<<
[an error occurred while processing this directive] | [an error occurred while processing this directive] >>
Study on the Influence of Different Degrees of Leakage on Long-term Settlement of Shield Tunnels
(1. State Key Laboratory of Building Safety and Built Environment, Beijing 100013; 2. Foundation Engineering Research Institute of China Academy of Building Sciences,Beijing 100013; 3. School of Civil Engineering, Xuzhou University of Technology, Xuzhou 221018;4. School of Civil Engineering, Zhengzhou University, Zhengzhou 450001; 5. Wuhan Metro Group Co., Ltd.,Wuhan 430070; 6. School of Architectural Engineering, Chang′an University, Xi′an 710061)
Abstract To address the increasingly prominent long-term settlement problem of shield tunnels in soft soil areas, the Shanghai Metro Line 2 project is used as the study case. Considering the coupling of soil consolidation and seepage, the long-term settlement pattern of tunnels in viscoelastic soil under different seepage conditions after construction disturbance is studied by using FLAC 3D numerical simulation method. And the influence patterns of different degrees of water seepage on the dissipation of excess pore pressure in the soil around the tunnel, pore pressure distribution,and long-term settlement of the tunnel and ground were comprehensively analyzed. It was found that when tunnel lining leakage occurs, the excess pore water pressure dissipates continuously with the growth of time, and the dissipation rate becomes gradually smaller with the distance to the tunnel from near to far. The larger the relative permeability coefficient, the stronger the permeability of the tunnel lining, and the more obvious the reduction of its pore pressure after the same time; tunnel settlement continues to increase with time, the larger the relative permeability coefficient, the greater the tunnel settlement at the same moment, and the greater the curvature of the ground settlement trough formed.
Abstract：
To address the increasingly prominent long-term settlement problem of shield tunnels in soft soil areas, the Shanghai Metro Line 2 project is used as the study case. Considering the coupling of soil consolidation and seepage, the long-term settlement pattern of tunnels in viscoelastic soil under different seepage conditions after construction disturbance is studied by using FLAC 3D numerical simulation method. And the influence patterns of different degrees of water seepage on the dissipation of excess pore pressure in the soil around the tunnel, pore pressure distribution,and long-term settlement of the tunnel and ground were comprehensively analyzed. It was found that when tunnel lining leakage occurs, the excess pore water pressure dissipates continuously with the growth of time, and the dissipation rate becomes gradually smaller with the distance to the tunnel from near to far. The larger the relative permeability coefficient, the stronger the permeability of the tunnel lining, and the more obvious the reduction of its pore pressure after the same time; tunnel settlement continues to increase with time, the larger the relative permeability coefficient, the greater the tunnel settlement at the same moment, and the greater the curvature of the ground settlement trough formed.
LI Xiangyu1,
2 LI Xinyuan3 LI Mingyu4 YANG Xiao5 HUANG Pei6
.Study on the Influence of Different Degrees of Leakage on Long-term Settlement of Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(5): 72-79
2022, Vol. 59 