MEASUREMENTS OF THREE-DIMENSIONAL DISPLACEMENTS OF SLOPE GENERATED DURING LARGE ROCK MASS EXCAVATION

Three-dimensional displacements during large rock mass excavation were measured using a three-components underground inclinometer. From these, a vertical deformation (rebound), a horizontal deformation, a convergence time and a trend of non-linear increase of vertical strain by a removed load were clarified. And a practical elasticity coefficient was estimated by a removed load of excavation and a vertical deformation. Furthermore, the relation between a removed load process of a borehole lateral load test carried out before excavation and an elasticity coefficient was investigated. Based on these studies, the method of developing analytical model using a data of borehole lateral load test carried out before excavation and the risk control criteria during excavation were proposed.