Abstract In this paper, using a shield tunnel in water-rich sandy ground as the study object, a mechanical model of shield thrust is established, with a focus on five influential factors, i.e., front additional thrust, friction force between the cutterhead and soil mass, friction force between the shield shell and soil mass, ground loss, and synchronous grouting pressure at the shield tail. Based on the Mindlin solution, a 3D analytical solution to ground deformation, which considers the influence of synchronous grouting pressure and cutterhead friction force, these factors are derived and verified by in-situ monitoring data and numerical analytical results. Analytical results show that curve of transverse ground deformation by shield tunneling presents in a "V" shape and the curve of the longitudinal deformation is an "S" shape, the left and right sides of the ground deformation curves concerning the friction force between the cutterhead and soil mass are antisymmetric, and ground heaving may occur due to synchronous grouting pressure at the shield tail and can be effectively controlled in time by grouting under the appropriate grouting pressure. The results obtained from this study are reasonable and suitable for predicting ground deformation during shield tunnelling.
Abstract：
In this paper, using a shield tunnel in water-rich sandy ground as the study object, a mechanical model of shield thrust is established, with a focus on five influential factors, i.e., front additional thrust, friction force between the cutterhead and soil mass, friction force between the shield shell and soil mass, ground loss, and synchronous grouting pressure at the shield tail. Based on the Mindlin solution, a 3D analytical solution to ground deformation, which considers the influence of synchronous grouting pressure and cutterhead friction force, these factors are derived and verified by in-situ monitoring data and numerical analytical results. Analytical results show that curve of transverse ground deformation by shield tunneling presents in a "V" shape and the curve of the longitudinal deformation is an "S" shape, the left and right sides of the ground deformation curves concerning the friction force between the cutterhead and soil mass are antisymmetric, and ground heaving may occur due to synchronous grouting pressure at the shield tail and can be effectively controlled in time by grouting under the appropriate grouting pressure. The results obtained from this study are reasonable and suitable for predicting ground deformation during shield tunnelling.
JIANG An-Long
.Analysis of the Influential Factors of and 3D Analytical Solution for Ground Deformation Induced by Shield Tunnelling[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(1): 127-135
2015, Vol. 52 