定向卸压爆破试验研究与数值计算

对定向卸压爆破进行了砂浆爆破模型试验，对护壁面、临空面、底部3个方向进行了超动态应变测试，并通过ANSYS/LS-DYNA有限元软件对该试验进行3维数值计算，对距离炸药相同距离的临空面、护壁面、底部3个方向岩体内压力值与试验结果进行了对比，分析了压力的分布规律，明确了护壁材料与底部间隔空气柱对炮孔的卸压作用。结果表明炮孔临空面一侧出现了明显的应力集中现象，距炸药中心相同距离，护壁面比临空面的压力平均降低率达到了26%，PVCU隔振材料起到了很好的定向保护作用。炮孔底部空气柱对炮孔压力影响明显，具有较强的卸压功能，数值模拟结果与模型试验结果有很好的一致性。

Model Test and Numerical Simulation for Directional Pressure Relief Blasting

The cement mortar model tests on the directional pressure relief blasting were carried out to make ultra dynamic strain tests from three directions of protecting borehole wall，free-face wall and bottom wall.Three-dimensional numerical simulation and numerical calculation of tests were made by using ANSYS/LS-DYNA software.The pressure value and the tests results with the same distance from explosives to borehole wall，free-face wall and underside wall were compared，the distribution of pressure was analyzed and the blast hole pressure relief effect by protecting borehole wall materials and bottom interval air column is explicated.The present results indicate that there is an obvious stress concentration phenomenon at one side of the free-face wall，is the same distance apart from the explosive center.The pressure at protecting borehole wall is lowered by the average 26% than that of the free-face wall，where the vibration isolation material，PVCU，plays a good directional protection.Air column at blast-hole greatly affects the pressure，and has a strong pressure relief function.The simulation results were in good agreement with the experimental date.