爆炸荷载下深地下硬岩的动力模型及其数值分析

Dynamic model for deep hard rock under blast loading and its numerical method

为了提高深地下硬岩爆炸近区岩体动力行为预测的可靠性和准确性,引入改进的C.C.Grigorian模型,详细推导了本构方程的积分。基于LS-DYNA9703D二次开发平台拟制用户子程序,计算了岩体耦合装药时高围压条件下球状药包中心起爆时爆炸近区的岩体动力响应。研究了不同围压时空腔壁上质点永久位移规律,揭示了围压、岩体抗压强度与空腔半径变化之间的关系,并与类似试验结果及弹性模型、弹塑性模型的计算结果进行了对比分析。结果表明,改进的C.C.Grigorian模型的计算结果与实验符合较好,适用于高围压水平下的爆炸近区计算;爆炸空腔膨胀受围压约束显著,相对空腔半径和围压与岩体强度之比近似成线性关系。

To improve the reliability and accuracy of predicting the dynamic deep hard rock＇s behavior caused by the blasting near the cavity, the modified C. C. Grigorian model was introduced and the integration of the constitutive equation deduced in detail. Based on the LS-DYNA9703D＇s secondary development plat- form,the user-subroutine was coded, and simulation was made of the dynamic behaviors of the coupled- charge rock caused by the spherical charge blasting when the rock mass is surrounded by high confining pressure. Conditioned on different high confining pressures, the permanent displacements of the particle on the cavity were analyzed. The relationship among confining pressure, rock mass＇s compressive strength and the radius of cavity was revealed. The simulated results and the related experimental results were com- pared. The results show that the modified C. C. Grigorian model agrees with the similar test and is suitable for the calculations on the cavity surrounded by high confining pressure, and the swelling of the blasting cavity is significantly restricted. The relative cavity＇s radius and the ratio of the rock mass＇s strength and the confining pressure is nearly linear.