Experimental Study on Floor Heave in Stable Stage of Gob-side Entry Retaining

In order to obtain the mechanism and control countermeasures of floor heave in stable stage of gob-side entry retaining, creep test of post-failure rock is performed to study the impact of damage degree and confining pressure increment on creep properties of post-failure rock. The results showed that: the smaller damage degree of the post-failure rock, the smaller of its creep rate and the longer of its self-stability time; the increase of confining pressure can reduce the practical bearing equivalent stress of the post-failure rock and then improve its creep properties. The paper draws a conclusion that the form of floor heave in stable stage of gob-side entry retaining roadway is creep deformation of post-failure rock in floor fracture region and slippage of displaceable blocks along failure surface.