Tunnel Stability Control

Tunnel stability should be estimated and expressed by two curial points, tunnel deformationand stress distribution of rock mass around tunnel, through theoretical studies(Gioda, G.and Locatelli, L., 1999; Sterpi., D., 1999; Kim, Sang-Hwan, 2003) and many case studues(Song et al., 2002; Wang,Yi-Wan,2001) on tunnel deformation analysis until the recent. For the first point, some hybrid analysis was proposed by a conjugated method about the critical strain analysis by Sakurai(1988,1990,1997), 3D numerical simulation, field measurement on tunnel excavation, and stability analysis of stress-strain relation based on elastic theory.For the second point, recently successful cases on tunnel excavationin South Korea were introduced. Also, as an new approach about 2 arch conventional tunnel, positive effects of pre-supporting system were respectively introduced relating to the conventional method. Thekey items about the utilization of field measurement on tunnel coustruction and the choice of tunnel excavation methodon primary design were conclusionally summaried and suggested.