The Study On Chaos Of Rock Burst For Deeply Deposit Exploitation

In the process of deep mining, the stress is redistributed induced by excavation. If the stress is released suddenly, the rock burst occurs possibly. Before the rock burst occours, its own evolution was highly nonlinear complex and irreversibly dynamic. In order to predict and control the behavior of the rock burst, it is necessary to use nonlinear science, and to set up rock engineering nonlinear static and dynamic systems theory suitable for rock mechanics and rock engineering. The chaos was a hot topic of nonlinear mathematics and mechanics. Under the support by Natural Sciense Foundation for Talented Youngs of Chongqing and the Supporting Program of New-Century Talents by the Ministry of Education,the paper based on the acoustic emission monitoring data, the rock burst was predicted by using chaos theory and wavelet theory, and a prediction model was established based on monitoring data, the main coaclusions were summuraized as follows:①Based on geological structure equatorial horizon projection principle, the direction in-site stresses are determined through the X failure. Specimen was picked up in the main roadway in 625 meters depth below ground level. And the value of stress was determined by Kaiser acoustic emission experiments.②In order to improve the reliability of the burst perdiction, wavelet transform was applied to remove the noise of the original monitoring data. By means of the chaotic characters of original, nosing, reduced noising Lorenz series, the feasibility of wavelet noise reduction was determined.③A large number of monitoring acoustic emission series was applied to calculate the delay time and embedding dimension, the delay time was determined by self-correlation function, mutual information and C-C method, and the embedding dimension was determined by Cao method.④Correlation dimension and Lyapunov exponent extracted from the monitoring acoustic emission series. It was revealed from that acoustic emission possess chaotic behavior, which provided the theoretical bais to predict rock burst.⑤Compared one-order approximation model and Lyapunov exponent model with auto-regression model, the prediction result from chaos is accureter than that from statistics.