高温遇水冷却岩石循环加卸载力学性能试验研究

为研究高温遇水冷却后不同岩性岩石在循环加卸载条件下的物理特性和力学响应特征的变化规律，对高温遇水冷却后的花岗岩、大理岩及绿砂岩试件分别开展了单轴压缩和循环加卸载试验. 结果表明，当加热温度超过400 °C后，三类岩石的体积增长率显著增加，400 °C可以作为三类岩石物理参数发生突变的阈值温度.总体上，三类热处理水冷却岩石的单轴抗压强度随温度的升高而降低，但花岗岩在200 °C温度处理后峰值强度比常温时有所增加. 在循环荷载作用下，花岗岩滞回曲线接近于线性，上限应力较高且不可逆变形小；而绿砂岩和大理岩的上限应力低于花岗岩且变形较大.相同温度热冲击下滞回环宽度大小顺序为绿砂岩>大理岩>花岗岩.随循环次数的增加，三类高温遇水冷却岩样的塑性变形减小，弹性模量增大，试件强度较单轴压缩均有提高；随温度升高，破坏面裂纹更为发育，破裂岩屑更为细碎. 

Experimental Study on Mechanical Properties of Water-Cooled High Temperature Rock Under Cyclic Loading

In order to analyze the physical and mechanical properties of water-cooled high temperature rock under cyclic loading, uniaxial compression and cyclic loading tests were carried out on granite, marble and sandstone specimens respectively. The results show that when the heating temperature exceeds 400 °C, the volume growth rate of the three types of rocks increases significantly, thus 400 °C can be taken as the threshold temperature for the sudden change of physical parameters of the three types of rocks. In general, the uniaxial compressive strength of three types of water-cooled high temperature rocks decreases with the increase of temperature, however the peak strength of the 200 °C granite is higher than that at room temperature. Under cyclic load, the hysteretic curve of granite is approximately linear with a larger high limit stress and lesser irreversible deformation; while for green sandstone and marble samples, the high limit stress is lower than that of the granite sample with a larger deformation. With the increase of the cyclic number, the plastic deformation of the three types of rock decrease, the elastic modulus increase, and the strength of the rocks increases then that under uniaxial compression; with temperature increases, the cracks on the failure surface are more developed, and the broken rock are more finely broken.