高温周期变化与高围压作用下大理岩力学特性试验研究

为了探讨温度周期变化与高围压对大理岩变形、强度特性及破坏断裂损伤劣化的影响，采用MTS815.03电液伺服刚性岩石试验系统，选取四川凉山雅砻江大河湾锦屏二级水电站引水隧洞围岩大理岩试样分别进行不同温度变化（100～ 600 ℃），周期次数为8次。进行高围压（60 MPa）作用下全应力应变过程三轴压缩与单轴压缩对比试验，系统分析比较了温度循环与高围压作用对大理岩应力-应变关系曲线、峰值应力、残余应力，峰值应变、残余应变以及弹性模量等的影响。试验结果表明，大理岩随着温度升高，峰值强度、残余强度、弹性模量下降，峰值应变和残余应变随之增大；在同一温度下，随着循环次数增加，其弹性模量、峰值强度、残余强度降低，温度越高，降低越明显；多次循环后，岩石的脆性变大，应力-应变曲线峰后段不再平滑，残余应变变小，其研究成果为锦屏二级水电站引水隧洞围岩稳定性分析提供理论依据。

Study of mechanical performance of marble under high pressure and cyclic temperature

In order to research the influences of cyclic variation of temperature on the deformation, strength, damage and fracture, the contrast test of the uniaxial compression and triaxial compression, which is about the whole stress-strain behaviors of the marble under the action of cyclic (repeated 8 times) temperature from 100 ℃ to 800 ℃ and high confining pressure(60 MPa), is done by using hydraulic pressure servo rigidity rock mechanics experiment system MTS815.03. The specimens of the marbles come from the diversion tunnel of Liangshan Yalongjiang Dahewan Jinping Hydropower Station in Sichuan Province. We analyse the Influence of the high temperature and high cyclic temperature on the stress-strain behaviors, peak stress, peak strain, stress, residual strain and elastic ratio; it is shown that the peak strength, residual strength and elastic modulus decrease when the samples suffer more high temperature; at the same time, the peak strain and residual strain increases; at the same temperature, when the times of the cycle increasing, the elastic modulus, peak strength and residual strength of marble will decrease; and the higher temperature, the more obviously the decrease; after multiple cycle, the plastic characteristics of marble increase, the stress-strain curve behind the peak is not smooth, and residual strain diminish. The achievements mentioned above provide the basis for the diversion tunnel of Jinping Hydropower Station.