Using 3DEC discrete element software,a model of long-span tunnel with different joint distribu-tions is established.Considering the strikes,dip angles,spacing and mechanical parameters of joints,the de-formation and failure of surrounding rocks without support of the long-span tunnel after excavation is simulated and analyzed.The research results show that the risk position of the long-span tunnel surrounding rock after excavation is mainly determined by the strikes and dip angles of the joints.The instability and falling of blocks in this position are determined by the joint spacing and mechanical parameters.When considering the bidirec-tional combination joints,the surrounding rocks are more complex than the unidirectional joints.The deforma-tion and failure forms of the tunnel surrounding rocks not only present a certain laws in the cross section,but also present difference in the tunnel axis.The X-direction joints mainly affect the deformation and failure loca-tion of the tunnel cross-section surrounding rocks,while the Y,Z-direction joints affect the deformation distri-bution laws of the tunnel axis direction,and the larger the joint dip angle,the deeper the surrounding rocks loosening ranges.
关键词
隧道工程/节理岩体/离散元模拟/围岩变形破坏/大跨隧道
Key words
tunnel engineering/jointed rock mass/discrete element simulation/deformation and failure of surrounding rock/long-span tunnel
维普
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