不同应力条件下爆破开挖对围岩损伤效应的数值模拟研究
Numerical Simulation of Blasting Excavation Induced Damage Under Different In-Situ Stress Conditions
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摘要: 根据芦岭矿的工程地质资料,拟定了硬岩和软岩的典型物理力学参数,并依托芦岭矿现场爆破参数,结合ANSYS/LS-DYNA软件,通过隐式-显式连续求解,完成了不同初始应力条件下硬岩和软岩巷爆破开挖的模拟. 计算结果表明,在5~25 MPa应力水平时,随着地应力的增加,近爆腔处围岩的损伤程度并不发生变化,而远离爆腔处围岩损伤程度明显减小,地应力对爆炸载荷所造成损伤抑制作用明显;相同爆破参数下,软岩爆破较硬岩更易受地应力的作用.Abstract: No matter with what kinds of control blasting technologies, the blasting excavation will cause damage to the remaining rock. Representative physico-mechanical properties were studied out according to the engineering geological data of Luling mine. Relying on site blasting parameters, combined with ANSYS/LS-DYNA software, the hard rock and soft rock in different in-situ stress conditions of the blasting excavation were simulated. The numerical results show that, in the 5 to 25 MPa in-situ stress level, the damage degree of surrounding rock near blasting cavity does not increase with the increase of in-situ stress, but the degree of the rock damage caused by explosion shock load is significantly reduced away from explosion cavity. Therefore in-situ stress is easy to restrain blasting damage. In same blasting parameters, compared to the hard rock, blasting in soft rock is more susceptible to the influence of in-situ stress.
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