浅埋煤层综采(综放)条件下地表移动变形特征分析

Study on Characteristics of Shallow Coal Seam Surface Subsidence under Fully-mechanized Mining( Top-coal Caving)

在整理统计和分析大量文献资料的基础上,总结了浅埋煤层综采(综放)条件下地表移动时空特征,探讨了浅埋煤层综采(综放)条件下地表移动机理。研究结果表明,深厚比小于40时,地表变形突陷性增大,规律性减弱,具有突陷性和连续性二象性,但总体上仍具有较强的规律性。突陷性主要表现为地表移动形式的塌陷坑、塌陷槽、裂缝等非连续性以及地表移动时间、下沉量等的偶然性。总体上,深厚比越大,连续性越强,深厚比越小,突陷性越强。根据研究结果提出了两个观点:综采(综放)条件下,深厚比40宜作为地表移动连续性的界限;深厚比小于40时,综采(综放)条件下预计地表移动持续时间不超过1. 85倍采深。

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 : under fully mechanized mining( fully-mechanized top-coal caving),depth-thickness ratio can be used as the surface movement boundary between continuity and discontinuity;under fully mechanized mining( 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.