Floor Heave Mechanism and Prevention and Control Measures for Shallow Soft Rock Roadway

Aiming at the serious floor heave problem of 2^# coal seam track roadway in Xindingtai Coal Mine,based on the deformation and failure mechanism of roadway and surrounding rock, the factors affecting the floor heave were analyzed,then the floor heave was considered as extruding and flowing type,tectonic stress and the physical properties of surrounding rock and support program are the main factors for floor heave.Combined supporting plan of anchor net-double U29 type steel annulus support was proposed.The blot and the cable were separately used to control shallow and deep surrounding rock in order to form load beam.Double U29 type steel annulus support has overall uniformly bearing and yielding advantages and can form "strong-weak-strong" structure.The surrounding rock was effectively controlled and floor heave reduced by 75%,so the combined supporting plan could meet the normal production requirements.