In this paper the instability-failure process of floor due to confined water inrush is numerically simulated by using the Coupling Syst em of Flow & Solid in Rock Failure Process Analysis(F-FRPA2D) that has be en recently developed by CRISR,Northeastern University.In this numerical model t he fluid pressure transmission during the rupture-failure process of material i s achieved by the coupling and iteration of flow-damage of an element.According to the results of the simulation the instability-failure...