The shield tunnel is fundamentally an assembled structure, and its mechanical response during operation determines structural damage development and service performance. Therefore, a clear understanding of its mechanical response is essential before studying the damage development patterns of shield tunnels. Due to the interaction between "surrounding rock-structure," the mechanical response of shield tunnels is closely related to geological conditions. Additionally, different external loads lead to different responses. Existing research in this area still has certain deficiencies, especially concerning different overburden conditions and less attention to underwater shield tunnels. Moreover, existing monitoring methods lack efficient wireless transmission means, leading to mutual interference between monitoring operations and construction operations, resulting in low efficiency.
To address the above issues, the research team conducted the following work: (a) Based on actual engineering, the study revealed the development patterns of bending moments and convergence deformations of adjacent tunnels under different overburden depths during close-range construction of twin-tube shield tunnels. It focused on the influence mechanisms of excavation face support and tail grouting operations on internal forces of adjacent tunnel structures; (b) Regarding the dynamic response of underwater shield tunnels under strong earthquake action, detailed finite element simulations were conducted. It clarified that joint opening within the permissible safety limits under 0.2g strong seismic waves, and the lining deformation mode depends on the propagation direction of seismic waves; (c) Based on actual subway tunnels, the research investigated wireless sensor network technology in the monitoring of shield tunnel mechanical responses. It established the conversion formula between the tilt angle variation of inclinometers and the horizontal convergence of the lining rings. The optimal installation position for inclinometers in the installation section was derived. By combining finite element simulations, an optimized reconstruction strategy for shield tunnel wireless sensor network layout was proposed, effectively improving the utilization efficiency of wireless sensors in confined and elongated tunnel spaces.
Students: Mr Zhuohua Peng (2018 intake, 2021 graduated), Mr Linhong Fang (2020 intake, 2023 graduated)
Collaborator: Dr Shuang Zheng (CSCEC4 Civil Engineering Co. Ltd)