地震非均匀度物理意义的实验研究  

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

作　　者：李志雄[1] 马胜利[2] 李圣强[1] 李闽峰[1] 路鹏[3] 陈华静[4] 王松[4] 吴婷[1] 

机构地区：[1]中国地震局地震预测研究所,中国北京100036 [2]中国地震局地质研究所地震动力学国家重点实验室,中国北京100029 [3]防灾技术高等专科学校,中国河北三河燕郊065201 [4]中国地震台网中心,中国北京100036

出　　处：《地震学报》2005年第6期682-690,共9页Acta Seismologica Sinica

基　　金：国家"十五"科技攻关项目(2004BA601B01)资助.

摘　　要：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．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-Ⅲ 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 nucleation 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 sample＇s fracture.

关 键 词：地震非均匀度 岩石实验 声发射 非弹性变化 地震预测 

分 类 号：P315.61[天文地球—地震学]