单向围压下切槽爆破裂纹扩展规律研究  

Crack Propagation Law of Notch Blasting under Unidirectional Confining Pressure

作　　者：吴延梦 李洪伟[1] 苏洪[1] 梁昊 黄昕旭 刘涛[1] 储亚坤 WU Yanmeng;LI Hongwei;SU Hong;LIANG Hao;HUANG Xinxu;LIU Tao;CHU Yakun(School of Chemical Engineering,Anhui University of Science&Technology,Huainan 232000,Anhui,China)

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232000

出　　处：《高压物理学报》2023年第6期126-136,共11页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(52104074)。

摘　　要：深部煤矿爆破是初始地应力场与爆炸荷载共同作用的结果,采用单向动-静组合加载试验平台和动态焦散线试验系统,在有机玻璃板上施加与炮孔切槽平行或垂直的单向围压作用,探究了初始应力场强度对爆生裂纹的扩展规律。结果表明:炮孔切槽能够有效控制初始应力场的分布范围,促进能量集中释放,提高定向爆破效果,同时爆炸动载荷与围压静载荷分别在炮孔近区和远区占主导作用;水平初始应力场增强了切槽尖端应力集中程度,促进了主裂纹的扩展,且随着应力场增强,促进效果越明显,同时抑制了次裂纹的产生;竖直初始应力场降低了切槽尖端的应力集中程度,抑制了裂纹扩展,并使裂纹扩展模式由Ⅰ型转变为Ⅰ-Ⅱ复合型,且随着应力场的增强,剪切断裂越明显,且裂纹沿最大主应力方向扩展。The deep coal mine blasting is the combined action of the initial ground stress field and the explosion load.By using the unidirectional dynamic and static combined loading test platform and the dynamic caustic experimental system,the expansion law of the initial stress field intensity on the blasting crack is explored under the horizontal or vertical unidirectional confining pressure applied to the blasthole notch on the plexiglass plate.The test results show that the grooving of the blasthole can effectively control the distribution range of the initial stress field,promote the concentrated release of energy,and improve the directional blasting effect.At the same time,the dynamic effect of explosion and the static effect of confining pressure are dominant in the near and far areas of the blasthole,respectively.The horizontal initial stress field increases the stress concentration at the crack tip and promotes the growth of the main crack.With the increase of the stress field,the promotion effect is more obvious,and the occurrence of secondary cracks is inhibited.In contrast,the vertical initial stress field reduces the stress concentration at the notch tip,inhibits the crack propagation,and transforms the crack from typeⅠfracture to typeⅠ-Ⅱmixed fracture.With the increase of stress field,the shear fracture is more obvious,and the crack propagates along the direction of the maximum principal stress.

关 键 词：高地应力 切槽爆破 动态焦散线 裂纹扩展 高速相机 

分 类 号：O346.1[理学—固体力学]