INVESTIGATION ON BLOCK DISPLACEMENTS DUE TO A SHALLOW TUNNEL EXCAVATION IN AN INCLINED BRICK-TYPE JOINTED ROCK MASS USING DISCONTINUOUS DEFORMATION ANALYSIS

摘要

A tunnel excavation in an inclined brick-type jointed rock mass is simulated by the trap-door tests in this paper. Besides, a discrete analysis method, named discontinuous deformation analysis (DDA), is employed to study the block displacements during tunnel excavations. The simulation results of surface subsidences are in good agreement with the trap-door experiments. According to DDA simulations, the displacements of blocks affect the features of surface subsidences and could be the reason for arching close to the trap-door. In addition, both surface subsidence and arching are strongly affected by the dip angle of the joint. These results demonstrate that DDA could be a powerful method to investigate the behaviors of jointed rock masses during tunnel excavation.