高地应力岩石双孔爆破损伤演化研究

Research on damage evolution of rock caused by double-hole blasting under high in-situ stress

为探究地应力和侧压力系数对爆破损伤范围及损伤分布的影响,基于RHT本构建立双孔爆破模型,运用LS-DYNA软件对不同地应力水平下的岩石爆破进行了数值模拟,对裂隙的扩展、贯通过程进行了分析,研究了高地应力对爆破损伤演化的影响。研究表明:裂隙区比粉碎区对地应力的变化更敏感,地应力对裂隙区的发育特别是主裂隙的扩展起抑制作用;随着静水地应力的增加,粉碎区和裂隙区范围、主裂隙长度逐渐减小,岩石破碎和裂隙贯通愈发困难;非静水应力下,最大主应力对裂隙扩展具有导向作用,侧压力系数越大,岩石损伤各向异性越明显;根据高地应力岩石损伤特性提出了爆破优化措施。

To explore the influence of in-situ stress and lateral stress coefficients on blasting damage range and distribution,the double hole blasting model was established based on RHT constitutive model.The numerical simulation of rock double-hole blasting under different in-situ stress levels was carried out by LS-DYNA software.This paper analyzes the process of blasting crack propagation and penetration,and focuses on the influence of high in-situ stress on blasting damage evolution.The research shows that the fracture zone is more sensitive to the change of in-situ stress than the crushing zone,and the in-situ stress inhibits the development of the fracture zone,especially the expansion of the main fracture.With the increase of hydrostatic in-situ stress,the range of crushing zone and fracture zone and the length of main fracture gradually decrease,and it is more and more difficult for rock fragmentation and fracture penetration.Under the non-hydrostatic in-situ stress,the maximum principal stress has a guiding effect on crack propagation.The anisotropy of rock damage becomes more obvious with the increase of lateral stress coefficient.In addition,several blasting optimization measures are proposed according to the damage characteristics of high ground stress rock.