为了研究先爆孔损伤与地应力对不同埋深条件下岩石光面爆破损伤演化规律的影响,首先采用二维数值模拟确定了RHT模型适用于光面爆破的损伤阈值为0.5,然后建立三维模型,采用ANSYS-DYNA隐式-显式序列求解法对模型施加地应力,通过等效刚度折减模拟先爆孔损伤,探究了岩石损伤在空间中的分布规律。结果表明:地应力的存在对深部岩石的爆破损伤有抑制作用,且这种抑制作用会随埋深的增加而愈发明显;先爆孔爆破对岩石造成的损伤对后续光爆孔破岩有促进作用;不同埋深下进行光爆作业时最佳光爆层厚度及光爆孔间距均不一样,当同时考虑先爆孔损伤与地应力影响时,埋深较小时二者取值可适当增加,埋深较大时二者取值应随埋深的增加而相应减小。
To investigate the effect of pre-blast hole damage and in-situ stress on the evolution of damage in the smooth blasting of rocks at different burial depths, the damage threshold of 0.5 was first determined for the RHT model applicable to smooth blasting using 2D numerical simulations. A 3D model was then established and the ANSYS-DYNA implicit-explicit sequence solution method was used to apply in-situ stress to the model, and the equivalent stiffness was discounted to account for the damage of the pre-blast hole to investigate the distribution of rock damage in space. The results show that the presence of in-situ stress has an inhibitory effect on the deep rock blasting damage, and this inhibitory effect will increase with the depth of burial. The pre-blast hole damage to the rock catalyses the next smooth blasting to break the rock. When smooth blasting is carried out at different burial depths, the choice of the best smooth blasting layer thickness and the smooth blasting hole spacing is not the same. When considering both the pre-blast hole damage and the impact of in-situ stress, if the depth of burial is small, the two values should be appropriate to increase, if the depth of burial is larger, the two values should be appropriate to reduce with the increase in depth.
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