During the construction of shie ld tunnels，support pressure is usually applied at the work face to prevent $wn0oIuW
excessive tunneling—induced soil movement or collapse．However，the selection and control of appropriate support $ U7#3-'
pressure is difficult due to variation of soil conditions and uncerlainty in construction．Support pressure should be (AX$S vw
controlled SO that it is not SO low as to cause face collapse and not SO high as to induce ground hogging．Numerical -$X4RS
simulation is employed to study how the soil parameter and ground water affect the support pressure，and to give the 3 /PvH E{R
proper support pressure at the excavation face in a case study． h#c7v !g
Keywords：shield tunnel；excavati‘on face；numerical solution；support pressure
