由于水资源短缺，陕北矿区利用采空区储存矿井水进行再利用，采空区储水量与采动裂隙空间分布密切相关，为准确预测采空区储水量，基于工作面上覆岩层断裂分带划分结果，确定煤矿地下水库的主要储水空间为垮落带与断裂带的裂隙空间，建立了采动覆岩裂隙率空间分布的计算方法，采用相似模拟试验得出了柠条塔矿1-2煤和2-2煤重复采动后上覆岩层的下沉曲线，计算出重复采动覆岩裂隙率在垂直和水平方向的空间分布情况。结果表明：沿垂直方向，随着高度增加，覆岩裂隙率逐渐减小，1-2煤开采后岩层裂隙率由1.87％逐渐下降为1.18％，2-2煤开采后，裂隙率由12.85％下降为4.11％；沿水平方向，垮落带、断裂带和弯曲下沉带的裂隙率在采空区边缘附近都会产生2个峰值，并且峰值位置逐渐向采空区中央移动，1-2煤开采后，中间压实区的最大裂隙率为1.21％，两边离层区的最大裂隙率为2.19％，2-2煤开采后，压实区和离层区最大裂隙率分别为16.1％和6.54％；重复开采后，上覆岩层的裂隙率显著增加，有利于地下水库储存更多的矿井水，煤层重复开采后，离层区裂隙率最大值由2.19％上升到16.1％，中间压实区最大裂隙率由1.21％上升到6.54％，分别增长了约6.4倍和4.4倍，重复采动覆岩的裂隙率显著增加，增加了储水能力，故下部煤层开采后的采空区能储存更多的矿井水。

Due to the shortage of water resources, the mining area in Northern Shaanxi uses the goaf to store mine water for reuse.The water storage in goaf is closely related to the spatial distribution of mining-induced fractures. To accurately predict the goaf water storage, based on the working plane strata fracture zone, it is determined that the main water storage space of underground reservoir in coal mine is the crack space of caving zone and fracture zone, and the calculation method of the spatial distribution of mining-induced fracture rate in overburden is established. In addition,the subsidence curve of overlying rock after repeated mining of 1-2 coal and 2-2 coal in Ningtiaota Mine was obtained through similar simulation experiment, and the spatial distribution of fracture rate of overlying rock in vertical and horizontal directions after repeated mining was obtained.The results show that along the vertical direction, the fracture rate of overburden decreases gradually with the increase of height. After 1-2 coal mining, the fracture rate of strata decreases gradually from 1.87% to 1.18%, and after 2-2 coal mining, the fracture rate decreases from 12.85% to 4.11%; Along the horizontal direction, the fracture rates of caving zone, fracture zone and bending subsidence zone appear two peak values near the edge of goaf, and the peak values gradually move to the center of goaf. After 1-2 coal mining, the maximum fracture rate of the middle compaction zone is 1.21%, and the maximum fracture rate of the separation zone on both sides is 2.19%. After 2-2 coal mining, the maximum fracture rates are 16.1% and 6.54%, respectively, in the compacted zone and stratified zone; After repeated mining, the fracture rate of overlying strata increases significantly, which is conducive to the storage of more mine water in underground reservoir. The maximum fracture rate of separation zone increases from 2.19% to 16.1%, and the maximum fracture rate of middle compaction zone increases from 1.21% to 6.54%, which increases by 6.4 times and 4.4 times respectively. The fracture rate of overlying strata increases significantly, which increases the water storage capacity, so more mine water could be stored in the mined-out area of the lower coal seam after mining.

0 引言

1 工程概况

2 采动覆岩裂隙场演化相似模拟

   2.1 相似模型及监测方案设计

   2.2 重复采动覆岩裂隙场模拟结果分析

3 结论