单轴压缩下含表观裂纹盐岩力学特性试验研究

利用RMT-150B岩石力学多功能系统,对不同形态的含表观裂纹盐岩的力学特性进行试验研究,分析了表观裂纹对盐岩的强度和变形性能影响以及盐岩表观裂纹扩展及其贯通模式。表观裂纹扩展演化主要分两类:一类是试件初始表观裂纹扩展形成主裂纹;二类是试件初始表观裂纹闭合,而重新萌生微裂纹,聚集、扩展形成主裂纹,同时,附近伴随生长次生裂纹。表观裂纹盐岩的贯通模式主要表现为拉贯通和拉剪贯通,未呈现明显的压贯通等其他贯通模式;受自身结构致密性影响,裂纹贯通路径呈现明显的曲折线。竖向贯通裂纹对盐岩变形模量影响较大,而倾斜裂纹对盐岩变形模量影响相对较小。

MECHANICAL BEHAVIOR OF SALT ROCK WITH DISCONTINUOUS FISSURES WITH UNIAXIAL COMPRESSION TEST

This paper examines the mechanical behavior of salt rock containing fissure. The uniaxial compressive tests are carried out with a servo-controlled test machine RMT-150B.The effect of discontinuous fissures on strength and deformation of salt rock are analyzed. The discontinuous fissures coalescence the behavior of salt rock and its transfixion mode. The discontinuous fissure extension evolution is mainly divided into two types. The main fissures extended from the initial discontinuous fissures of salt rock specimens are the first type. The second type is that the initial discontinuous fissures of specimens are closed and then new micro-fissures are initiated from other place. They are gathered together and formed the main fissures. At the same time, the secondary fissures grow tardily. The tensile transfixion mode and tension-shear transfixion mode are the main transfixion models for salt rock containing discontinuous fissures. Influenced by their own structure compactness, the paths of fissures coalescence presents obvious zigzag line. Effect of vertical transfixion fissures on deformation modulus of salt rock is larger than that of inclined crack.