岩石破裂扩展过程中的声发射b值动态特征及意义  

AE b-VALUE DYNAMIC FEATURES DURINE ROCKMASS FRACTURING AND THEIR SIGNIFICANCES

作　　者：曾正文[1] 马瑾[1] 刘力强[1] 刘天昌[1] 

机构地区：[1]国家地震局地质研究所

出　　处：《地震地质》1995年第1期7-12,共6页Seismology and Geology

基　　金：中国科学院地质研究所工程地质力学开放研究实验室课题;国家地震局八五攻关项目

摘　　要：利用多道声发射（ＡＥ）采集系统记录了不同构造的岩石试件变形破坏过程中的ＡＥ全波形，由扫描算法求得试件变形全过程的ＡＥｂ值动态曲线；根据变化幅度和演化方式，将ＡＥｂ值曲线分为山脊线状和台阶状两类；经与应力－应变时程曲线及试件破裂特征对比，发现山脊线状和台阶状ＡＥｂ值曲线分别对应于较均匀岩石试件的渐进式稳态破裂扩展和含扁平状非均匀构造岩石试件的突发式失稳破裂扩展，后者的破裂状态及其转变可用破裂相和相变来描述。Full waveforms of acoustic emission（AE ）events were recorded during uniaxial compressionof rockmass specimens with different structures. AE b-value of every 50 successive AE eventswas calculated．By scanning all AE events，a curve of b-value dynamic behaviour，i．e. b－valuedynamic curve，of each specimen was obtained. According to the variation and evolution mode of b-values and the shape of the curve，twotypes of b-value dynamic curve，the hill－shaped and the step－shaped，have been distinguished.The hill-shaped b-value curves occured in intact specimens and correspond to progressively stablefracture and propagation. The step-shaped b-value curves tookplace in specimens with planar dis-continuities or heterogeneities，showing abruptly unstable fracture and propagation. In this casethe term of fracture phase was suggested to describe the fracturing process.

关 键 词：声发射 B值 岩石变形 破裂过程 地震 

分 类 号：P315.1[天文地球—地震学]