| Rockburst is a violent rock failure process which poses a significant threat to human safety in mining and tunnelling construction. In this thesis, the rockburst behaviour of sandstone affected by its bedding orientation is investigated. A modified triaxial rock testing apparatus is used to create the rockburst boundary conditions. Two parameters, the fractal dimension of mass-frequency distribution of rock fragments and the velocities of ejected fragments, are recommended to define the rockburst severity. The magnitude variations and b-value variations of the acoustic emission signals are used to express the energy transformations during rockburst. In addition, the fractal analysis is induced to show the propagation of microcrack and ruptures on the surface of sandstone specimens in micro-and macro-scale. DDA2D is recommended to simulate the rockburst progress and a new elastic-brittle-perfect plastic model is built for the block deformation. All those results can contribute for the further study of rockburst mechanism. |
PDF Full Text Request