地下层状岩体爆破的DDA方法模拟研究  

Simulation of Underground Layered Rock Blasting by the DDA Method

作　　者：杜鑫 甯尤军 杨军[3] Du Xin;Ning Youjun;Yang Jun(School of Mechatronic Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,P.R.China;Research Institute of Engineering Safety Assessment and Protection,Southwest Petroleum University,Chengdu,Sichuan 610500,P.R.China;State Key Laboratory of Explosion Science and Technology,Beijing institute of Technology,Beijing 100081,P.R.China)

机构地区：[1]西南石油大学机电工程学院,成都610500 [2]西南石油大学工程安全评估与防护研究院,成都610500 [3]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《地下空间与工程学报》2023年第3期955-961,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51774043)。

摘　　要：爆破破岩是爆炸应力波和爆生气体压力共同作用的结果,岩体不连续面和地应力是影响地下岩石爆破的重要因素。在非连续变形分析(DDA)方法中引入接触阻尼算法,同时改进爆腔搜索算法,采用递归策略搜索联通裂隙网络,实现节理岩体爆破模拟中爆腔的实时跟踪,进而对爆炸应力波和爆生气体共同作用下地下层状岩体的单孔爆破进行数值模拟,研究节理间距对破岩效果的影响。结果表明:节理对爆炸应力波的衰减作用随着节理间距的增大而明显减弱,相应的爆腔体积增大和爆腔压力衰减减慢;节理间距的增加将减慢爆破能量的衰减,从而导致更多的裂纹数量和更大的破岩程度;当节理间距较小时,爆生气体破岩作用较大,而随着节理间距的增加,爆炸应力波破岩作用愈加明显;节理的存在还将导致爆破径向裂纹沿节理面的偏转并进而继续沿径向扩展或停止扩展;节理间距越大,径向主裂纹发育也越明显。Rock fragmentation by blasting is the result of the combined action of explosion stress wave and explosion gas pressure.Underground rock blasting is affected by two important factors including the discontinuous surface and in-situ stress,among others.In the discontinuous deformation analysis(DDA)method,the contact damping algorithm is introduced and the search algorithm of blasting chamber is improved.Connected fracture network is searched by a recursive strategy to actualize the real-time tracking of blasting chamber in the blasting simulation of jointed rock.Thereafter,the single-hole blasting of underground layered rock is simulated to study the influence of joint spacing on rock fragmentation under the combined action of explosion stress wave and gas pressure.Results indicate that the attenuation of explosion stress wave in the rock decreases obviously with the increase of joint spacing,and correspondingly the volume of blasting chamber increases and the explosion gas pressure attenuates more slowly.The increase of joint spacing will slow down the attenuation of blasting energy,resulting in more cracks and greater rock fragmentation.With smaller joint spacing,the effect of explosion gas pressure on rock fragmentation is important,and with the increase of joint spacing,the effect of explosion stress wave on rock fragmentation becomes more significant.Moreover,it is found that the radial cracks may deflect along the joint surface and then continue to develop radially or stop.With the increase of joint spacing,more obvious radial main crack development is also observed.

关 键 词：岩石爆破 地下层状岩体 爆炸应力波 爆生气体 非连续变形分析 

分 类 号：TD235[矿业工程—矿井建设]