Characteristics of Mining Floor Deformation and Failure for Fully Mechanized Top Coal Caving Face in Chaohua Coal Mine

In order to research the deformation and failure of the three-soft coal mining floor in Chaohua Coal Mine in Zhengzhou mining area, taking the 22121 (east) fully mechanized top coal caving face for example, the depth of deformation and failure and variation regular of the rock-controlled strata combination structure are systematically researched on the mining floor in 22121(east) working face under the underground pressure by numerical simulation. Thick soft coal seam, soft roof and soft floor have an important buffer affection for dissemination of stress and deformation, and the deformation and failure of mining floor only occurred in a certain shallow range under the normal condition. An important controlling function is revealed on linestone groups (L7-8) of middle section to the stress distribution and deformation and failure. Finally, the results of two methods are basically coincident by correlative comparative analysis between numerical analysis and site measurement, and as a result it can make good use of variation process of the stress and deformation with depth by numerical simulation to partly explain the mechanism of site measurement, which can be used as the partial mechanics basis for prevention and cure of floor water for the mining coal to the depth in the west of Henan province.