不同应力条件下组合孔爆破破岩规律数值模拟研究  

Numerical Simulation Research on Rock Breaking Law of Combined Hole Blasting under Different Stress Conditions

作　　者：杨海涛 李二宝[1,3] 仪海豹 戴勇 YANG Hai-tao;LI Er-bao;YI Hai-bao;DAI Yong(Sinosteel Maanshan Institute of Mining Research Co.,Ltd.,Maanshan 243000,China;State Key Laboratory of Safety and Health for Metal Mines,Maanshan 243000,China;Maanshan Institute of Mining Research Blasting Engineering Co.,Ltd.,Maanshan 243000,China;School of Resources and Safety Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中钢集团马鞍山矿山研究总院股份有限公司,马鞍山243000 [2]金属矿山安全与健康国家重点实验室,马鞍山243000 [3]马鞍山矿山研究院爆破工程有限责任公司,马鞍山243000 [4]中南大学资源与安全工程学院,长沙410083

出　　处：《爆破》2021年第2期88-94,共7页Blasting

基　　金：安徽省重点研究和开发计划(编号:201904a07020038);国家重点研发计划(编号:2017YFC0602902)。

摘　　要：深部矿山爆破开采不可避免的受到初始地应力的作用,为探究高地应力下组合孔破岩规律,对初始应力与组合孔爆炸应力联合破岩机理进行分析,开展不同应力作用下组合孔爆破破岩数值模拟研究。结果表明:初始应力对爆破作用的抑制或者促进取决于其与岩石的弹性极限的对比关系,当初始应力小于岩石的弹性极限时,表现为抑制作用,当初始应力大于岩石的弹性极限时,表现为促进作用。加载不同初始应力时(岩石峰值应力为90.58 MPa),组合孔破坏失效单元个数、裂隙扩展长度均符合“先减小后增大”的趋势,且拐点处应力值为25 MPa,为岩石峰值应力的27.6%,与岩石应力-应变全过程曲线中弹性极限应力值一致;提取分析测点处的有效应力及振动速度可知,随着初始应力的增强(20~50 MPa),测点处耦合应力呈线性增大趋势,表明初始应力与爆炸应力耦合作用下,初始应力占主导作用;组合孔方案中超前致裂孔爆破为前排孔创造新的自由面,监测点处的振动速度监测情况表明,组合孔爆破方案具有很好的减震作用。Blasting in deep mines is inevitably affected by initial ground stress.In order to explore the rock breaking law of combined holes under high ground stress,the combined rock breaking mechanism of initial stress and combined hole explosion stress was analyzed,and the numerical simulation research on rock fragmentation by combined hole blasting under different stresses was carried out.The results show that the suppression or promotion of the initial stress on the blasting effect depends on the comparison between the initial stress and elastic limit of the rock.When the initial stress is less than the elastic limit of the rock,the effect is inhibited,and when the initial stress is greater than the elastic limit of the rock,the promoting effect is shown.When loading different initial stresses(the rock peak stress is 90.58 MPa),the number of failure units and the crack propagation length of the combined hole are accord with the trend of“decreasing first and then increasing”,and the stress value at the inflection point is 25 MPa,27.6%peak stress of the rock,which is consistent with the elastic limit stress value in the whole stress-strain curve of the rock.By extracting and analyzing the effective stress and vibration velocity at the measuring point,it can be seen that the coupling stress at the measuring point increases linearly with the increase of the initial stress(20~50 MPa),indicating that the initial stress plays a dominant role under the coupling action of the initial stress and the explosion stress.In the combined hole scheme,the advance cracking blasting creates a new free surface for the front row holes,and the vibration velocity monitoring at the monitoring point shows that the combined hole blasting plan has a good shock absorption effect.

关 键 词：初始应力 组合孔 联合破岩 数值模拟 

分 类 号：TD235.3[矿业工程—矿井建设]