偏心不耦合系数对爆破裂隙影响的数值模拟

Numerical simulation of the effect of eccentric decoupling coefficient on blasting crack

为了探究偏心不耦合爆破岩石的最优不耦合系数,建立6组单孔二维ANSYS/LS-DYNA模型,分析PK本构岩石在偏心不耦合爆破荷载作用下的损伤效应。结果表明:①随着偏心不耦合系数的增加,不耦合侧破碎区半径呈现先显著减小再缓慢减小的趋势,而耦合侧为先快速增大再缓慢减小;不耦合侧裂隙延伸长度呈现先略减小而后缓慢增加最后显著降低的趋势,耦合侧则基本不变;不耦合侧爆心距20 cm处质点振动峰值速度呈显著增加趋势;②当不耦合系数不变时,岩石抗压强度越大裂隙延伸长度越长,反之越短。当不耦合系数k=1.7时,不同抗压强度岩石在偏心爆破荷载作用下实现不耦合侧破碎区半径最小而耦合侧较大,不耦合侧裂隙少且耦合侧较发育,有效减小非爆破区岩石爆破效应,为最优偏心不耦合系数。

In order to explore the optimal decoupling coefficient of eccentric decoupled blasting rockmass,six sets of single-hole two-dimensional ANSYS/LS-DYNA models are established to analyze the damage effects of PK constitutive rock under eccentric uncoupled blasting loads.The results show that:①With the increase of the eccentric decoupling coefficient,the radius of the crushing zone on the decoupled side decreases significantly first and then slowly,while the coupled side increases rapidly first and then slowly decreases.On the decoupled side,the fracture extension length decreases slightly at first,then increases slowly and then decreases significantly,while on the coupled side,the fracture extension length remains unchanged.The peak particle vibration velocity increases significantly at 20 cm distance from the decoupled side.②When the decoupling coefficient is unchanged,the larger the rock strength,the longer the fracture extension length,and the shorter the vice versa.When the decoupling coefficient k=1.7,the rock with different strength under eccentric blasting load can achieve the smallest fracture radius of the decoupled side and the larger coupling side,the few cracks on the decoupled side and the more developed coupling side,effectively reducing the blasting effect of the rock in the non-blasting area,which is the optimal eccentric decoupling coefficient.