【摘要】 设计了含圆柱形障碍体的平直断层物理模型 ,在概念上可模拟断层面上与地震孕育相关的障碍体等强固区域 .开展了中等尺度岩石标本的双轴压缩实验 ,研究标本在变形过程中群体微破裂事件的时空演化 .结果表明 :( 1)由于标本预置断层两盘与障碍体之间、以及断层两盘彼此之间复杂的相互作用 ,使得交替活动成为含障碍体平直断层标本变形过程中最为显著的特征 ;( 2 )含障碍体平直断层标本能够发生动力学失稳的前提条件是障碍体在外加载荷作用下首先发生破坏 ,微破裂群体在障碍体破坏前后显示不同的时空演化特征 ;( 3)含障碍体平直断层标本失稳前的总变形量较大 ,弹性变形阶段微破裂累积频次呈指数增长 .而在其后的位移弱化阶段 ,在障碍体及围绕障碍体的围岩区域内微破裂事件稀少 ,突发失稳发生在相对平静的背景之上 ;( 4)不同构造组合变形过程中的微破裂群体具有明显不同的b值 ,b值与构造相关的区域性差异是明显的 .更多还原

【Abstract】 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.更多还原