Abstract: Underground reservoir is one of the important engineering measures to solve water resource shortage in China. The construction of underground reservoir in mine goaf is of great significance to realize underground space in mine goaf and utilization of mine water resources and energy resources, and promote environmental and ecological protection in mine area. Taking Lingxin Coal mine in Ningxia as an example, a three-dimensional numerical model was established by using finite element method to study mechanical deformation characteristics of artificial dam body of underground reservoir in coal mine under overlying rock mass and design head load. The results show that the deformation of the artificial dam and surrounding rock of the underground reservoir is mainly concentrated in the front section of arch crown support and the bottom floor area of the upstream side, and the deformation of the retaining wall is concentrated in the middle area, and the maximum displacement of the dam is less than 1mm. The maximum stress of the dam is concentrated at the crown of the arch walling support, the maximum stress of the retaining wall is concentrated at the outside of the arch walling support, the maximum stress of the surrounding rock is concentrated at its junction with the arch walling support, and the maximum stress of the dam is less than 3.325 MPa. The maximum equivalent plastic strain of the dam body is located at the junction between arch walling and retaining wall on the upstream side. Numerical calculation and safety factor analysis show that the dam body has good structural stability and meets the purpose of underground reservoir construction and operation.

Key words: coal mine, underground reservoir, strata, designed head load, stability

摘要： 地下水库是解决我国水资源短缺的重要工程措施之一,利用煤矿采空区建设矿井地下水库对实现矿井采空区地下空间及矿井水资源化、能源化利用,促进矿区环境生态保护意义重大。以宁夏灵新煤矿为例,采用有限元方法建立三维数值模型,研究上覆岩体及设计水头荷载作用下煤矿地下水库人工坝体力学变形特性。研究表明:地下水库人工坝体及围岩的变形主要集中于迎水侧的拱形砌碹支架前段底板区域,挡水坝体变形集中在其中部区域,坝体的最大位移小于1mm;坝体的最大应力集中于砌碹支架顶板处,挡水坝体的最大应力集中在其外侧区域,围岩的最大应力集中在其与砌碹支架交界处,坝体的最大应力小于3.325MPa;坝体的最大等效塑性应变分布于迎水侧砌碹支架与挡水坝体交界区域,数值计算及安全系数分析表明,倒锥形坝体的结构稳定性良好,满足地下水库建设和运营的目的。

关键词: 煤矿, 地下水库, 覆岩, 设计水头荷载, 稳定性