脉冲水射流破岩过程中的应力波效应分析  

Analysis on stress wave effect during the process of rock breaking by pulsed jet

作　　者：卢义玉[1,2] 张赛[3] 刘勇[1,2] 陆朝晖[1,2] 蒋林艳[1,2] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室,重庆400044 [3]重庆松藻煤电有限责任公司,重庆401445

出　　处：《重庆大学学报（自然科学版）》2012年第1期117-124,共8页Journal of Chongqing University

基　　金：国家自然科学基金委专项创新研究群体基金项目(50621403);重庆市杰出青年基金(CSTC2009BA6047);新世纪优秀人才支持计划(NCET-06-07677);国家重大科技专项大型油气田及煤层开发(2011ZX05065)

摘　　要：引入Johnson-Holmquist-Concrete岩石非线性本构关系,利用光滑流体粒子动力学方法,模拟了脉冲射流在破岩过程中应力波形成、传播及衰减过程,得出了高速脉冲射流作用下岩石表面不同位置处应力值随时间变化曲线,以及应力波峰值强度与离射流作用点距离的关系曲线,根据计算结果分析了岩石在应力波效应下的破坏行为以及射流速度、岩石性质对应力波效应的影响。分析结果表明:脉冲射流的应力波效应具有较强的局部性,应力波峰值强度随与射流作用点距离的增大而急剧减小;脉冲射流应力波强度、作用范围与射流速度呈正比例关系,其对岩石的体积破坏存在一个门限速度;不同岩性岩石在脉冲射流应力波作用下的破坏形式有所不同,砂岩等强度较低岩石的破坏形式主要为应力波对岩石加卸载过程中的拉应力下的裂纹扩展,而石灰岩、花岗岩等脆性硬岩的破坏形式主要为应力集中导致的纵向破坏。A mathematical model of rock breaking under pulsed jet is established by introducing the Johnson-Holmquist-Concrete constitutive relation and the smoothed particle hydrodynamics method. Based on this model, the formation, propagation and attenuation of stress wave during rock breaking by pulsed jet are simulated. The relations between pressure and time at different points on rock surface and the curve of peak stress wave versus distance to action spot are obtained. Destruction behaviors of rock under pulsed jet and effects on stress wave effect from jet velocity and lithology are studied according to the above calculation results, analysis results show that stress wave effect of pulsed jet acts locally and the peak stress wave shrinks sharply as the acting distance increases. The rock breaking mechanism of stress wave is tensile failure during the high speed process of load-unload. Power and effect range of stress wave is in high direct proportion with jet velocity. There is a threshold velocity before the macroscopic failure. Rocks of different lithologies have different destruction types under pulsed stress wave of pulsed jet. Destruction type of low strength rock like sandstone is crack propagation under the tensile stress during the high speed process of load unload, while the destruction type of high strength brittle rocks like granite and limestone is vertical failure of stress concentration.

关 键 词：脉冲射流 应力波 光滑粒子动力学 岩石破碎 

分 类 号：TD823[矿业工程—煤矿开采]