SPATIAL-TEMPORAL CHARACTERISTICS OF ACOUSTIC EMISSION OF ROCK SAMPLE WITH REGULAR FAULT AND A COLUMNAR BARRIER DURING DEFORMATION
含障碍体平直断层标本变形过程中群体微破裂事件的时空演化特征

A physical model of regular fault containing a columnar barrier is designed, which can conceptually be used to simulate the barrier or strong area concerning the earthquake pregnancy. Biaxial compression experiment on middle-size rock sample with a regular fault and a columnar barrier is carried out, and the spatial-temporal characteristics of acoustic emission(AE) is studied. Results show that (1) Due to the complex actions between the hanging wall and lower wall, as well as the barrier, an alternate AE activity in different areas becomes the most remarkable feature during deformation process of the sample. (2) The pre-condition for instability of regular fault containing a barrier is that the barrier should be failed firstly with the increase of the loading. Very different AE spatial-temporal features are shown before and after the barrier failure. (3) The total deformation amount of this sample is larger and its cumulated AE frequency increases exponentially. During the later weaken period, there are only a few AE events in barrier and surrounding area. Abrupt instability happens under such a relative quiet background. (4) The values of b of G-R relationship for different pre-setting tectonic patterns have some obvious differences, the regional differences of b value related to different tectonics are remarkable.