脆性岩石的细观裂纹损伤及其时效特征

ON MESOCRACK DAMAGE OF BRITTLE ROCKS AND ITS TIME-DEPENDENT CHARACTERISTICS

本文在单调加载和恒载蠕变条件下进行了脆性岩石损伤动态全过程的细观试验。研究了细观裂纹的形式、发展及其损伤效应,探讨了断裂过程区的细观裂纹损伤特性。结果表明,细观裂纹是导致脆性岩石损伤极其重要而基本的因素。且具有显著的时效特征。在此基础上,将细观裂纹几何参数与岩石宏观力学参量相联系,分别建立了脆性岩石在单调加载和蠕变条件下的细观裂纹损伤模型,并作了相应验证。

Based on the mesodamage tests of some brittle rocks under monotonic loading and creep condition, this paper investigates on the formation and development of mesocracks and their damage effects, as well as the mesocrack damage characteristics in the fracture process zone of a main crack. It is shown that the mesocrack is not only fundamental to the damage of brittle rocks, but also evidently time-deependent. On the basis of the test results, the paper relates the geometrical parameters of mesocracks with the macromechanical variables together. Thus a mesocrack damage model is proposed and verified herein for brittle rocks under monotonic loading and creep condition.