Multi-indicator and fractal dimensional analysis of acoustic emission information before peak strength of rocks
[Objective]Exploring the acoustic emission precursor properties before rock damage can provide a basis for predicting rock damage.[Methods]Indoor uniaxial compression tests and multi-channel acoustic emission tests were conducted on granite and tuff samples to analyze the number of acoustic emission events,b,A(b),lack of seismicity bL,total area of rupture surface A(t),acoustic emission activity scale ΔF,acoustic emission activity S,and fractal characterization of acoustic energy and spatial location of the event source during the deformation of rock samples in force up to the peak fracture process.[Results]Two results were obtained through experimentation and analysis::(1)The b and lack of seismic bL decreased significantly before the destruction of the rock samples,and low value anomalies appeared;the A(b),the acoustic emission activity S,the acoustic emission activity scale ΔF,and the total area of the rupture surface A(t)increased suddenly before the destruction of the rock samples,and high value anomalies appeared.(2)The acoustic emission energy release and source spatial position evolution during the loading process have good fractal characteristics,and the fractal characteristics of the spatial time series are more obvious than those of the energy time series.[Conclusions]This paper introduces a comprehensive consideration of"time-space-intensity"parameters and statistically significant indicators with clear physical meanings,which can effectively characterize the acoustic emission characteristics prior to rock failure,thus providing a solid foundation for further research on rock failure prediction.
rock failureacoustic emissionfranctalal dimensioncorrelation
万方数据
维普
