大理岩卸围压幂函数型Mohr强度特性研究

 对大理岩进行三轴试验和峰前、峰后卸围压试验。研究结果表明：直线型Mohr-Coulomb强度准则不能很好地反映大理岩峰前、峰后卸围压的强度特征；提出非线性Mohr强度准则——幂函数型Mohr强度准则；推导并做出了其在p平面上的屈服曲线，与Mohr-Coulomb强度准则在p平面上的屈服曲线进行比较。研究结果表明，幂函数型Mohr强度准则比直线型Mohr-Coulomb强度准则能更好地描述大理岩的强度特征。

POWER FUNCTION BASED MOHR STRENGTH CRITERION FOR MARBLE WITH UNLOADING CONFINING PRESSURES

Conventional triaxial test and pre- and post-peak unloading confining pressure tests of marble have been performed. Mohr stress circles under different confining pressures and envelopes are achieved. The results indicate that linear Mohr envelope can not match stress circle very well；and the Mohr-Coulomb criterion describing marble strength will bring large error. In order to solve the problem，a nonlinear Mohr strength criterion is proposed，i.e. power function Mohr strength criterion，to fit the test data and compare the theoretical values and test values. The failure curve of power function Mohr strength criterion in p plane is presented；and the failure curve of Mohr-Coulomb strength criterion is then compared. It is shown that the power function of Mohr strength criterion can describe marble strength much better.