选取神东矿区拟建地下水库22614工作面为研究背景,利用工作面开采相似实验和矿井水浸砂岩加载实验,模拟采场覆岩运动规律和应力分布状态,分析采空区覆岩结构特征,建立考虑矿井水流速和时间效应影响的煤矿地下水库储水系数计算模型。研究结果表明:模型工作面开采基本顶初次垮落步距46cm,基本顶周期垮落步距7~16cm;采空区覆岩仅存在裂隙带和垮落带,垮落带岩块间存在大量非完全接触的空洞、空隙及欠压实裂缝,是煤矿地下水库最主要的储水空间;采空区岩体承载应力沿走向基本呈“∩”形分布,最大应力趋于1.5MPa,覆岩位移以走向中心线为对称轴呈“∪”形变化,最大位移为-2.5cm。基于采空区覆岩关键层运移轨迹构建其底面下沉曲线函数方程,数学量化采空区垮落带体积、垮落带岩体空隙量和吸水量,建立包含岩石碎胀系数等参数构成的煤矿地下水库储水系数计算模型,通过明确砂岩碎胀系数与矿井水流速和时间的数学关系,进一步完善煤矿地下水库储水系数计算模型,并对模型进行实例计算和实验验证,模型计算储水系数0.1965,实验测定储水系数0.2104,证明了计算模型的准确性,可为煤矿地下分布式水库库容设计和储水调度提供重要理论依据。

Coal mine underground reservoir proposed 22614 working face is selected as the research back- ground, upon which similar experiment of working face mining and loading experiment of mine water soa-king sandstone are conducted, and motion law of overlying strata and stress distribution status are simula- ted. Further, overlying strata structure of goaf is analyzed, and storage coefficient calculation model of coal mine underground reservoir is set up concerning the effects of coal mine water velocity and time. The results show that the old roof first caving step in the model working face is 46 cm and periodic caving step is 7-16 cm. There are only fracture zone and caving zone in the overlying strata of goaf, and there are a large number of incompletely contact cavities, voids and cracks undercompacted between rock blocks in caved zone, which are the main water storage space of underground reservoir of coal mine. The rock bear- ing stress in goaf has a “∩” shape distribution along goaf strike, and the maximum stress reaches 1.5 MPa. The overlying strata displacement of goaf shows a “∪” shape change with the symmetry axis of goaf strike center line, and the maximum displacement is -2.5 cm. Based on the key strata motion trail, its bottom surface subsidence curve function equation is built, and caving zone volume, void volume and water quantity of rock in caving zone are quantified mathematically. Storage coefficient calculation model of coal mine underground reservoir is established with some parameters such as rock hulking coefficient. By clarifying the mathematical relationship between sandstone hulking coefficient and coal mine water ve- locity and time, the storage coefficient calculation model of coal mine underground reservoir is further im- proved, and calculated by examples and verified by experiments. Storage coefficient calculated by the model is 0.196 5, while storage coefficient measured by experiment is 0.210 4, which proves the accuracy of the calculation model. It could provide an important theoretical basis for storage capacity design and wa- ter storage scheduling of coal mine underground distributed reservoir.