Prediction of water source and water volume of underground reservoir in coal mine under multiple aquifers

Abstract

The role of coal mine underground reservoir(CMUR) in ‘guide storage and use’ greatly solves the problem of mine water waste. Replenishment and prediction of reservoir water sources provides an important support for the successful development of key technologies concerning CMUR. To study water replenishment for CMUR, the hydrogeological conditions of the Shendong mining area are investigated as an example. Based on the relationship between the development height of the ‘two belts’ of shallow coal seams and the relative occurrence location of aquifers, the aquifers are generalized and classified according to occurrence location. Taking Bulianta Coal Mine as the research background, a discrete element fluid-solid coupling numerical simulation model is constructed to analyze the development characteristics of mining-induced fractures after coal seam mining, and the water replenishment channel of the CMUR is determined. On this basis, analysis is made on the change law of water pressure in the aquifer, aquifuge and coal seam roof under mining action. Taking hydraulic head pressure and water velocity as the judgment basis, prediction and evaluation are made on the water replenishment capacity of CMUR. The research results can provide references for coal mine safety production and mine water protection and utilization.

Analytical method of reservoir capacity of underground reservoir in coal mine: a case study

“…The water storage capacity of an underground abandoned coal mine depends critically on the damage characteristics of the roof strata after coal mining (Wang et al 2018;Chi et al 2022). Along the horizontal direction, on the basis of the displacement angle and the boundary angle, as shown in Figure 2, the roof strata movement and fracture can be described using three zones, i.e., in-situ stress zone, coal pillar supporting zone and re-compaction zone (Palchik 2003).…”

“…The water storage area of an underground reservoir has the function of filtration and precipitation, and the purification of mine water could also be realized to a certain degree (Wang et al 2018). Some water can be directly used in underground mining (Figure 1), and most mine water can be used as the source of industrial, agricultural and domestic water after further treatment (Zhang et al 2021;Chi et al 2022). Currently, 35 coal mine underground water reservoirs have been established in the Shendong mining district and 95% of the water used for industrial, domestic, and ecological uses in the mining area is provided in this way, which greatly reduces the cost of purchasing and transporting water (Gu 2015;Song et al 2020).…”

“…Based on the investigation of the hydrogeological conditions and operation management of the Dagu River underground reservoir, a new assessment system for the operation effects of the underground reservoir was established by . Taking Bulianta coal mine as the research background, a discrete element fluid-solid coupling numerical simulation model was constructed to analyze the development characteristics of mining-induced fractures after coal seam mining, and the water replenishment channel of the coal mine underground reservoirs was determined by Chi et al (2022). How to accurately assess the storage capacity of an abandoned coal mine is considered an urgent problem to settle for extending the technology Zhang et al 2021).…”

Development process and height of the mining-induced water fractured zone over the longwall goaf

“…Engineering practice indicates that underground mining causes the deformation, separation, and fracture of overburdened strata (Liu et al 2018;Wang et al 2019;Wu et al 2019;Fan et al 2022a). Fractures interconnect with each other, forming a water-flowing fractured zone (WFFZ) in which water can flow (Figure 1) (Palchik 2010;Huang et al 2018;Chi et al 2022). Water-inrush accidents and ecological environment damage will occur in the mine when the WFFZ reaches the phreatic aquifer and serious water loss, as shown in Figure 1.…”