Research on Vault Ultimate Displacement at Different Tunnel Construction Stages in Surrounding Rock of Grade Ⅴ
(1 School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031; 2. School of Civil Engineering, Shijiazhuang TieDao University, Shijiazhuang, Hebei 050043; 3 Fuzhou Municipal Construction Development Co., Ltd, Fuzhou 350108;4 Fuzhou Planning Design & Research Institute, Fuzhou 350108)
Abstract：
The existing ultimate displacement and its management reference are mainly determined after the clo?
sure of supporting structure of the common railway tunnel section, without considering the tunnel construction stages.Taking the existing high-speed railway tunnel which locates in surrounding rock of grade Ⅴ and adopts three bench method for example, it simulates the vault displacements in different construction stages by FLAC3D software, obtains the ultimate vault displacements in different construction stages based on cusp catastrophe theory. The results show that the ultimate vault displacements are affected by excavation of upper bench, middle bench, lower bench and invert in decending order and there is almost no effect by lower bench and invert excavation in the case of threebench construction in the surrounding rock of grade Ⅴ; under the calculated buried depth of 50-300 m, the ultimate displacement at vault in the same construction stage has a linear relationship with the buried depth. The sensitivities of surrounding rock parameters to the ultimate displacements are analyzed by grey correlation, and the influence de?
grees on the ultimate vault displacement are rock mass density ρ, elasticity modulus E, cohesive force c, poisson rate μ and internal friction angel φ in descending order.
ZHANG Yiteng1 SUN Xingliang2 JIANG Yongtao1 YU Li1 JIANG Fan3 CHEN Mingyue3 XIAO Zerong4
.Research on Vault Ultimate Displacement at Different Tunnel Construction Stages in Surrounding Rock of Grade Ⅴ[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(4): 91-97
2020, Vol. 57 