Abstract
From the experience with tunneling, it has been suggested how to mobilize groundarch in surrounding rock. It can be obtained by controlling a loosening zone, which is considered as the post-peak behavior of rock. Focused on the elastic and non-elastic behaviors of rock in tunneling, the authors investigated over 500 convergence curves observed in six tunnel projects through shale and sandstone, granodiorite and slate layers. In conclusion, the allowable limit of deformation should not exceed beyond the range of strain-softening, and should be smaller than 0.5-0.8 % in tunnel diameter so as to mobilize a potential bearing capacity ofsurrounding rock.
