特厚松散含水层下缩小防水煤柱开采实践

Mining Practice of Narrowing Waterproof Coal Pillar Under Extremely Thick Unconsolidated Aquifer

以谢桥煤矿煤系地层内新生界冲积层结构及其含、隔水性特征等为背景,运用理论分析和相似模拟方法研究采动岩体运移破坏规律及"两带"发育特征,并建立工作面防水煤岩柱地层结构模型。同时,运用数值模拟方法模拟邻近煤层开采影响下1202(1)工作面回采上限不同时覆岩渗流场的分布情况。研究表明,防水煤柱缩小后,1202(1)工作面覆岩塑性区将波及到上部含水层,但密度较稀少,在保护层和采空区覆岩压实作用下,渗流轨迹发育也并不连续,含水层水体流至工作面的水量有限,缩小防水煤柱安全可行,共解放呆滞煤量3.5万t。

By applying theory analysis and similar simulation method,the mining rock movement and failure laws and development characteristics of ＂ two zones＂ are researched,and the stratigraphic structural model of waterproof pillar is built based on the structure of Cenozoic alluvium and it＇s permeability in Xieqiao Coal Mine. Meanwhile,the seepage field of overlying strata under the influence of adjacent coal seams mining is acquired by using numerical simulation method when the mining upper limit of 1202（1） face is different. The research shows that the plastic zone will further develop and spread to upper aquifer after narrowing the waterproof coal pillar,but its density is relatively rare. The development of seepage path is not continuous under the action of protective layer and goaf strata compaction. Therefore,the water of aquifer infiltrating to the face is limited,and it is safe and feasible to narrow the waterproof coal pillar and the liberated coal is 35 000 t.