Discrete Element Modeling of Crack Initiation Stress of Marble Based on Griffith's Strength Theory
Discrete Element Modeling of Crack Initiation Stress of Marble Based on Griffith's Strength Theory
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基于格里菲斯强度理论的大理石裂纹萌生应力离散元建模
DOI：
10.1155/2020/8876661
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发表时间：
2020
影响因子：
1.8
通讯作者：
Tu Fubin
中科院分区：
文献类型：
--
作者：
Wang Suifeng;Tan Fei;You Minglong;Jiao Yu-Yong;Tu Fubin
研究岩石的起裂应力对于了解岩石的渐进损伤过程和内部裂纹的演化规律具有重要意义。本文采用颗粒流方法对不同围压下含椭圆裂纹的大理岩模型进行了双轴压缩试验。根据压缩过程中岩石微裂纹的演化状况，定义了四个特征应力来反映大理石的渐进损伤过程。采用两种不同的方法求取岩石的起裂应力，并将计算结果与Griffith强度理论的计算结果进行了比较，以验证该理论在压应力下的准确性。基于数值模拟结果，描述了大理岩强度参数随损伤程度的演化规律。根据峰值应力与起裂应力之间的比例关系，提出了一种新的起裂应力预测方法，并验证了该方法的有效性。研究结果对解决地下空间工程中遇到的底板开裂和岩爆等重大问题具有一定的指导意义。
Investigating the crack initiation stress of rocks is vital for understanding the gradual damage process of rocks and the evolution law of internal cracks. In this paper, the particle flow code method is used to conduct biaxial compression tests on a marble model with an elliptical crack under different confining pressures. According to the evolution status of microcracks in the rock during compression, four characteristic stresses are defined to reflect the gradual damage process of the marble. Two different methods are used to obtain crack initiation stress of rocks, and the calculation results are compared with those based on Griffith’s strength theory to verify the accuracy of this theory under compressive stress. Based on the numerical simulation results, the evolution law for the strength parameters of marble with the degree of damage is described. According to the proportional relationship between the peak stress and crack initiation stress, a new method for predicting the initiation stress is proposed, whose effectiveness is verified. Overall, the results of this study can serve as a useful guide for solving the important problems of slab cracking and rockburst encountered in underground space engineering.