Abstract: In response to the floor heave with large deformation of roadway in deep soft rock in Tingnan coal mine, an in-depth study has been done in this paper based on the methods of geological survey, physicochemical test, numerical calculation, in-situ test. The complex deformation mechanism in the west pathway floor heave has been analyzed, and a new technology called “four control and one measure” to transform from the complex deformation mechanism to a simple one has been proposed. In the technology, the roof, two sides, base angle, and floor of the roadway are related to each other as a whole to control the deformation of each position and attain the goal of controlling the floor heave with water control measure. The “four control” includes four countermeasures. First, the anchor bolt is added to the roof and the anchor cable is added to the key position to reduce the stress acting on the floor from the roof. Second, the base angle bolt is used to cut off the plastic slip line of the floor base angle with its own flexural stiffness of the material. Third, the bolts are embedded into the two sides of the roadway to enhance the strength of rock and decrease the width of floor heave. Fourth, the counter-force acting on the inverted arch floor is exerted to bring uniform support and form a closed supporting system. The “one control” includes constructing the drainage in time to avoid the ponding immerging the floor to form floor heave, guniting on the roof and sides to cut off the path of fissure water, and spreading dry lime powder after cutting bottom to close the surrounding rocks of floor. Engineering practice shows that this new technology has effectively controlled the floor heave of soft rock roadway in Tingnan coal mine.

Key words: floor heave, inverted arch, water control measure, numerical simulation