THREE-DIMENTIONAL EXCAVATION ANALYSES FOR EFFECTS OF ROCK REINFORCEMENT BY MEANS OF LONG FACEBOLTING

In Takadayama-tunnel, the long facebolting by means of the friction anchored rockbolts is adopted as the stabilization measure against face collapse. In order to estimate the effects of rock reinforcement with long facebolts, we measured the axial forces of long facebolts during excavation .Numerical simulation of the measured axial forces was performed by means of three-dimensional excavation analyses; and it successfully expressed the behaviors of measured axial force distributions of the facebolts as well as other tunnel measurements. Furthermore, the numerical analyses with and without facebolts were performed so as to investigate the reinforcing effects.