含缺陷岩样三轴压缩变形破坏过程颗粒流模拟  

Particle flow simulation of deformation and failure process of defective rock samples under triaxial compression

作　　者：王浩然 王志亮[1] 王星辰 WANG Haoran;WANG Zhiliang;WANG Xingchen(School of Civil and Hydraulic Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《水利水运工程学报》2021年第4期46-53,共8页Hydro-Science and Engineering

基　　金：国家自然科学基金雅砻江联合基金资助项目(U1965101);国家自然科学基金资助项目(51579062)。

摘　　要：为了研究岩桥倾角α对岩石力学行为和裂纹扩展机制的影响,采用PFC3D程序中的颗粒平行黏结模型,通过“试错法”获得一组能够反映完整花岗岩宏观力学特性的细观参数,并建立不同α下微孔洞与平行裂隙①、②组合的数值模型,对三轴压缩中岩样变形破坏过程进行了模拟分析。结果表明:α对起裂强度与峰值强度的比值未见显著的影响;当α=0°和75°时,裂纹扩展模式相似,裂隙①、②内外尖端均产生翼型裂纹,随后与微孔洞贯通;当α=15°、30°和90°时,裂纹的扩展模式比较接近,裂隙①、②内外尖端也可见翼型裂纹;当α=45°、60°时,裂纹呈类似方式扩展,裂隙①、②与微孔洞之间在剪切面上出现裂纹贯通,且在裂隙①、②外尖端有剪切裂纹,此时平行裂隙和微孔洞在剪切面上;剪切裂纹远多于拉伸裂纹,且微裂纹是从初始损伤部位开始扩展的。To study the influence of dip angle of rock bridge on rock mechanical behavior and crack propagation mechanism,the particle parallel bonding model in the PFC3D code was used to obtain a group of microscopic parameters,which could reflect the macroscopic mechanical properties of intact granite via the trial and error method.A numerical model of the combination of micro-void and parallel fissures①and②under different rock bridge angles was established,and the deformation and failure process of the sample in the triaxial compression were analyzed.Results show there was no significant effect on the ratio of the initiation strength to the peak strength;whenα=0°and 75°,the crack propagation modes were similar,and wing cracks were initiated at the inner and outer tips of the fissure①and②,and then coalesced with the micro-void;whenα=15°,30°,and 90°,the crack propagation mode was relatively close,the wing cracks could be observed at the tips of the fissures①and②;whenα=45°,60°,the cracks grew in a similar manner,there were crack coalescence on the shear plane between the fissures①and②and the micro-void,and there were shear cracks at the outer tips of the fissures①and②.In this case,both the parallel fissures and the micro-void were on the shear plane;the number of shear cracks was far more numerous than that of the tensile cracks,and the micro-cracks extended from the initial damage zone.

关 键 词：岩石 初始缺陷 岩桥倾角 裂纹演化 数值模拟 

分 类 号：TU45[建筑科学—岩土工程]