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为了研究地表塌陷型裂缝发育与地质采矿条件之间的关系,在对开采造成的地裂缝进行分类统计的基础上,针对塌陷型地裂缝,运用基于薄板理论的基本顶“O-X”破断原理,结合岩层控制的关键层理论,分析了薄基岩浅埋煤层开采造成的地表塌陷型裂缝的形成机理,研究了塌陷型地裂缝的动态发育规律,并通过工程实例,验证了模型的可靠性。研究表明,在基岩采厚比小于30的情况下,裂隙带直达地表,容易形成地裂缝,若基本顶以上不存在关键层,塌陷型地裂缝伴随着基本顶的破断同时发育,其形态与基本顶破断的“O”型圈形态相似;若存在关键层,受岩层破断角的影响,则会使塌陷型裂缝滞后于煤层开采进度,即存在塌陷型地裂缝滞后角,关键层到基本顶的距离越大,其值越大。
In order to study the relationship between the development of surface subsidence fractures and geological mining conditions, based on the classification and statistics of ground fissures caused by mining, the basic roof “OX ” breaking principle , The formation mechanism of surface subsidence cracks caused by the mining of shallow coal seam with thin bedrock is analyzed in combination with the key layer theory of rock control. The dynamic development law of subsidence ground cracks is studied. The reliability of the model is verified through engineering examples. The results show that when the thickness ratio of bedrock is less than 30, the fractured zone leads to the earth’s surface easily, and the formation of ground fissures is easy. If there is no critical layer above the basic roof, the collapse-type ground fissures develop simultaneously with the rupture of the basic roof. If the key layer is affected by the rock breaking angle, the collapse crack lags behind the coal seam mining progress, that is, there exists the lag angle of the collapsible ground fissure. The key layer to the key layer The greater the distance of the basic top, the greater its value.