In the process of deep-hole blasting, the quality of blasting stemming seriously affects the blasting effect, but the optimal stemming length is difficult to determine. In this paper, the movement process and length optimization of deep-hole blasting stemming were investigated. At first, the mechanical mechanism of stemming structure was theoretically analyzed, and the additional friction resistance of stemming structure caused by the compression of the blasting shock wave was considered. Then, a time-sharing piecewise solution method for the movement process of stemming structure based on the method of time-space discretization was proposed, which can reveal the distribution law of the decreasing friction resistance along the axial direction. Moreover, the movement law of stemming structure under the conditions of explosion pressure ranging from 0.2 to 1.2 GPa, duration of detonation gas ranging from 10 to 15 ms, sliding friction coefficients ranging from 0.02 to 0.06, borehole diameters ranging from 76 to 200 mm, and stemming length ranging from 1.6 to 3.0 m was studied. Results showed that explosion load, duration of detonation gas, sliding friction coefficients, borehole diameters and stemming length all have a great influence on the movement of stemming structure. Finally, aiming at the common stemming materials of rock debris in engineering blasting, the effects of rock mass properties, explosion load, and borehole diameters on the optimal stemming length have been discussed based on the optimization principle that allows the part of stemming structure to rush out of borehole. It is found that the optimal stemming length increases linearly with the logarithmic product of the explosion pressure and the borehole diameter by the statistical analysis of the optimal stemming length under different calculation conditions. In view of the above, a new method for calculating the optimal stemming length is proposed and its reliability has been verified preliminarily by field application.

在深孔爆破过程中，爆破堵塞质量严重影响爆破效果，但最佳堵塞长度难以确定。本文研究了深孔爆破堵塞的运动过程和长度优化。首先从理论上分析了堵塞结构的力学机理，考虑了爆破冲击波压缩引起的堵塞结构附加摩擦阻力。在此基础上，提出了一种基于时空离散化方法的分时分段求解阻塞结构运动过程的方法，该方法可以揭示摩擦阻力沿轴向递减的分布规律。. 此外，在爆炸压力0.2~1.2 GPa、爆气持续时间10~15 ms、滑动摩擦等条件下，堵塞结构的运动规律研究了系数范围为 0.02 至 0.06，钻孔直径范围为 76 至 200 毫米，以及堵塞长度范围为 1.6 至 3.0 米。结果表明，爆炸载荷、爆轰气体持续时间、滑动摩擦系数、钻孔直径和堵塞长度均对堵塞结构的运动有很大影响。最后，针对工程爆破中常见的岩屑堵截材料，基于允许部分堵截结构冲冲的优化原理，讨论了岩体性质、爆炸载荷、钻孔直径等因素对最佳堵截长度的影响。出井。通过对不同计算条件下最佳堵塞长度的统计分析，发现最佳堵塞长度随爆炸压力与井眼直径的对数乘积呈线性增长。有鉴于此，提出了一种计算最优词干长度的新方法，并通过现场应用初步验证了其可靠性。