Abstract: Full waveforms of acoustic emission(AE)events were recorded during uniaxial compression of rockmass specimens with different structures. AE b-value of every 50 successive AE events was calculated.By scanning all AE events,a curve of b-value dynamic behaviour,i.e. b-value dynamic curve,of each specimen was obtained. According to the variation and evolution mode of b-values and the shape of the curve,two types 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 stable fracture 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 case the term of fracture phase was suggested to describe the fracturing process.

Key words: Acoustic emisslon, b-value, Rock deformation, Rupture process

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AE b值动态曲线;根据变化幅度和演化方式,将AE b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AE b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。

关键词: 声发射, b值, 岩石变形, 破裂过程