and it's explosive amount in one single hole,the diameter of the hole,the minimum resistance line and other parameters were obtained too. Finally,combined with the engineering example to further optimize the blasting parameters,it was concluded that the axial air gap decoupling blast method had great advantages in the mining of 5t above large block stone,and it's mining rate was up to 18% ~ 19%.