QIU Dao-hong, ZHANG Le-wen, XUE Yi-guo, et al. Studies of surrounding rock stress change character and rockburst prediction of underground cavern during stepped excavation[J]. 2011, 32(S2).
QIU Dao-hong, ZHANG Le-wen, XUE Yi-guo, et al. Studies of surrounding rock stress change character and rockburst prediction of underground cavern during stepped excavation[J]. 2011, 32(S2).DOI:
In order to analyze the mutual influence of different layers stresses in the progress of every excavation step and take advantage of the former rock burst situation to predict the rock burst intensity of later layer
numerical calculation and in-site supervision measure are adopted to conduct a series of calculations and analysis. The results show as follows. When horizontal stress and vertical stresses of the initial stress field are equal
the stresses of vault
corner and the floor increase significantly at early period
and smaller increase later
gradually stabilized with the excavation progress. If the former layer rock burst appears
the vault
corner and floor of the later layer rock burst appear too. Cavern excavation has greater risk of rock burst at early period and would be smaller later. When the initial stress field dominated by the horizontal stress
with the ongoing excavation steps
the stress of the vault
corner and the floor have no large increase at early period
but later period changed rapidly. The greater the lateral pressure coefficient is
the greater the rock burst risk of the later layer is in case that the former layer rock burst appears. Finally
it is proved that the correctness of analysis results by comparison with the actual excavation. The results provide a new idea to predict underground cavern stability of later excavation layer by using the interaction among the characteristics of every layer