The study on hydromechanical coupling properties of rocks is of great importance for rock engineering. It is closely related to the stability analysis of structures in rocks under seepage condition. In this study, a series of conventional triaxial tests under drained condition and hydrostatic compression tests under drained or undrained condition on sandstones were conducted. Moreover, complex cyclic loading and unloading tests were also carried out. Based on the experimental results, the following conclusions were obtained. For conventional triaxial tests, the elastic modulus, peak strength, crack initiation stress, and expansion stress increase with increased confining pressure. Pore pressure weakened the effect of the confining pressure under drained condition, which led to a decline in rock mechanical properties. It appeared that cohesion was more sensitive to pore pressure than to the internal friction angle. For complex loading and unloading cyclic tests, in deviatoric stress loading and unloading cycles, elastic modulus increased obviously in first loading stage and increased slowly in next stages. In confining pressure loading and unloading cycles, the Biot coefficient decreased first and then increased, which indicates that damage has a great impact on the Biot coefficient.

中文翻译：

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不同加载路径下砂岩应力渗流耦合特性试验研究

岩石流体力学耦合特性的研究对岩石工程具有重要意义。它与渗流条件下岩石结构的稳定性分析密切相关。在这项研究中，对砂岩进行了一系列排水条件下的常规三轴试验和排水或不排水条件下的静水压试验。此外，还进行了复杂的循环加载和卸载测试。根据实验结果，得出以下结论。对于传统的三轴试验，弹性模量、峰值强度、裂纹起始应力和膨胀应力随着围压的增加而增加。孔隙压力减弱了排水条件下围压的影响，导致岩石力学性能下降。看起来黏聚力对孔隙压力比对内摩擦角更敏感。对于复杂的加载和卸载循环试验，在偏应力加载和卸载循环中，弹性模量在第一个加载阶段明显增加，在接下来的阶段缓慢增加。在围压加载和卸载循环中，Biot系数先减小后增大，说明损伤对Biot系数影响较大。