Yong-Xia Wu

Factors Influencing the Longitudinal Deformation of a Metro Tunnel in Soft Deposit: An Overview

The Quaternary deposits in coastal regions are multi-aquifer-aquitard system with characteristics of high compressibility, high sensitivity, and low shear strength. The metro tunnels have been widely constructed in coastal regions in recent years. The tunnel settles continuously since the metro tunnel operated. This paper gives a general introduction to influencing factors on the longitudinal deformation of metro tunnel in soft deposit in coastal regions of China: (i) regional land subsidence; (ii) shield tunnel construction; (iii) construction of nearby engineering, such as pit excavation, construction of pile, construction of bypass tunnels, etc; (iv) groundwater leakage; (v) dynamic loading of trains. Influence of land settlement, groundwater leakage and train loading is long-term and influence of tunnel construction and disturbance from the adjacent construction is short-term. Since all of these factors interact with each other, the longitudinal deformation of the tunnel is caused by the comprehensive action of the aforementioned factors.