A Case Study of the Water Abundance Evaluation of Roof Aquifer Based on the Development Height of Water-Conducting Fracture Zone

Abstract

In the eastern mining area of Ningxia, China, multi-layered sandstone aquifers are widely distributed in the underground. However, the water abundance of these aquifers is not clear, which brings great challenges to the prevention and control of mine water disaster. In this paper, five mining areas in eastern Ningxia were taken as the study area, and the distribution characteristics of aquifer and the mine water filling source were analyzed through the analysis of geological data and numerical simulation. Finally, the lithology influencing index (LII) was constructed, and the water abundance of the aquifer was evaluated. The results show that the sandstone aquifer III in the lower part of the Jurassic Zhiluo formation is the main water-source aquifer of the #2 coal seam in the study area, while the middle aquifer II and the upper aquifer I are indirect water-source aquifers; the areas with extremely strong and strong water abundance are Maiduoshan, Hongliu, the south of Shicaocun, southeast and southwest of Meihuajing, and the central and southern areas of Shuangma mining areas; when the depth of water drainage boreholes in the roof reaches the development height of the water-conducting fracture zone, the pre-drainage measures can effectively control the mining inrush water of the working face and ensure the safety production. This research is of great significance to the prevention and control of mine water disaster.

Allocation and Utilization of Coal Mine Water for Ecological Protection of Lakes in Semi-Arid Area of China

“…With the exploitation of coalfields, much water will be extracted from the underground aquifer. To calculate mine water inflow, virtual large diameter well method [29], rich water coefficient method, numerical simulation [30], and the global optimization-based method [31] are commonly used. In this paper, the water inflow of mine plants in the future is calculated by the mine water coefficient method [32].…”

Water-Filling Characteristics and Water Source of Weakly Rich Water and Weakly Conducting Water Aquifers in the Changxing Formation after Mining Damage

“…This advancement has facilitated the full-height extraction of moderately thick coal seams in a single operation, with some mines achieving a maximum mining height of 3.6 m. Furthermore, due to the significant increase in the scope of the goaf and the completion of the 9 # and 5 # coal seams near the shallow outcrop, a large goaf was formed in the mining area. As a consequence of this extensive mining, a large surface mining fracture failure zone emerged [19][20][21][22]. Research conducted by Wang Beifang et al [23] indicated that the fractures generated by mining have also led to primary dissolution gaps and caves within the Changxing Formation rock mass.…”

Calculation of the Height of the Water-Conducting Fracture Zone Based on the Analysis of Critical Fracturing of Overlying Strata

“…Fan et al studied the development characteristics of the WCFZ through on-site measurement and physical simulation; they revealed the dynamic evolution characteristic of "developmentdevelopment-closure" of the mining-induced fractures and discovered the "mud cap effect" revealed by mining failure under thick mud caprock [6]. Wang et al proposed a new method and its applicable conditions for the division of the "vertical three zones" of mining overburden based on the key stratum stability and the characteristics of post-fracture movement through physical simulation experiments and the key stratum theory [19,20]. These studies provide good ideas for dividing the WCFZ in the mining overburden under general geological conditions and traditional mining conditions.…”