Predicted and Measured Tunnel Face Behaviour During Shield Tunneling in Soft Ground

摘要

This paper presents a study of the tunnel face behaviour during shield tunnel construction,rnconcentrating on the study of the short-term stability of the tunnel face in soft ground encounteredrnunder the riverbed in Korea. The design concept and the strong influence of construction proceduresrnare demonstrated and evaluated based on the predicted and measured tunnel face behaviour duringrnshield tunnelling in two different sites having different ground conditions and tunnel sizes. Anrnimportant feature of these case studies is to investigate the influence of tunnel face behaviour due tornsoil type, tunnel size, and construction procedure in Korea.rnFor each site, the stresses and pore pressures induced at the tunnel face, and the shield headingrnpressures with cutter torques measured during tunnel advance are investigated, discussed andrncompared.rnThe paper also presents and discusses the approach methods for estimating the stability of therntunnel and its heading during drained and undrained condition. In practical, the undrained analyses ofrnthe tunnel face stability for shield tunnelling in the sites are carried out based on the field datarnmeasured during tunnel construction and the results are also evaluated.rnAccording to the results presented in the paper, the future programme to be developed technically isrnsuggested in order to provide a practical knowledge for soft ground tunnelling in Korea.