Abstract
Kishima-group mudstone caused inner displacement in Tawarazaka tunnel. The inner displacemenat is characterized by squeezing.
In order to be safe and efficiency, it was proposed appropriate selection of tunnel supports and pilot core boring. The tunnel supports are get a high support structure and early closure. The pilot core boring help estimation of ahead geology.
In this paper report the tunnel method such as early closure and pilot core boring in squeezing mudstone.
