不同加载路径对岩石变形特性的影响

DEFORMATION PROPERTIES OF SAMPLES UNDER DIFFERENT LOADING PATHS

以往在研究岩石的力学特性时,大都采用持续加载的方法进行试验,三向压缩试验也不例外。就绝大多数工程而言,所遇到的却是在某种应力状态下由于开挖而产生一个方向应力减小、其他几个方向应力增大的现象。根据工程对岩体稳定性评价的要求,应该模拟不同加载路径的应力状态下的试验条件,以便掌握在该试验条件下岩石所作出的力学响应。通过对红砂岩在不同加载路径条件下的三轴试验,分析了不同加载路径所得到的应力-应变曲线及其对岩石的变形影响,得出了在不同加载路径条件下,岩石变形表现与常规试验有较大差异,有着较明显的非线性特性的结论。

In underground excavation conditions, rock often undergoes very complicated loading and unloading process. However, in laboratory tests on rock, such as normal triaxial test, the loads are usually exerted gradually and continuously, which cannot simulate the real stress state of rock precisely. The test data of triaxial test of red sandstone under different loading paths are presented and the impact of different loading path on the deformation of rock samples is analyzed. Unlike the test results under normal triaxial procedures, the deformation of rock under different loading paths has nonlinear properties.