[Article Information]

Influence of Rock Mass Structure on Bench Blasting Effect



FU Peng




Abstract


Abstract: As a discontinuous and anisotropic heterogeneous structure,rock mass is randomly distributed with joints,cracks,faults and other structural planes. The existence of structural planes has an important influence on blasting effect. In order to explore the influence of the angles and locations of structural planes on bench blasting effect, LS-Dyna numerical simulation and field experiments were conducted based on Beskuduk open pit coal mine. The numerical simulation results show that when the dip of the structural plane is less than 30 degrees,the peak stress is less affected. When the dip of the structural plane is greater than 30 degrees,the initial peak value of the explosion stress wave increases with the increase of the angle. In addition,the position of a weak interlayer in a bench affects the energy release. Compared to the situation that the weak interlayers are located in the upper area of the bench,the blasting effect when the weak interlayers are located in the middle and lower areas,the energy release is more obvious with a worse blasting effect,therefore a specific blast method is needed to solve the problem. The field practice shows that with the increase of the structural plane angle,the boulder yield presents a decreasing trend. For the situation that the weak interlayers are located in the middle and lower part of the bench,the method of increasing the subdrilling to 0. 5 m and adding 3 ~ 5 m depth to the inclined holes can effectively reduce the boulder yield,improve the blasting effect and the shovel loading efficiency.



Key words: structural plane; blasting vibration; bench blasting; numerical simulation





Chinese Information


标题: 岩体结构面对台阶爆破效果影响研究



作者: 傅 鹏



摘要: 岩体作为一种不连续的、各向异性的非均质结构体,随机分布有节理、裂隙和断层等结构面,各类 结构面的存在对爆破效果具有重要的影响。为探究岩体结构面对台阶爆破效果的影响,以别斯库都克露天 煤矿为研究对象,分别采用 LS-Dyna 数值模拟与现场实验研究结构面角度和位置对台阶爆破效果的影响。 数值模拟结果表明: 当结构面倾角小于 30°时,应力峰值受结构面倾角影响程度较低; 当结构面夹角大于 30° 时,爆炸应力波的初始峰值随夹角的增大而增大。在台阶不同位置存在软弱夹层时,台阶爆破泄能结果差异 较大。当软弱夹层位于台阶上部区域,爆破效果较好。当软弱夹层位于台阶中部和下部区域时,台阶爆破泄 能较为明显,导致爆破效果较差,需要制定专门的爆破方案进行处置。现场实践表明: 随结构面倾角的增加, 爆破后爆堆的大块率呈减小趋势。针对现场存在的软弱夹层位于中下部情况,通过采用加大炮孔超深 0. 5 m,并在软弱夹层下部岩体增加 3 ~ 5 m 深斜孔的方法,能有效降低大块率,改善爆破效果,提高铲装效 率。



关键词: 结构面; 爆破振动; 台阶爆破; 数值模拟



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