Capacity characteristics of the underground water reservoir of an open-pit coalmine: a case study in Baorixile

Abstract

Water storage capacity has always been the core component of the underground water reservoir in open-pit coalmines. Taking the western underground water reservoir of Baorixile open-pit coalmine as the research background, boreholes in the waste dump overlying the underground water reservoir were designed and drilled, and the capacity characteristics of the underground water reservoir were studied by a layered summation method. These test results revealed that: (1) the regional strata from shallow to deep are the near-surface loose layer, upper bench loess, mixed stripping material, glutenite water reservoir layer and rubble collecting ditch; and the glutenite water reservoir layer is the main water storage body of the underground water reservoir. (2) Permeability coefficient, porosity, layered and cumulative water storage of the western underground water reservoir in Baorixile open-pit coalmine increase with the elevation increase, and show a quadratic function relationship. (3) The total storage capacity of the underground water reservoir is 1.2234 Mm3, and the average porosity is 0.1003, that is, each volume of the water storage medium can store 0.1003 volume of water. These results provide a scientific basis for the evaluation and determination of the water storage capacity of the underground water reservoir in open-pit coalmines.

Research on the Distribution Characteristics of the Bulking Coefficient in the Strike Direction of the Longwall Goaf Filled with Slurry

“…Wang Yutao [14][15][16][17][18] built a threedimensional spatial dynamic distribution model of voids and permeability in the goaf based on the theory of the conservation of mining space, and obtained the distribution maps of voids and permeability in different spatial positions and different mining end times; Liang Bing [19][20][21][22][23][24], etc., studied the distribution law of stress change and bulking coefficient of caving rock mass in the goaf of Shendong mining area, analyzed the structural characteristics of overburden "two zones", and divided the stress and bulking coefficient of caving rock mass in the goaf. Liu Yiyang [25][26][27][28] and others put forward a chain arch structure inclined to compound force, analyzed the characteristics of the chain arch under the influence of area length effect, and obtained the distribution characteristics of the crack field and void ratio of an "O"-shaped ring. The above research mainly focuses on the spatial distribution of the void space and permeability under the condition of goaf water storage.…”

Research on the Capacity of Underground Reservoirs in Coal Mines to Protect the Groundwater Resources: A Case of Zhangshuanglou Coal Mine in Xuzhou, China

“…Water storage capacity refers to the series of storage spaces, such as voids or fractures, formed after the upper strata of the mining area are destroyed [35][36][37][38], with some authors calculating the storage capacity based on the storage water level at different positions in the overlying fracture zone. Pang et al [39] proposed a theory of storage space for underground water reservoirs in coal mines with different rock formations. Rudakov et al [40] developed an analytical model that allows realistic prediction of transient mine water rebound and inflows into a mine with layered heterogeneity of rocks, irregular form of the drained area, and the inflow/outflow to a neighboring mine and the volume of voids as a distributed parameter without gridding the flow domain performed in numerical models.…”

Spatial Structure Characteristics of Underground Reservoir Water Storage Space in Coal Mines Considering Shape Characteristics of Crushed Rock

“…However, their simulation process overlooked the influence of particle size and shape of the crushed coal and rock samples. Pang et al [18] examined the fracture structure of the overlying rock mass on the working surface by utilizing fracture mechanics theory and UDEC software. They also derived the temporal and spatial evolution patterns of the effective storage coefficient through the vertical displacement trajectory curves of the subdivided overburdens of the underground reservoir.…”