School of Urban Construction,Yangtze University,Jingzhou
In order to study the crack propagation evolution and failure law of fractured rock mass under load, the prefabricated two non-coplanar fissures sandstone samples were prepared as the research object. The uniaxial compression test combined with the DIC technology was used to explore the influence of the fissure angles and ligament angles on the crack generation, propagation and failure mode of the samples. The results show that: (1) The crack first initiates from the boundary of the specimen and extends to the center of the specimen. As the loading progresses, the crack initiates at the crack tip and extends to the upper and lower ends of the specimen. (2) The evolution process and failure mode of new cracks in specimens are closely related to the dip angle characteristics of the fissures. With the increase of the fissure angle and ligament angle, the number of crack propagation shows the characteristics of first decreasing, then increasing and then decreasing, first decreasing and then increasing, and the failure mode of the specimen changes from tensile failure to tensile-shear composite failure. However, when the fissure angle increases to 90°, the specimen shows tensile failure again.(3) The transfixion of the rock bridge depends on the length of its horizontal projection. When the ligament angle is 0°, 30°, the horizontal projection length of the rock bridge is long, the rock bridge has no transfixion, When the ligament angle is 60°, 90°, 120°,the horizontal projection length of the rock bridge gradually decreases, and the rock bridge occurs direct transfixion. The research results can provide certain guiding significance for engineering design and optimization.
郑远龙,肖桃李,折海成,等. 雁行双裂隙类砂岩加载条件下裂纹扩展演化规律研究[J]. 科学技术与工程, , ():复制