Abstract: There are a large number of long deep-buried tunnels either being designed and under construction in Western China. The mechanisms of rockburst hazards and their monitoring and early warning in those deep-buried tunnels are particularly important. Microseismic (MS) monitoring, as a spatial monitoring technology for microcrack initiation and propagation, plays a vital role in predicting and warning rockburst in underground caverns. However, the application of evolution of MS source parameters to assess rockburst hazards has not been efficiently applied in practical projects due to the problems of discreteness (spatial), fluctuation (temporal) and deviation of measured MS data. To improve and solve these problems properly, this paper establishes an EMS method to evaluate and predict rockburst hazards, based on three commonly used source parameters (i.e., seismic energy, the seismic moment and apparent stress) which can be easily obtained and closely interrelated. This method fully defines the concepts of evaluation parameters, such as seismic energy, seismic moment and apparent stress, and thus the relationship among these three parameters can be obtained. Then, these three parameters are applied to predict rockburst and to evaluate the grade of potential rockburst. Meanwhile, the method defines concepts of MS path and the space of MS source parameters. Finally, the EMS method is adopted to analyse a rockburst case in the Micangshan tunnel of Bazhong-Shaanxi highway, Southwestern China. The progressive fractures and rockburst accompanied by MS events are detected and analysed, which achieves an efficient way for daily analyses of MS data and rockburst prediction.

Key words: rock mechanics, microseismic monitoring, microseismic source parameters, rockburst evaluation, rockburst warning