软弱覆岩下厚煤层综放开采导水断裂带高度计算

Calculation on height of water conducted zone for fully-mechanized top coal caving mining in thick seam under soft and weak overburden strata

为得到蒙东地区无软弱覆岩层地质条件下特厚煤层综放开采导水断裂带的准确测算方法,以神华大雁矿业公司敏东一矿02工作面为例,分别采用煤矿防治水经验公式、"三下"采煤计算公式等方法计算导水断裂带高度;同时,采用FLAC^(3D)软件对煤层顶板覆岩破坏对覆岩导水断裂带发育过程进行模拟,分析了不同推进距离下的导水断裂带发育高度,采用塑性区分布法,得到了导水断裂带发育高度"突变"和"稳定"2种状态与回采工作面的推进距离。经计算,3种方法得到的导水断裂带高度分别为93.12、26.67和88.00 m,而采用现场钻探观测表明导水断裂带高度为83.78 m。实测数据表明,蒙东地区软弱覆岩特厚煤层综放开采条件下冒采比为5,裂采比为11。

In order to get the accurate calculation method of the water conducted zone in the fully mechanized top coal caving mining in ultra thick seam under the geological conditions of the soft and weak overburden rock strata in the east part of Inner Mongolia Area,based on the No.02 coal mining face in No. 1 Mindong Mine of Shenhua Dayan Mining Company as a case,the coal mine water prevention and control empirical formula,calculation formula of the coal mining under ＂ three surface objects＂ and other method were applied to calculate the height of the water flowing crack zone. Meanwhile,the FLAC3 Dsoftware was applied to simulate the overburden rock water flowing crack zone development process of the seam roof overburden failure and to analyze the water flowing crack zone development height under the different pushing forward distances. The plastic zone distribution method was applied to obtain the water flowing crack zone development height in ＂ sudden＂ and ＂ stable＂ states and the pushing forward distance of the coal mining face. With the calculations,three methods showed the heights of the water flowing crack zones would be 93.12,26.67 and 88.00 m individually and the site drilling exploration showed that the height of the water flowing crack zone was 83.78 m. The site,measured data showed that the falling and mining height ratio was 5and the fractured zone height and mining height ratio was 11 under the condition of the fully- mechanize top coal caving mining in ultra thick seam with the soft and weak overburden rock strata in the east part of Inner Mongolia Area.