During the construction of shie ld tunnels，support pressure is usually applied at the work face to prevent M0w Uis:`
excessive tunneling—induced soil movement or collapse．However，the selection and control of appropriate support 9\4 x<*
pressure is difficult due to variation of soil conditions and uncerlainty in construction．Support pressure should be k|/VNV( =0
controlled SO that it is not SO low as to cause face collapse and not SO high as to induce ground hogging．Numerical 0vqVE]C
simulation is employed to study how the soil parameter and ground water affect the support pressure，and to give the l+9RPJD/:
proper support pressure at the excavation face in a case study． J\y^T3Z
Keywords：shield tunnel；excavati‘on face；numerical solution；support pressure
