地震非均匀度物理意义的实验研究

资料表明某些强地震前中小地震的地震非均匀度（GL值）参数在强地震孕育进入中期或短期阶段出现明显异常变化， 显示出区域中小地震活动状态发生变化. 本文通过对含有障碍体的平直断层、 挤压型雁列式断层及Ⅲ型剪切裂纹等3种类型的岩石样本变形破坏过程声发射事件时间序列的分析， 讨论了GL值变化的物理意义. 计算结果表明， 这3种标本变形破坏过程中, 在应力应变处于非弹性阶段前夕或在岩石整体破裂失稳前破裂成核期间， GL值出现持续大于１的异常变化. 表明GL值能较好地刻画受压岩石破坏前的应变的非弹性变化， 具有一定的标本破裂指示意义. 

STUDY ON THE PHYSICAL MEANING OF SEISMIC INHOMOGENEOUS DEGREE BY ROCK FRACTURE EXPERIMENTS

It is observed that the parameter of seismic inhomogeneous degree (GL value) calculated from the earthquake catalog shows obvious abnormal changes prior to the strong earthquakes, indicating the state change of local earthquake activity. This paper focuses on the physical meaning for the abnormal changes of the GL values based on the temporal sequences of acoustic emission events for three types of rock samples containing macro-asperity, compressional en-echelon fracture and model-Ill shearing fracture. The results indicate that for the three types of rock samples, there are continuous abnormal changes of GL value (>1) just before the non-elastic deformation occurs or during the process of nu-cleation prior to the instability. Therefore it can be concluded that GL value can well portray the non-elastic deformation before rock fractures and it can be used as an index of rock samples fracture.