不同抵抗线下地应力对漏斗爆破破碎的影响
Effect of in-situ stresses on fracturing performance of crater blasting under different resistance lines
邱贤阳 1沈文博 1张宗国 1陈辉 2史秀志1
作者信息
- 1. School of Resources and Safety Engineering,Central South University,Changsha 410083,China
- 2. School of Geological and Mining Engineering,Xinjiang University,Urumqi 830047,China
- 折叠
摘要
地下深井开采中,高地应力对岩石爆破破碎有重要影响,然而高应力条件下岩石爆破破岩的机理尚不清楚.本文采用模型实验和理论分析方法,研究地应力对漏斗爆破破碎的影响机制.首先采用混凝土试块开展围压加载下漏斗爆破试验,研究不同抵抗线下漏斗爆破破碎特征;然后建立了考虑炮孔壁应力集中的三维理论模型,进一步研究了地应力作用下漏斗爆破破裂机理.实验和理论结果表明:1)抵抗线较长时(超过6 cm),爆破漏斗体积随着加载围压的增加而减小;2)加载围压对爆破破碎程度的影响随着抵抗线减小(小于5 cm)由抑制作用转为促进作用;3)在高应力加载方向上的径向压裂受到抑制,反射拉伸压裂受到促进;反之,在低应力加载方向上的反射拉伸压受到抑制,而径向压裂受到促进.减小漏斗爆破抵抗线长度和增加孔间距是利用地应力促进岩石爆破破碎的最佳途径.
Abstract
In deep underground mining,high-stress condition plays a key role in rock blasting.However,the mechanism of rock breaking by blasting under high-stress conditions is still unclear.Therefore,crater blasting experiments and theoretical analyses were conducted to study the effect of in-situ stresses on rock fracturing.A 3D theoretical model considering stress concentration on the blasthole wall was conducted to further investigate the fracturing mechanism of crater blasting under in-situ stresses.The experimental and theoretical results allowed the following conclusions:1)Long resistance line(over 6 cm)results in a decrease crater volume along with increasing confining pressure;2)the influence of confining pressure on blasting gradually changes from negative restraining to positive promoting with decreasing resistance line(less than 5 cm);3)Radial fracturing was restrained and the reflected tensile fracturing was promoted in the direction of higher in-situ stress.While,radial fracturing was promoted and the reflected tensile fracturing was restrained in the direction of lower in-situ stress.Reducing resistance line of crater blasting and increasing between spacing hole are the best to take advantage of the in-situ stress to promote the rock fragmentation by blasting.
关键词
漏斗爆破/地应力/爆破破碎/抵抗线Key words
crater blasting/in-situ stresses/fracturing by blasting/resistance line引用本文复制引用
基金项目
National Natural Science Foundation of China(52004329)
National Key Research and Development Program of China(2022AB31023)
出版年
2023
NETL
NSTL
维普
万方数据