| As we know, traditionally, it is very difficult for researchers and engineers to analyze and deal with rockbursts due to its extreme complexity. However, as an instantaneous and instable phenomenon, it still suffers from the typical rock failure process—the initiation, propagation and coalescence of micro-fracture. Therefore, it is of great importance and necessity for us to predict the rockbursts by investigating the complete process of rockbursts. The research of unloading rockburst covers no long time,but it has been paid more attention in this field. It has been found during observation and researches that the tension near the surface is redistributed and converges induced by unloading in the rock slope and hard rockbody, and the confining tension is builded in the rock body because of the diffenent rebounding tension during the unloading transmutation. The loading test is carried while the research of the rock mechanism about the rockburst was going on.But these doesnot coincide with the stress path.So the unloading test must be done. The chief work of the dissertation is in the following:1. The numerical simulation research of the failure process on the pillar model which belongs similar parameters will be carried out. In this part, the sudden confining loaded and the gradual confining loaded are the major jobs, and the comprison between the former two processes and the later one is to be done. The inffluence of the pillar failure leaded by loading confining pressure is to be analyzed among the mode of the failure,the stress and strain curve and the stress and step curve.2. Under the different axial pressure, the laneway is to be excavated in a rock model owning the same parameters. So it can endow the different stress field to the laneway. Then, the inffluence to the laneway induced by excavation is observed. And the influential mechanism it to be analysed between them from the failure model, the change of stress in the laneway periphery. |
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