岩石爆破损伤范围及损伤分布特征模拟分析

Simulation analysis of blast-induced damage scope and its distribution characteristics of rocks

  • 摘要: 为了研究岩石爆破损伤范围及损伤分布规律,基于LS-DYNA软件,采用HJC(Holmquist-Johnson-Cook)材料模型,探究了石灰岩爆破损伤范围随径向不耦合系数K增大的变化关系,接着对比分析了石灰岩、凝灰岩和花岗斑岩的爆破损伤分布规律,并用Logistic函数模型对损伤演化过程进行表征。结果表明:HJC模型在岩石爆破损伤模拟中具有很好的适用性;随着不耦合系数的增大,损伤半径与炮孔半径之比呈先快后慢的减小趋势;不同岩石的爆破损伤均呈反“S”形曲线衰减,但损伤分布特征存在一定差异性,石灰岩和凝灰岩的压碎区范围较大,与裂隙区界线清晰,而花岗斑岩压碎区范围较小,与裂隙区界线不明显。研究结果可为实际工程中爆破损伤的评估与控制提供一定参考。

     

    Abstract: In order to study the scope and distribution law of rock damage induced by blasting, using the Holmquist-Johnson-Cook model based on the LS-DYNA software, this study focuses on the variation of the blast damage scope of the limestone with the increase of a radial uncoupling coefficient K, and then the distribution law of damage under the condition of coupling charge is comparatively analyzed for the limestone, tuff and granite porphyry, and the damage evolution is further characterized by the Logistic function model. The simulation results show that the HJC constitutive model is capable of characterizing the blast-induced damage during the numerical simulation. The ratio of damage radius to bore-hole radius decreases fast first and then slowly with the increase of the radial uncoupling coefficient. The damage curves of different rocks all show an inverted-S attenuation, but there are some differences in the damage distribution characteristics. The crushing zones of the limestone and tuff are larger and the corresponding boundary between the crushing zone and the cracking zone is obvious, while the crushing zone of the granite porphyry becomes smaller and the corresponding boundary is indistinct. The research results can provide some technical references for the assessment and control of blast-induced damage in practical engineering.

     

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