关键词: 浅埋煤层, 地表移动变形, 时空特征, 深厚比, 突陷性

Abstract: Based on the statistics and analysis of a large number of documents, the spatial-temporal characteristics of shallow coal seam surface subsidence under fully-mechanized coal mining （fully-mechanized top-coal caving）are summarized, and the mechanism of surface movement is explored. The results show that, when the depth-thickness ratio is less than 40, the unexpected surface subsidence increases, the regular surface subsidence decreases, and it has two iconicity of unexpectedness and continuity, but it still has strong regularity generally. The unexpectedness is mainly manifested by the discontinuity of surface movement in the collapse pit, the collapse trough, the fissure and so on, as well as the occasionality of surface movement lasting time, the sinking quantity and so on. In general, the greater depth-thickness ratio is, surface subsidence continuity is the stronger, the smaller the depth-thickness ratio is, and unexpected surface subsidence form is the stronger. Two view points are put forward according to the study results :（1）under fully mechanized caving （fully-mechanized top-coal caving）, depth-thickness ratio can be used as the surface movement boundary between continuity and discontinuity.（2）under fully mechanized caving （fully-mechanized top-coal caving）, when the depth-thickness ratio is less than 40, the surface movement lasting time can be estimated within 1.85 times of mining depth.