地应力条件下水压爆破顶板裂纹扩展规律影响因素研究  

Study on the factors influencing the crack expansion pattern of hydrodynamic blasting roof under ground stress conditions

作　　者：谢二伟 杨永康[1] 孙得志 XIE Er-wei;YANG Yong-kang;SUN De-zhi(Key Laboratory of In-situ Modified Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,太原030024

出　　处：《工程爆破》2023年第5期96-104,共9页Engineering Blasting

摘　　要：为研究地应力条件下水压爆破顶板裂纹的扩展规律,利用LS-DYNA非线性动力有限元模拟软件,以铺龙湾煤矿10602沿空留巷切顶卸压为工程背景,分析了不同侧压力系数、不耦合系数及导向孔与爆破孔间距对水压爆破在外加导向孔条件下孔间裂纹扩展及孔间峰值有效应力的影响,并进行现场验证。结果表明:在侧压力系数0.5~4.0范围内,随着侧压力系数的增大,孔间岩石的环向压应力逐渐小于连孔垂直方向的压应力,使得裂纹的扩展方向逐渐由连孔垂直方向过渡到连孔方向;随着不耦合系数的增大,孔间裂纹呈现先增多后减少的趋势,其中不耦合系数为2.5时,孔间裂纹最多,孔间峰值有效应力相比于其他情况高出1.16~1.45倍;当不耦合系数为2.5,侧压力系数分别为0.5、1.0、2.0、4.0时对应的最佳炮孔间距为500、600、700、700 mm。不耦合系数选取2.5、侧压力系数为2,炮孔间距为700 mm时的现场试验,顶板裂纹贯穿,液压支柱支护阻力降低20%左右,切顶效果良好。In order to study the expansion law of cracking in the roof of hydraulic blasting under ground stress conditions,LS-DYNA nonlinear dynamic finite element simulation software was used to analyze the effects of different lateral pressure coefficients,uncoupling coefficients and spacing between pilot holes and blast holes on the expansion of inter-hole cracking and peak effective stress between holes in hydraulic blasting under the condition of additional pilot holes,using Pulongwan coal mine 10602 along the hollow stay lane to cut the roof and unload pressure as the engineering background,and to conduct field verification.The results show that in the range of lateral pressure coefficient 0.5-4.0,with the increase of lateral pressure coefficient,the annular compressive stress of inter-hole rock is gradually smaller than the compressive stress in the vertical direction of the connecting hole,which makes the crack expansion direction gradually transition from the vertical direction of the connecting hole to the direction of the connecting hole;with the increase of uncoupling coefficient,the inter-hole cracks show a trend of first increasing and then decreasing,in which the uncoupling coefficient is 2.5,the inter-hole cracks are the most The peak effective stress between holes is 1.16~1.45 times higher than the other cases;when the uncoupling coefficient is 2.5 and the lateral pressure coefficient is 0.5,1.0,2.0 and 4.0,the corresponding optimal hole spacing is 500 mm,600 mm,700 mm and 700 mm respectively;the uncoupling coefficient is 2.5,the lateral pressure coefficient is 2 and the hole spacing is 700 mm.Field test,the roof crack penetration,hydraulic pillar support resistance reduced by about 20%,good effect of roof cutting.

关 键 词：水压爆破 裂纹扩展 有效应力 侧压力系数 不耦合系数 孔间距 

分 类 号：TU746.5[建筑科学—建筑技术科学]