Top-coal deformation control of gob-side entry with narrow pillars and its application for fully mechanized mining face

A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution of top coal roof-sag curve is deduced with Winkler elastic foundation beam model. By means of a calculating and analytic program, the top coal roof-sag values are calculated under the conditions of different supporting intensities, widths of narrow pillars and stiffness of top coal; meanwhile, the relationship between the roof-sag values and supporting intensity, width of narrow pillars and stiffness of top coal is analyzed as well. With the actual situation of the gob-side entry taken into consideration, the parameters of top-coal control are determined and a supporting plan is proposed for the top-coal control,which is proved to be reliable and effective by on-site verification. Some theoretical guidance and advice are put forward for the top-coal deformation control in gob-side entry for fully mechanized top-coal caving face.