Mechanism and Control Technology of Floor Heave at Return Airway at Fully Mechanized Caving Face

In order to effectively solve the problem about floor heave of rectangular roadway in changcun Coal Mine, by analyzing the deformation mechanism and failure characteristics of surrounding rock of roadway, we propose two schemes including drillhole pressure relief and drillhole pressure relief + inverted arch of the concrete + floor anchor. In this article, the change of plastic area and displacement field on two supporting schemes were compared by FLAC^3D numerical simulation. By comparing the pristine roadway deformation, the maximum floor heave amount is 146 mm which is only 23% of the original roadway deformation amount by using the scheme of drillhole pressure relief + inverted arch of the concrete + floor anchor. So, combined supporting method can control deformation of roadway and floor heave effectively.