Deformation and Failure Mechanisms and Control Technology of Surrounding Rock in High Stress Coal Tail Road

Aiming at the control problem of surrounding rock in high stress coal inner interlocked tail road of the isolated fully-mechanized caving face, combining with the field investigation, numerical simulation, theoretical analysis, and field monitoring, the deformation failure characteristics of surrounding rock are analyzed. The results show that plastic zone in roadway's sides extended constantly is the root of roof convergence and floor heave during un-mining influence period and lack of the pre-support is the main reason of rib spalling and roof caving. Accordingly, the support theory and technology of "roof support-floor control-ribassist" are proposed, that is, a row of the sectional block-type concrete pillars will be installed in the inner interlocked tail road in order to support roof forcefully and floor heave is controlled through roof press transferred to floor by the sectional block-type concrete pillars, at the same time, the load of two ribs is reduced so that plastic zone in two ribs is prevented from expanding to the deeper coal mass, and the concrete pillars play role of the fore support during mining influence.