Research On Nonlinear Dynamics Characteristics Of Rock And Rockburst In Coal Mine

Rockburst is an abrupt dynamics phenomenon which endangers coal mine. With the increase of excavation depth, it is more and more severity. The key problems still exist though lots of studies were made by scholars and technicians. Because of the nonlinear behavior of coal and rock in mine, rockburst is a greatly complex system and the essence of rockburst are nonlinear characteristics. So it is difficult for traditional theories to explain and solve these problems. On the other hand, new theories and methods to settle these matters were applied by modern nonlinear science based on self-organization, fractal, catastrophe, bifurcation, chaos and artificial neural network. Therefore, it is possible to obtain greater breakthrough for the research of rockburst with modern nonlinear science. According to the CT real-time testing, self-organization, fractal, catastrophe, chaos and artificial neural network were used in this thesis. The main contents of this thesis are as follows: 1) The CT real-time testing of coal under uniaxial compression was carried out. The behavior of microscopic was analyzed. The characteristics of bifurcation, chaos and self-organization in the testing were obtained.2) According to the results of the CT real-time microscopic damage propagation testing of coal and the define of damage variable, the constitutive model and evolution function of coal under uniaxial compression were put forward. 3) The mechanism of stick-slip to rockburst was put forward in this thesis. The phase plots and evolution of rockburst system were analyzed particularly with the Single State Variable Model (SSVM) and Tow State Variables Model (TSVM). The characteristics of chaos in rockburst and the dynamics behavior of failure in coal were studied completely in this paper. 4) On the basis of practice instances in Yanshitai coal mine, the process of rockburst is studied with catastrophe in the modern nonlinear science through the establishment of geology model and mechanics model of rockburst in Yanshitai coal mine. The stress threshold when rockburst took place, the distortion value and the expression of energy in rockburst were obtained.5) In view of the realistic conditions in Yanshitai coal mine of Nan Tong mining bureau, rockburst is researched carefully with factual and self-organization. The research shows: fractal dimension is an useful method to rockburst, the scale and the frequency ofrockburst accord with Power Law which has obvious self-organization characteristics.6) The new method of rockburst prediction were put out on the basis of BP artificial neural network and genetic algorithm in the realistic conditions in Yanshitai mine. The object-oriented software of BPAGA TOOLS was designed which achieved better results in rockburst prediction. It was a new approach with higher reliability to ruckburst prediction...