关键词: 温度周期变化, 循环加温, 大理岩, 力学特性

Abstract: 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.

Key words: cyclic variation of temperature, circular heating, marble, characteristic of mechanics