Author:
Qiang Sihan,Zhao Lizhi,Wang Xuehai,Li Xiaoming,Wang Fengnian
Abstract
The stability of the tunnel face is the key problem in shield tunnel construction. This paper focuses on the face stability of a shallow tunnel in sand. Numerical simulation and theoretical analysis are combined to study the limit support pressure and failure zone. Firstly, numerical simulation is employed to study the collapse of the tunnel face, obtaining the limit support pressure and collapse zone. A new failure model suitable for shallow tunnels is constructed based on these numerical simulations. Then, an analytic solution for the limit support pressure is derived using limit analysis upper bound theory. The accuracy and applicability of this proposed model are verified by comparing it with numerical results and classical analytical models. Through this research, it is found that the proposed model provides a more accurate description of situations where soil arches cannot be formed for shallow tunnels in sand, leading to higher accuracy in calculating the limit support pressure. The influence of various factors on stability of the tunnel face is analyzed, revealing mechanisms of tunnel face collapse.
Subject
General Earth and Planetary Sciences
Reference39 articles.
1. The face stability of slurry-shield-driven tunnels;Anagnostou;Tunn. Undergr. space Technol.,1994
2. Face support for a large mix-shield in heterogeneous ground conditions;Arthur
3. Centrifugal model tests on shallow tunnels in sand;Atkinson;Tunn. Tunnlng.,1977
4. Shallow tunnels in cohesionless soil: stability of tunnel face;Chambon;J. geotechnical Eng.,1994
5. Face stability analysis of shallow shield tunnels in dry sandy ground using the discrete element method;Chen;Comput. Geotechnics,2011