Abstract: In this paper the difference in waves, frequences, and sources mechanism is analyzed by com-paring the characteristics of acoustic emissions in the rock bridge of tensile en echelon structurewith that in the rock bridge of compressive shear structure,or that on main fault so as to revealthe characteristics of acoustic emissions in en echelon structure,The result shows that acoustic e-missions in en echelon structure have several mechanisms. The acoustic emission in the rockbridge of tensile en echelon structure is of one single event,its amplitude of waveform is verysmall with short duration time and higher main frequency,and mechanism of acoustic emissionsbeing tensile. The acoustic emission in the rock bridge of compressive shear en echelon structureis also of single event with larger amplitude of waveform,short duration time and lower main fre-quency,and mechanism of acoustic emissions being compressive shear. But the acoustic emissionon main fault of en echelon structure is of multiple events with largest amplitude of waveform,longer duration time and lowest main frequency,and mechanism of acoustic emissions being com-pressive shear whose direction of fracture is opposite to that of that in the rock bridge of compres-sive shear.

Key words: Acoustic emission, Waveform analysis, Spectrum, Focal mechanism, en echelon fault

摘要： 对拉张型、挤压型雁列断层变形过程中岩桥区和主断层上的声发射特征进行了对比研究,结果表明,雁列断层变形中的声发射对应着多种机制:拉张型雁列岩桥区的声发射为单一事件组成,波振幅小、持续时间短、主频高、震源机制为张裂型;挤压型雁列岩桥区的声发射也是单一事件,波振幅较大、持续时间短、主频较低、震源机制为双剪型;而雁列主干断层上的声发射由多事件组成,波振幅大、持续时间长、主频低、震源机制与挤压型雁列岩桥区的声发射机制不同。这些特点与各区域所处力学状态有关。

关键词: 声发射, 波形分析, 谱, 震源机制, 雁列断层