【摘要】 <正> 地震的孕育过程与地壳中的应力变化和岩石变形密切相关。为了探讨地形变异常和地应力变化异常作为地震前兆的物理本质,开展相应的岩石破裂实验研究是必要的。 早在Kármán和Griggs开展岩石力学实验的时候,就已观测到一个现象,即在岩石发生脆性破裂的场合,主破裂并不发生在岩石的应力状态达到其峰值强度(最大承载更多还原

【Abstract】 The rupture experiments have been carried out on the brittle rocks of gabbro and granite, with the deformation and stress drop emphatically measured before the occurrence of principal rupture. The results show that the precursory stress drop and off-linear deformation took place prior to the principal rupture of the brittle rocks, and the principal rupture occurred during the process of stress drop. The relations between the features of the precursory stress drop and deformation and the confining pressure are also studied. It is indicated that the precursory stress drop and deformation are increased as the confining pressure increases. The time orders for the appearances of precursors before ruptures of four kinds of rocks are compared in line with the experimental results of wave velocity and acoustic emission anomalies prior to the principal rupture of rocks.更多还原