双孔切缝爆破裂纹扩展机理及损伤特性研究  

Study on Crack Propagation Mechanism and Damage Characteristics of Double-hole Cutting Blasting

作　　者：张宪堂[1] 陈长青 刘小康 夏姣姣 周红敏[1] ZHANG Xian-tang;CHEN Chang-qing;LIU Xiao-kang;XIA Jiao-jiao;ZHOU Hong-min(Shandong Key Laboratory of Disaster Prevention and Mitigation of Civil Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学山东省土木工程防灾减灾重点实验室,青岛266590

出　　处：《爆破》2024年第4期45-53,共9页Blasting

基　　金：国家自然科学基金项目(No.51874189);山东省自然科学基金资助项目(No.ZR2023ME106);2021年度矿山地下工程教育部工程研究中心开放基金资助项目(JYBGCZX2021102)。

摘　　要：为研究双孔切缝爆破控制断裂损伤效果,开展现场双孔切缝爆破试验,结合ANSYS/LS-DYNA软件构建试验双孔切缝爆破模型,对比分析其裂纹扩展与孔壁气体单元压力变化。现场结果表明:爆后两炮孔间在切缝方向形成贯穿相交断裂面,半眼残痕更加明显;改变切缝角度至157°,裂纹仍会向切缝方向发展,切缝导向作用不受角度改变而影响;增设孔间空孔时断裂效果优于无空孔切缝爆破,说明空孔的存在能有效改善切缝爆破的定向断裂效果。模型结果显示:裂纹扩展与损伤与现场结果基本拟合,对比分析双孔切缝爆破与普通光面爆破模型,应力波的叠加作用使得孔间裂纹发育发生偏转,在两炮孔间形成裂纹空白带;分析孔壁0°~90°周围气体单元压力峰值,切缝方向达到压力峰值的时间早于非切缝方向,切缝爆破在0°~15°区间内,压力峰值下降幅度较大,随后曲线逐渐趋于平缓,角度越大,峰值变化也越来越小;切缝管在爆炸过程中有效地控制爆炸能量的分布,在切缝处形成应力集中,最大应力峰值约为垂直方向4倍以上。On-site double-hole slitting blasting experiments were conducted to study the effect of controlling fracture damage by double-hole slitting blasting.A test double hole slitting blasting model was constructed using ANSYS/LS-DYNA software,and its crack propagation and changes in gas unit pressure on the hole wall were compared and analyzed.The on-site results indicate that an intersecting fracture surface is formed between the two blast holes in the direction of the cutting seam after the explosion,and the half-hole residue is more obvious.Besides,the cracks will still develop towards the cutting direction by changing the cutting angle to 157°,and the guiding effect of the cutting seam is not affected by the change in angle.Meanwhile,the fracturing effect of adding empty holes between blast holes is better than that of non-empty hole slot blasting,which indicates that the existence of empty holes can effectively improve the directional fracture effect of slot blasting.The model results of the crack propagation and damage are consistent with the on-site results.By comparing and analyzing the double hole slit blasting and ordinary smooth blasting models,the superposition effect of stress waves causes the development of cracks between the holes to deflect,which forms a crack void between the two holes.Though analyzing the peak pressure of gas units around the hole wall at 0°~90°,it is found that the time when the pressure peak reaches the slit direction is earlier than that in the non-slit direction.More importantly,the pressure peak decreased significantly,and then the curve gradually tended to flatten during the slit blasting range of 0°~15°.The larger the angle,the smaller the peak change.The slit tube effectively controls the distribution of explosion energy during the explosion process,which forms stress concentration at the slit,with the maximum stress peak being about four times higher than that in the vertical direction.

关 键 词：聚能切缝爆破 双孔爆破 数值模拟 爆破损伤 压力分析 

分 类 号：TD235[矿业工程—矿井建设]