Abstract: In this paper, two simulated material models, one contains some initial joints and another contains no initial joints, are employed to investigate systematically the influence of initial joints on the surface subsidence. Moreover, within the framework of damage mechanics,the influence and effect of initial joints on the surface subsidence are investigated, and the empirical relation between the characteristic value of surface subsidence and damage variable is obtained

Key words: jointed rock, surface subsidence, characteristic value of surface subsidence, damage variable