地震前兆时空非均匀性指标C_v值的实验检验

EXPERIMENTAL EXAMINATION ON THE HETEROGENEITY PARAMETER C_v OF DISTRIBUTION OF EARTHQUAKE PRECURSORS

在双向加载条件下 ,对两种构造和介质不同的岩石标本进行变形实验 ,测量了标本表面不同部位的应变 .在此基础上 ,利用王晓青和陈学忠等提出的描述地震前兆非均匀分布的参量—— Cv 值 ,分析了标本变形失稳过程中应变异常的分布 ,以期从实验角度检验 Cv值方法并探讨其物理意义 .研究表明 ,Cv值的变化与岩石变形特征的变化有关 ,是描述前兆分布非均匀性的一种有效指标 ;Cv值在失稳发生前先异常上升 ,然后下降 ,并在 Cv值恢复过程中或恢复后伴随着失稳事件的发生 .因此 。

Two rock samples with different structure and materials were deformed under a biaxial loading system, and multipoint strain measurements were performed for each sample. The distribution of strain anomalies during the deformation and the instability process was analyzed by using C v value put forward by Wang Xiaoqing and Chen Xuezhong, et al , a parameter to describe the heterogeneous distribution of earthquake precursors, to examine the method of C v value and to explore its physical meaning experimentally. The result shows that the change of C v value is correlated to the change of deformation characteristics and is an effective parameter to describe the heterogeneity of precursor distribution. C v value increases firstly and then decreases before the instability, and the instability occurs when C v value decreases to the level before increasing. This indicates that C v value may be a useful parameter for earthquake prediction.