钻孔间距对岩石静态破碎效果影响的数值模拟研究

Numerical Simulation of Rock Static Breakage with Different Drill HoleSpacings

运用岩石破裂系统RFPA^(2D),基于静态破碎膨胀力增长曲线,模拟不同间距条件下双孔模型的破裂过程,探究不同钻孔间距在静态破碎作用下的岩石破裂贯通过程的声发射规律、钻孔间应力分布变化,研究不同间距钻孔之间裂纹生长、发育和破裂机制.研究结果表明:岩石破裂阶段产生少量的声发射事件,声发射累计能量较多,而裂纹贯通阶段正好相反;随着预制孔间距的加大,开裂破碎需要更多的载荷步,裂纹贯通阶段的声发射数量分布趋于平缓,同时裂纹发展方向不再沿着最短路径延伸且会产生较多的岩石碎块,运用孔间最小主应力曲线对裂纹扩展过程进行解释,以为不同工程条件下合理布置岩石钻孔提供新的研究方法和途径.

Using the rock fracture system RFPA2D,and based on the static fracture expansion force growth curve,the rupture process of two holes at different spacings was simulated to explore the acoustic emission of rock breakage,connection,and penetration processes with different drilling spacings under static crushing,and the distribution of stresses between drill holes.The crack growth and development mechanism between boreholes at different distances were studied.The analysis shows that there are fewer acoustic emission events at the rock rupture stage,but there is more cumulative energy of acoustic emission; with the increase of the spacing of the prefabricated holes,more load steps are needed for cracking and breaking.The distribution of acoustic emission at the stage of crack penetration tends to be gentle,and the direction of the crack development no longer extends along the shortest path,and more rock fragments are produced.The crack propagation process is explained by the minimum main stress curve between the holes.It also provides a new research means and way of studying different hole spacing,hole radius and reasonable arrangement of rock materials..