Abstract
At present, the standard support system in tunnelling of Japan Highway Public Corporation basically consists of five patterns. In practice, tunnelling support is adopted among them. But, adapting only five patterns is not rational because of complicated geological structures. As a result, displacements is numerically almost small in a monitoring, so probably oversupport is adopted. For these reasons, the authors made a plan about reduction of support systems, and detail monitoring and observation of rock mass are executed in several tunnels.
In this paper, the authors report results concerning effectiveness of support system, the effect of each support and several classification systems of estimating quantative rock mass.
