为提高立井基岩段掘进爆破效率，改善破碎块度，采用理论分析和数值模拟相结合的方法，探讨深孔直眼掏槽大直径中心空孔的作用机理。理论研究表明：空孔为装药掏槽炮孔提供了一个与其相平行的辅助自由面和破碎岩石的补偿空间，加大了爆炸应力波的反射拉伸作用，空孔的存在造成了槽腔岩石中的拉应力集中，从而增大了岩石中的拉应力作用强度，引起槽腔中裂隙的进一步扩展延伸，使槽腔内岩石的破裂和破碎更充分。数值模拟结果进一步验证了大直径中心空孔所具有的应力叠加和反射拉伸作用。在此基础上，对空孔与装药孔间距的合理取值进行了理论分析计算，中心空孔应处在掏槽孔形成的爆破裂隙区之内，并选用较大的松动爆破作用指数进行设计。%In order to improve the blasting excavation efficiency of shaft in bedrock section and get better frag-mentation effect,the action mechanism of deep hole parallel cut with large diameter empty hole was explored by theo-retical analysis and numerical simulation. The theoretical research showed that empty hole provided a parallel auxilia-ry free surface and compensation space for charging cut hole,and increased reflection stretching function of explosive stress wave,and caused tensile stress concentration in rock mass,finally,oversize tensile stress strength in the rock made crack further expand in cut cavity,rock burst and broken more sufficiently. The numerical simulation results further verified tensile stress superposition and reflection effect of large diameter empty hole. Based on the reasonable value of distance between empty hole and charging hole from theoretical analysis and calculation,the empty hole should be located in the crack zone of cut hole and a larger loose blasting action index should be chosen during blas-ting parameters design.
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