Carrara大理岩高温高压变形实验研究

利用高精度的Paterson高温高压流变仪对Carrara大理岩在高温(873~1173K)高压(~300MPa)以及约10-6~10-3s-1应变速率下进行了三轴压缩变形实验。结果表明,在等应变速率条件下,其强度随着温度的升高而降低;在等温和等压条件下,其强度随着应变速率的增加先快速增加而后缓慢增加。在应变速率对差应力的双对数投图中,我们发现随着温度的升高拟合直线的斜率减小,并且在873K和高应变速率时973K温度下Carrara大理岩的流变本构方程服从指数律变化关系;而在高温(1073K和1173K)和973K低应变速率条件下Carrara大理岩的应力指数n为5.3~7.7,且服从幂次律变化关系。因此,Carrara大理岩在本研究的实验条件下主要有两种变形机制,一种是用指数律表示的高应力变形机制;另一种是用幂次律表示的中等应力变形机制。

Experimental study of deformation of Carrara marble at high pressure and high temperature.

Triaxial compression deformation experiments on Carrara marble were performed in a Paterson gas-medium apparatus at a confining pressure of 300MPa, temperatures of 873~1173K, and strain rates of ca.10^-6~10^-3s^-1. The experimental results show that at a constant strain rate, the strength of Carrara marble decreases as temperature increases. At a constant temperature, the strength increases rapidly and then slowly with strain rate increasing. In the log-log plot of strain rate vs. differential stress, we find the slopes of the fitted lines for constant-temperature experimental data decrease with increasing temperature and the data for experiments at 873K and for experiments of high strain rates at 973K, best fit the exponential relationship. The results at high temperatures (e.g., 1073K, and 1173K) and the results for lower strain rates at 973K, however, best fit the power law relationship with a stress exponent about 5.3~7.7. Therefore, we can draw that there are two main deformation mechanisms of Carrara marble in our laboratory experiments, one of which is represented by the exponential relationship for high stresses and the other is the power law mechanism for moderate stresses.