|
Abstract A single rotary rock block model with the revised step voussoir beam was proposed and a formula calculating the working resistance was established. For the roof structure of the shallow fully-mechanized face，i.e.，31201 working face of Shigetai coal mine in Shendong mining area，three different conditions according to the overlying coal seam which was the solid coal，or the room and pillar goaf or the concentrated pillar in room and pillar goaf were considered so that the roof structures were proposed as a voussoir beam-single rotary rock block，a slight dislocation voussoir beam-single rotary rock block and a severe dislocation voussoir beam-single rotary rock block respectively. The mechanical model of the single rotary rock block was used to calculate the working resistance of support under different roof conditions in Shigetai coal mine. The results showed that the working resistances calculated with the model in different roof structures were correct and the crushing accident of the support cannot be avoided by increasing the working resistance only.
|
|
|
|
|
|
2015, Vol. 34 
