Analysis of ground surface settlement induced by the construction of a large-diameter shield-driven tunnel in Shanghai, China

Abstract

There is an ever-growing demand of construction of large-diameter tunnel in Shanghai, China. How to minimize the environmental impact induced by the tunnel construction has been a hot topic of research over the recent years. The Yingbin San Road tunnel with an external diameter of 13.95m has been taken as an example to elaborate the controlling of ground surface deformation induced by shield-driven tunneling, in the case of tunnel passing through the settlement sensitive area and adverse geological conditions. Tunneling process of the EPB shield machine was simulated using a three-dimensional finite difference method. Parametric study was performed to optimize the construction parameters. Field measurement was also carried out to validate the numerical model and its applicability in the case of large-diameter tunnels. Both the numerical prediction and field test data show that grouting pressure and quality appear to determine the surface settlement rather than the supporting pressure at workface on the premise of guaranteeing the safety of tunneling process. Both the empirical correlations and field observations demonstrate that the volume loss Vi should be controlled below 0.2% to guarantee the maximum surface settlement no more than 10mm in the airport area. However, the empirical predictions of trough width parameter i do not match the field measurement very well except for the case where such a high volume loss as 0.81% was obtained.