初始地应力下不耦合装药对预裂爆破影响的数值研究

Numerical study on the influence of uncoupled charge on pre-splitting blasting under initial ground stress

为了研究初始地应力下不耦合装药对预裂爆破的影响,以国内某水电站左右岸坝肩槽边坡开挖为工程背景,通过对多孔不耦合装药爆破数值模型进行模拟,分析不同初始地应力下不耦合系数对岩体爆破的振动效应、岩体破坏形式、损伤范围和预裂缝形成效果。结果表明:垂直主应力不变时随着水平主应力增加,水平方向峰值质点振速(PPV)受到抑制,竖直方向PPV受到促进作用,不耦合系数K对各方向PPV起抑制作用。初始地应力的大小对岩体压碎区的形成无明显影响,对裂纹扩展长度起抑制作用。不耦合系数K增加使得岩体压碎区半径和裂纹扩展平均长度减小。相关研究成果可为类似工程提供借鉴。

In order to study the effect of uncoupling charge on presplitting blasting under initial ground stress,taking the excavation of the left and right bank dam abutment slope of a hydropower station in China as the engineering background,the numerical model of porous uncoupling charge blasting is simulated,and the vibration effect,rock mass failure form,damage range and presplitting effect of uncoupling coefficient on rock blasting under different initial ground stress are analyzed.The results show that when the vertical principal stress is constant,with the increase of the horizontal principal stress,the peak particle vibration velocity(PPV)in the horizontal direction is inhibited,and the vertical PPV is promoted,and the uncoupling coefficient K inhibits the PPV in all directions.The size of initial ground stress has no obvious effect on the formation of rock mass crushing zone,and has a restraining effect on the crack propagation length.The increase of uncoupling coefficient K reduces the radius of rock mass crushing zone and the average length of crack propagation.Relevant research results can provide reference for similar projects.