During the construction of shie ld tunnels，support pressure is usually applied at the work face to prevent Y\WVkd(+G
excessive tunneling—induced soil movement or collapse．However，the selection and control of appropriate support ~piE$"]&
pressure is difficult due to variation of soil conditions and uncerlainty in construction．Support pressure should be
!bCL/[
controlled SO that it is not SO low as to cause face collapse and not SO high as to induce ground hogging．Numerical =nc;~u|]
simulation is employed to study how the soil parameter and ground water affect the support pressure，and to give the
<#57q%
proper support pressure at the excavation face in a case study．
T3<1{"&
Keywords：shield tunnel；excavati‘on face；numerical solution；support pressure
