Mechanism and countermeasures of layered floor heave of large section mining roadway.

In order to study the mechanism and effective countermeasures of floor heave in large section mining roadway, one of its prediction methods was put forward through theoretical deduction. It is showed that floor rock beam with lower critical stress is easier to instability, along with larger section of mining roadway. Almost all large section roadway are subject to the threat of floor heave under horizontal force. Moreover, with the increasing width of tunnel, the heave volume increases approximately linearly. At the same time, three kinds of support scheme, roadway support, reinforcement of sides, comers and roof, were analysed with Ansys. A conclusion is drawn that floor heave can be controlled well by installing roof bolting based on floor on a small scale with the reinforcement of working slope, angle and roof. [ABSTRACT FROM AUTHOR]