轴向不耦合装药结构形式优化仿真研究

为了改变某隧道平导爆破效果差、爆炸能量利用率低的现状,采用ANSYS/LS-DYNA模拟不同轴向不耦合装药结构形式对爆破效果的影响,优化装药结构,以期达到增强爆破效果,降低粉尘量和岩石大块率的目的。合理的选择数值模拟中的材料模型和算法,是高效模拟分析轴向不耦合装药结构爆破的关键,因此采用ALE算法对孔口空气填塞不耦合,孔口炮泥填塞、上部空气间隔不耦合,孔口水介质填塞、底部水介质间隔不耦合,孔口炮泥填塞、上部水介质间隔不耦合,孔口水介质填塞、中部水介质间隔不耦合和孔口炮泥填塞与中、上部水介质间隔不耦合的装药结构进行数值模拟,并以爆炸应力波云图和最大拉应力来评价炸药爆破效果。数值模拟结果表明:水介质可以降低炮孔壁附近岩石的压力。装药长度1.25m时,孔口炮泥填塞、上部空气间隔不耦合装药结构较孔口空气填塞不耦合装药结构,能提高爆炸能量的利用率;孔口水介质填塞、底部水介质间隔不耦合装药结构和孔口炮泥填塞、上部水介质间隔不耦合装药结构,爆炸能量利用率基本相同;孔口水介质填塞、中部水介质间隔不耦合装药结构的炸药爆炸能量利用率较其余5种装药结构都大,能提高爆炸应力波对岩石的作用,使得爆炸应力波更加均匀作用于岩体,降低大块率产生。此数值模拟结果可为现场爆破方案设计与实施提供依据。

Simulation study of optimization on the axial uncoupling charging structure

In order to change the low level blasting effect and the blasting energy low utilization rate of a tunnel,it is simulated that effect of different axial uncoupled structures on blasting by ANSYS/LS-DYNA,in order to achieve the goal of improving the blasting effect and reducing the amount of gun dust and rock mass rate that optimized the axial uncoupling charge structure.Choosing a reasonable material model and algorithm for numerical simulation is the key to efficiently simulate and analyze the blasting of axial uncoupled charge structures.So it is studied that hole air stuffing,mud plugging and upper air interval,water medium filling and bottom water medium interval,mud plugging and upper water medium interval,water medium filling and middle water medium interval,mud plugging and medium and upper water medium interval,uncoupled charge structure by ALE,and the blasting effect of explosives is evaluated by the explosion stress wavenephogram and the maximum tensile stress.The numerical simulation results show that the water medium can reduce the rock pressure near the borehole wall.When the charge length is 1.25 m,compared with hole air stuffing,the mud plugging and upper air interval can improve the utilization rate of explosive energy.The utilization rate of water medium filling and bottom water medium interval is basically the same as mud plugging and upper water medium interval.The utilization rate of explosive energy of water medium filling and middle water medium interval is greater than that of the other five kinds of explosive charge structure,increases the effect of explosion stress wave on rock,makes the explosion stress wave more homogeneous and affects the rock mass,reduces rock mass rate.The numerical simulation results provide the basis for the design and implementation of blasting scheme.