Segment Stress Responses of Shield Tunnels Caused by Deep Excavations in Improved Soil

Abstract

A case study on an existing tunnel was investigated in Taipei city. Ground improvement was carried out prior to the excavation of a new underpass crossing over the tunnel. Monitoring systems such as strain gauges and convergent points were set up for the tunnel as excavation for the underpass might cause heaving of the tunnel. The real-time monitoring system has proved to be effective in warning and preventing disaster from happening during the excavation process. Finite difference code FLAC was used to simulate the whole construction sequence and good agreement was obtained between the numerical and field measured results.