含倾斜夹层盐岩体变形与破损特征分析

为了研究含倾斜非盐夹层盐岩体的变形与破损特性，开展了含倾斜夹层盐岩试样的单轴、三轴压缩试验，并结合复合岩体破坏的理论分析，探讨了界面黏结应力的变化规律及其影响因素，揭示了倾斜层状盐岩体变形与破坏特征及其机制。研究表明，倾斜夹层对盐岩体的变形与破损具有显著影响。夹层各部破损形式与其所处位置有关；裂纹在界面处最先萌生、进而扩展到夹层和盐岩层；试验观察到盐斑的穿晶断裂现象并揭示了其力学机制；夹层厚度影响着盐岩体整体性能和破损特性，相对于薄夹层、中厚夹层更容易形成宏观裂纹；围压作用减少了夹层不同部位的破裂形态差异及界面黏结应力差异。该结果为含地层倾角盐岩矿区储气库的造腔优化及其稳定性、密闭性分析提供了理论参考，建议造腔前应优选地质层段，以同时满足稳定性和密闭性要求。

Analysis of deformation and fracture characteristics of salt rock with tilted interlayer

In order to reveal the deformation and failure characteristics of salt rock with tilted unsalted interlayer, uniaxial and triaxial compression experiments are carried out. With failure mechanism analysis of stratified rock mass, the variation and impact factors of bonding stresses are investigated; and the failure characteristics and mechanisms of tilted layered salt rock are revealed. The research indicates that tilted interlayer obviously affects the deformation and failure characteristics of rock samples. The failure patterns are related to the position of interlayer. Cracks initiate near interface firstly and then expand to interlayer and salt rock. Trans-granular fracture is observed and its mechanism is revealed. The overall performance of salt rock and characteristics of cracks are influenced by the thickness of interlayer; comparing with thin interlayer salt rock, macro crack tends to appear in the middle thick interlayer more easily. Confining pressure reduces the morphological difference of cracks in different positions of interlayer and the difference of bonding stresses on interface. The analytical result provides an important reference for the study of the cavern construction optimization and stability and tightness research of the salt caverns in the salt rock mineral area with stratum inclination. What’s more, optimizing the geological section to meet the demand of stability and tightness simultaneously is recommended before cavern construction.