A platform for research: civil engineering, architecture and urbanism
A simplified method for estimating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation
Abstract The construction of soil excavations will inevitably have an adverse effect on the adjacent tunnels. However, the structural responses of existing shield-driven tunnels adjacent to a braced excavation and their serviceability are still not fully understood. This paper presents a simplified method for evaluating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation. To capture both shear and bending deformation of segmental linings, an appropriate model was adopted to study the longitudinal tunnel deformation features based on the Timoshenko beam theory. A continuous ring structure under a plane strain condition was used to determine the circumferential behavior of segmental lining. Case history was used to verify the developed simplified method. Systematic parametric studies were performed to develop a better understanding of the governing factors of the tunnel behaviors, including excavation-tunnel relative position and the retaining wall deflection. Furthermore, the serviceability limit state of shield tunnels was quantified using the defined three factors of safety, which enables a quick assessment of the excavation-induced tunnel damage potential. The contours of factor of safety can also be employed to determine the envelope of the excavation influence zones.
A simplified method for estimating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation
Abstract The construction of soil excavations will inevitably have an adverse effect on the adjacent tunnels. However, the structural responses of existing shield-driven tunnels adjacent to a braced excavation and their serviceability are still not fully understood. This paper presents a simplified method for evaluating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation. To capture both shear and bending deformation of segmental linings, an appropriate model was adopted to study the longitudinal tunnel deformation features based on the Timoshenko beam theory. A continuous ring structure under a plane strain condition was used to determine the circumferential behavior of segmental lining. Case history was used to verify the developed simplified method. Systematic parametric studies were performed to develop a better understanding of the governing factors of the tunnel behaviors, including excavation-tunnel relative position and the retaining wall deflection. Furthermore, the serviceability limit state of shield tunnels was quantified using the defined three factors of safety, which enables a quick assessment of the excavation-induced tunnel damage potential. The contours of factor of safety can also be employed to determine the envelope of the excavation influence zones.
A simplified method for estimating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation
Cheng, Hongzhan (author) / Chen, Renpeng (author) / Wu, Huaina (author) / Meng, Fanyan (author)
2020-04-11
Article (Journal)
Electronic Resource
English
British Library Online Contents | 2018
|Pile Response Adjacent to Braced Excavation
Online Contents | 2003
|Pile Response Adjacent to Braced Excavation
British Library Online Contents | 2003
|Effects of a deep excavation on an adjacent shield-driven tunnel
British Library Conference Proceedings | 2001
|