Fractured zone height of longwall mining and its effects on the overburden aquifers  

作　　者：Guo Wenbing Zou Youfeng Hou Quanlin 

机构地区：[1]Key Laboratory of Comutional Geodynamics, Chinese Academy of Scicence, Beijing 100049. China [2]School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000. China

出　　处：《International Journal of Mining Science and Technology》2012年第5期603-606,共4页矿业科学技术学报（英文版）

基　　金：sponsored by the National Natural Science Foundation of China (No.50974053);Pennsylvania Service Corporation at Waynesburg,USA

摘　　要：As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.

关 键 词：Longwall mining Fractured zone Mining under water body Overburden aquifer 

分 类 号：TD823.41[矿业工程—煤矿开采] X523[矿业工程—矿山开采]