基于数字图像处理的含不同开度裂隙组合花岗岩破裂规律研究

为了研究不同开度裂隙组合花岗岩破裂规律,通过RFPA-DIP数值模拟软件,基于花岗岩真实细观结构建立含不同开度裂隙组合模型,进行单轴压缩数值试验。分析了模型的应力-应变曲线特征,峰值强度特征,裂纹扩展规律和声发射特征。结果表明：应力-应变曲线上升与跌落次数随裂隙开度的增加而增多；1 mm裂隙随着加载的进行而闭合,对模型力学特性影响较小；当两裂隙开度大于或等于2 mm时,出现岩桥区成核现象；开度较大的裂隙其裂纹扩展优先于开度较小裂隙；随着开度增加,峰值抗压强度、裂纹贯穿时声发射次数和总次数呈减小趋势。研究结果对含裂隙岩体地下工程建设具有一定的参考价值。

Study on fracture law of granite with different crack degree based on digital image processing

Seven fractured granite models with different aperture were established by RFPA2D-DIP numerical simulation software, and uniaxial compression tests were carried out on the models. Based on the test results, the variation characteristics of stress-strain curve, peak strength characteristics, crack propagation law at different stages of the model and acoustic emission characteristics in the process of model rupture are analyzed. The results show that:With the increase of crack opening, the stress-strain curve rises and falls several times. The aperture of 1 mm closes with the loading, which has little influence on the mechanical properties of the model. When the aperture of the two fractures is greater than or equal to 2 mm, nucleation occurs in the rock bridge area. The crack growth of the aperture with large opening is more important than that with small opening.With the increase of the opening, the peak compressive strength, the number of AE and the total number of AE during the crack penetration decrease.The research results have certain reference value for underground engineering construction of fractured rock mass.