关键词: 岩爆, 板裂屈曲, 最小势能原理, 极限挠度, 破坏深度

Abstract: Slab buckling rockburst is a common rockburst failure mode in high geostress areas. In view of the shortcomings of the existing mechanical models, such as neglecting the interaction between the split rock plates, a thin plate mechanical model of circular tunnel considering the horizontal stress between rock plates is established. The bending deflection of rock plate under load is calculated using the principle of the minimum potential energy, and compared with the ultimate deflection of tensile failure, thus the depth of rockburst failure is yielded. The research rationality is validated through the comparison between the calculation results of the new model and existing models by analyzing an engineering case. The results show that the rock plates around the tunnel are subjected to larger loads and smaller plates thickness. Moreover, the bending strain energy of rock plates is close to the work done by the longitudinal loads, and the buckling failure of the plates can be triggered by small inter-plate forces. With the increase of the distance from the tunnel wall, the thickness of rock plates increases and the stress decreases. The bending deflection of rock plate decreases faster than the ultimate deflection. After reaching a certain depth, the bending deflection becomes less than the ultimate deflection. As the buried depth increases, both the stress and bending deflection of each rock plate experience increase. The number of damaged rock plates also increases as well as the depth of rockburst.

Key words: rockburst, slab buckling, principle of minimum potential energy, ultimate deflection, damage depth