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

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.

Study on Failure Characteristic Simulation of Seam Floor for Coal Mining above Confined Aquifer Based on Fluid-Solid Coupling Theory

Water inrush is one of the main types of coal mine water disaster. Based on fluid-solid coupling theory, the confined water inrush numerical model is performed using FLAC3D program and similar simulation experiment, and the floor damage field and confined water vector field are simulated. The results show that, in the coupling action of mining stress and pressure of confined water, the mining floor was divided into four zones, namely the mining damage zone, effective confining protection zone, confined water soil-fluid coupling lifting zone, original confined water lifting zone. Confined water-conductive zone with the periodic roof pressure fluctuate, at each pressure and flowing zone height reaches the maximum, rise with height remained unchanged, the distribution shape of a "wave", water inrush is the results of effective connectivity of mining damage zone and Confined water-conductive zone, plate thickness of water-resisting layer exists or not, waterproof performance and the pressure of confined water inrush size is the key

Development of Mine Water Source Identification System Based on MapObjects

In order to realize the mine water source identification and to prevent water accidents, taking Xinglong Zhuang coal mine’s lower group coal mining as an example, based on the analysis of mine hydrogeological conditions, the mine water source identification system was designed by using the software of MapObjects powerful spatial analysis ability and Bayesian classification analytical method. The software can achieve mine water source identification and provide a certain basis for mine water disaster prevention and control.

Major Characteristics of China’s Coal Mine Water Disaster Occurred in Recent Years

In China, water disaster often occurred in coal mines in recent years. According to official statistics on coal mine water accidents occurred in recent twelve years in China, major characteristics of the water disaster have been illustrated. The result shows that the number of both water accidents and corresponding fatalities decreased from 2001 to 2012. And apparently, the accidents occurred in township-owned coal mines and triggered by gob area water accounted for a higher proportion, respectively.

Types and Primary Characteristics of Coal Mine Water Disaster

Based on present condition analysis of coal mine water disaster occurred in recent ten years, classification bases such as water source, water passage, water disaster form, economic loss and casualties caused, aging characteristics and spatial distribution relationship between coal seam and water source of the disaster are proposed. According to water sources, the disaster can be subdivided into natural and artificial source coal mine water one. According to water passage, coal mine water disaster can be subdivided into natural and artificial passage one. According to the spatial distribution relationship, it can be subdivided into roof, periphery and floor water inrush disaster. According to damage form, the disaster can be subdivided into normal temperature, abnormal temperature and corrosive one. Based on economic loss and casualties, the disaster can be subdivided into general, larger, great and special great coal mine water disaster. And according to aging characteristics, it can be subdivided into instant, hysteretic, gradual and skipping coal mine water disaster. Finally, typical characteristics of each disaster are analyzed preliminarily.