孔内双点起爆条件下的爆炸能量传输与破岩效果分析  

Explosion energy transmission and rock-breaking effect of in-hole dual initiation

作　　者：冷振东 范勇 卢文波[3] 高启栋 周俊汝[3] LENG Zhendong;FAN Yong;LU Wenbo;GAO Qidong;ZHOU Junru(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang,Hubei 443002,China;Chongqing Engineering Technology Research Center of Industrial Explosive Materials,China Gezhouba Group Explosive Co.,Ltd.,Chongqing 401121,China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhanf Hubei 430072,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]中国葛洲坝集团易普力股份有限公司重庆市民用爆破器材工程技术研究中心,重庆401121 [3]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《岩石力学与工程学报》2019年第12期2451-2462,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51809016,51609127);重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0645)~~

摘　　要：爆破破岩过程中,起爆方式对爆炸能量传输和破岩效果有着重要影响。从理论上证明两相向传播的爆轰波的碰撞聚能效应,分析孔内双点起爆条件下的爆炸能量传输特征。采用张拉–压剪统计损伤模型计算不同起爆方式下的岩石爆破破碎范围,并结合台阶爆破现场试验对比不同起爆方式下的爆破块度分布规律。结果表明,孔内双点起爆时两束相向传播的爆轰波在炮孔中部发生正碰撞,碰撞点附近的压力大于两冲击波的强度之和,局部破岩能力显著增强。双点起爆条件下炮孔附近岩体的张拉破坏区和压剪破坏区体积均大于常规的孔底、孔口、中间起爆,当改变孔内双点起爆的起爆点位置时,压剪破坏区域体积变化不大,而张拉破坏区域体积有明显的改变。可以通过合理设计起爆点的位置和数量,利用爆轰波、冲击波的碰撞来调整炸药爆炸能量的空间分布,从而显著提高局部爆破破岩能力,以满足不同的工程要求。In the process of rock fragmentation by blasting,the initiation mode has an important influence on the energy transmission and rock-breaking effect. The accumulated energy effect by collision of two oppositely traveling in-hole detonation waves was proved theoretically,and the energy transmission characteristics under the condition of dual initiation were analysed. The rock-breaking scopes under different initiation modes were calculated adopting a tension and compression-shear statistical damage model,and the fragmentation size distributions under different initiation modes were also investigated by comparing the field test results of bench blasting. The results show that when the two in-hole detonation waves collide in the middle of the borehole,the pressure near the collision point is greater than the sum of the strength of the two detonation waves and the local rock fragmentation degree is significantly improved.Under the condition of dual initiation,the volumes of tension and compression-shear failure zones of rock mass near the borehole are larger than those of bottom,top or middle initiation. When the initiation point position of in-hole dual initiation is changed,the volume of the compression-shear failure zone changes little but the volume of the tension failure zone changes obviously. Therefore,through reasonably designing the location and quantity of the initiation points,the spatial distribution of explosion energy can be adjusted by the collision of detonation wave and shock wave to improve the fragmentation degree of local rock and to meet different engineering requirements.

关 键 词：爆炸力学 岩石破碎 双点起爆 爆轰波和冲击波碰撞 能量传输 

分 类 号：O384[理学—流体力学]