深部围压对岩体爆破损伤范围影响数值分析

深井矿山开采条件下,地应力环境更加复杂,为研究高应力围压对爆破破岩效果的影响,采用ANSYS/LS-DYNA分析软件建立了三维数值计算模型,设定开采深度H分别为1000 m、2000 m和3000 m三种方案,开展三向围压下岩体爆破损伤范围数值分析。研究表明:在相同岩石和爆破参数条件下,随着开采深度的增加,围岩压力随之增大,围压总体上对爆破损伤范围起到抑制作用,使得装药区的爆破损伤体积由H=1000 m时的2.21 m3降低至H=3000 m时的0.52 m3,降低幅度达到76.5%;且对拉伸破坏的抑制效果更明显,岩体爆破损伤类型由拉伸破坏逐渐向剪切破坏转化。高围压条件下,岩体的围岩约束作用增大,一定程度上加大了爆破难度,但超过一定范围易于诱发岩爆事故。

Numerical Analysis on Influence of Deep Confining Pressure on Blasting Damage Range of Rock Mass

Under the conditions of deep mine,the geostress environment is complicated.In order to study the effect of high confining pressure on blasting rock breaking,the ANSYS／LS-DYNA software was used to establish the three-dimensional numerical model.The mining depth H with 1000 m,2000 m and 3000 m was used to carry out nu-merical analysis of rock blasting damage range under three-dimensional confining pressure.The results show that un-der the same conditions of rock and blasting parameters,with the increase of mining depth,the pressure of surround-ing rock increases,and the confining pressure generally inhibits the scope of blasting damage.The blasting damage volume in the charging zone decreases from 2.21 m3 at H＝1000 m to 0.52 m3 at H＝3000 m,reduced 76.5%.The effect of inhibiting the tensile damage is more obvious.The types of rock blasting damage gradually transform from tensile failure to shear failure.Under the conditions of high confining pressure,the confining action of surrounding rock increases the blasting difficulty to a certain extent,but easily induce the rock burst accident beyond a certain range.