Abstract Characterizing the mining induced temporal changes of hydraulic properties of the overburden aquifer is significant for groundwater resource protection. Conventional hydrogeological methods (e.g. hydraulic test, physical model test and numerical simulation) of determining hydraulic properties of the overburden aquifer cannot quantitatively analyze the temporal changes of the hydraulic properties induced by mining disturbances. This paper demonstrates a quantitative determination for the temporal changes of parameters (compressibility, porosity and specific storage) in the overburden aquifer influenced by the mining processes, based on in-situ continuous measurements of groundwater level that was affected by earth tide, atmospheric loading and mining disturbances. The results showed that, when working face reached a certain distance (127 m from borehole J6 in this study), those parameters (compressibility, porosity and specific storage) of overburden aquifer began to show gradual decrease, with approximately up to two order of magnitudes. After the working face passed by the observation borehole J6, those properties of overburden aquifer recovered in about 80 days, which might reflect the characteristic of elastic deformation of the aquifer. Those findings of the mining induced parameters’ temporal changes could improve our understanding of the mining effects on aquifer system and could be meaningful in groundwater resource protection.

中文翻译：

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西北宁条塔煤田长壁开采引起上覆含水层水力性质的时间变化

摘要 表征开采引起的上覆含水层水力特性的时间变化对地下水资源保护具有重要意义。确定上覆含水层水力特性的常规水文地质方法（如水力试验、物理模型试验和数值模拟）无法定量分析采矿扰动引起的水力特性的时间变化。本文基于对受地球潮汐、大气载荷和大气载荷影响的地下水位的原位连续测量，演示了对受采矿过程影响的上覆含水层中参数（压缩性、孔隙度和比存储量）的时间变化的定量确定。采矿干扰。结果表明，当工作面到达一定距离（本研究距钻孔J6 127 m）时，上覆含水层的这些参数（压缩性、孔隙度和比储量）开始呈现逐渐下降的趋势，大约下降了两个数量级。工作面通过观测井J6后，上覆含水层的性质在80 d左右恢复，这可能反映了含水层的弹性变形特征。这些采矿诱导参数随时间变化的发现可以提高我们对采矿对含水层系统影响的理解，对地下水资源保护具有重要意义。大约高达两个数量级。工作面通过观测钻孔J6后，上覆含水层的性质在80 d左右恢复，这可能反映了含水层的弹性变形特征。这些采矿诱导参数随时间变化的发现可以提高我们对采矿对含水层系统影响的理解，对地下水资源保护具有重要意义。大约高达两个数量级。工作面通过观测钻孔J6后，上覆含水层的性质在80 d左右恢复，这可能反映了含水层的弹性变形特征。这些采矿诱导参数随时间变化的发现可以提高我们对采矿对含水层系统影响的理解，对地下水资源保护具有重要意义。