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为研究含平行双裂隙砂岩的力学特性及裂纹演化特征,利用经过校核的细观参数通过离散元软件PFC2D建立数值模型,并对模型进行单轴压缩模拟。研究结果表明:含平行双裂隙砂岩的峰值强度、峰值应变及弹性模量与完整试样相比均有不同程度的劣化;随着平行双裂隙倾角的增大,试样的峰值强度、峰值应变及弹性模量呈增大趋势;当裂隙倾角为0时,裂纹首先在裂隙中部萌生,并向试样端部发展,当裂隙倾角为30°、45°及60°时,裂纹首先在裂隙尖端部分的应力集中区处萌生,并不断发展贯通,最终扩展到试样端部,当裂隙倾角为90°时,裂纹首先于试样端部萌生,并不断朝轴向发展。
In order to study the mechanical characteristics and crack evolution characteristics of sandstone with parallel double cracks, the numerical model of PFC2D using discrete element software was established by using the verified mesoscopic parameters and uniaxial compression simulation of the model. The results show that the peak strength, the peak strain and the elastic modulus of double fractured sandstone with parallel fractures all have different degrees of degradation compared with the intact samples. With the increase of dip angle of parallel double fractures, the peak intensity, peak strain And the elastic modulus increases. When the crack dip is 0, the crack first sprouts in the middle part of the crack and develops toward the end of the sample. When the crack dip angle is 30 °, 45 ° and 60 °, Part of the stress concentration area at the initiation, and continue to develop through, and eventually extended to the end of the specimen, when the crack angle of 90 °, the crack initiation first in the specimen, and continue to develop toward the axial direction.