Study on Chaotic and Multifractal Characteristics of Dynamic Outburst Precursor
Coal and gas outburst is a very complex dynamical phenomenon of coal/rock containing gas induced by excavating activities. It can also be regarded as the catastrophic behavior of a complex nonlinear dynamical system during its spatio-temporal evolving process, obviously all the outburst precursors are the physical responses to such nonlinear dynamical process. As one of the main outburst precursors, the dynamic time series of gas emission from excavating face, named as Q series in short, was studied by applying chaos and fractal theories in this paper. Through analyzing the largest Lyapunov exponent, the second-order Renyi entropy and the correlation dimension of Q series, it is verified that Q series possesses chaotic and fractal characteristics. Further study of the multifractal characteristics of Q series shows that when there exists outburst danger at the excavating face, the multifractal spectrum Dq of Q series is remarkably different from that while there is no outburst danger. When there is outburst danger, the curve of Dq vs q obviously appears steep near the point that q equals zero. On the contrary, when there is no outburst danger, the curve of Dq vs q varies gently. Consequently it is indicated that while there exists outburst danger, the evolution of the dynamical system of coal/rock containing gas is more complicated, so that it can be expected that the study will provide a new approach to outburst prediction.
coal and gas outburst dynamic precursor gas emission time series chaos multifractal
WANG Kai WANG Yibo
School of Mining and Safety Engineering, China University of Mining and Technology, Xuzhou 221008, J School of Safety Engineering, North China Institute of Science and Technology, East Yanjiao 101601,
国际会议
The 2007 International Symposium on Safety Science and Technology(2007采矿科学与安全技术国际学术会议)
河南焦作
英文
2720-2725
2007-04-17（万方平台首次上网日期，不代表论文的发表时间）