松散承压含水层特征对其载荷传递特性的影响研究

Study on the influence of the characteristic of unconsolidated confined aquifer on its property of load transfer

以松散承压含水层下采煤压架突水灾害防治问题为工程背景，基于含水层载荷传递机理设计了专门的模拟实验装置，就松散承压含水层赋存特征对其载荷传递特性及关键层复合破断的影响进行了研究。结果表明：松散承压含水层骨架颗粒粒径越大，组分越单一，含水层的流动补给性能越好，作用在基岩顶部的载荷较大，覆岩越易发生复合破断，易导致压架突水事故；骨架颗粒粒径越小，粒度组分复杂，含水层流动补给性能越差，作用在基岩顶界面的载荷易随采动降低，含水层载荷传递系数小，覆岩关键层自下而上逐层破断，不易导致压架突水事故。研究形成了含水层载荷传递系数的确定方法，在祁东煤矿的开采条件下，洪冲积扇区域含水层的载荷传递系数应为0.83~0.94，漫滩沉积区域可取0.69~0.71。

In response to the issue of prevention of support crushing and water inrush disaster during mining under unconsolidated confined aquifer, a specialized simulation experiment set based on the mechanism of aquifer load transfer has been designed and the influence of occurrence characteristic of unconsolidated confined aquifer on its property of load transfer and key stratum compound breakage has been studied. The result indicates that load transfer effect on the unconsolidated confined aquifer is closely related to its framework grain characteristic. The larger the skeleton granule diameter is, the simpler the component is, and the better the property of flowing and replenishment is. Therefore it can transfer load to top overburden continuously and uniformly and make the load on top of overburden larger, which easily causes overburden integral breakage and results in support crushing and water in-rush disaster. While the smaller the framework grain diameter is, the more complex the component is, and the poorer the property of flowing and replenishment is. Load applying on top of overburden can reduce during mining and aquifer load transfer coefficient can become smaller. Therefore, key stratum breaks layer by layer and hardly causes support crushing and water inrush. Calculating method of load transfer coefficient of unconsolidated confined aquifer has been confirmed. Load transfer coefficient should be 0.83 to 0.94 in alluvial and pluvial fan area of Qidong coal mine, while non-alluvial and pluvial fan area should be 0.69 to 0.71.