This paper presents experimental and numerical studies on the closure ratio of tunnel face to reduce pressure and displacement occurring at tunnel face during tunnel excavation. In experimental study, model tests are carried out according to the closure ratio of tunnel face and tunnel depth. Model test results are analyzed and interpreted by numerical calculation in order to verify results obtained from experimental and numerical studies. It is clearly found that tunnel face stability increases with the increase of the closure ratio of tunnel face. The results also show that tunnel face is stable when the closure ratio of tunnel face is larger than 80%. This research will be very useful to develop the economical tunnel face closing system.

This study is a research about cutter bits arrangement of shield-TBM and carried out a scale model test and numerical analysis according to a space of cutter bits. A cutter head pressures and an advance time are measured to be followed by the space of cutter bits with an advance speed through the scale model test. We conducted the numerical analysis to verify the result of the scale model test, and to compare with the scale model test. There are three cases of space : unification 1.0D and 1.5D. In case TBM is excavated and space is 1.0D, the advance speed is much faster than the other cases, and pressure of face of ground deformation and cutter head is maintained stably.

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