谢桥矿水体下煤层1202(1)工作面提高开采上限研究

Study on extending mining upper limit of 1202(1) working face under water body in Xieqiao Coal Mine

为提高谢桥煤矿松散含水层下1202(1)工作面开采上限,分析了井田内新生界冲积层结构及其含、隔水性,确定了工作面属Ⅱ类水体压煤,其主要影响水源为顸板砂岩裂隙水及中部含水层下段;建立工作面防水煤岩柱地层结构模型,运用理论分析和钻孔实测方法对两带发育高度进行预测;运用数值模拟方法模拟邻近煤层开采影响下,开采上限不同时工作面覆岩破坏场及覆岩水体渗流场的分布情况。研究表明,开采上限提高后,裂隙带将进一步发育并间接波及上部含水层,在保护层和工作面中部采空区覆岩压实作用下,含水层水体将主要渗流至工作面下端部,并最终流向底部松散区域。现场实践中,开采上限提高至-390 m安全可行,解放呆滞煤量3.5万t。

To extend mining upper limit of 1202（1） working face under loose aquifer in Xieqiao Coal Mine,it was affirmed that the face was below water bodies which was belong to case-Ⅱ waters,and the main water sources were roof sandstone fissure water and the lower segment of the middle aquifer based on the contrastive analysis of the structure of Cenozoic alluvium and it＇s aquosity and water-resisting property.The workability was determined preliminary by building the stratigraphic structural model of waterproof pillar and applying the theory analysis and drilling measurement method to predict the height of the ＂two zones＂.The distribution of failure field of the overlying strata and seepage field of overlying water-body with the influence of the adjacent coal seams mining were acquired by using numerical simulation method when the mining upper limit of 1202（1） face was different.The research showed that the fissure zone would further develop and spread to upper aquifer indirectly after extending the upper limit of1202（1） face,and under the influence of the protective layer and the goaf strata compaction of the central face,the water of the aquifer would mainly transfer to the bottom of the face,and then seep to the loose area at the bottom eventually.In the field practice,it was safe and feasible to extend the mining upper limit to-390 m level and the liberated stagnant coal was 35000 t.