Water Abundance Forecast And Water Disaster Danger Evaluation Study Of Sandstone Aquifers

Sandstone aquifers in the roof and floor of coal seams are usually direct water-filling aquifers and have an important effect on coal mines'production. Based on the analysis of the geological and hydrogeological condition, and the past water-inrush data in Jiyang coal mine, the paper forecasted and evaluated the water abundance and the water disaster danger of the sandstone aquifers in the roof and floor of the No1 and No7 coal seams, the main mining coal seams in the mine. The paper dealed with the destruction depth of the coal seams'roof and floor by empirical formula, field detection and numerical simulation and obtained recognition to the development depth of the destruction zones of the main mining coal seams'roof and floor. By analyzing the influencing factors of sandstone aquifers'water abundance, the paper ascertained sandstone aquifers'water abundance's evaluation factors which were sandstone's size and thickness, structure of the coal seams'roof and floor and development condition of the geological structure. Sandstone's thickness variety, its distribution characteristics and the combination characteristics of the sandstone and mudstone was analyzed by drawing depositional section maps. The paper quantativly described the lithology and structure characteristics of the coal seams'roof and floor by constructing lithology structure index and the complexity of structure in the section using similar fractal dimension. Based on the single factor analysis of the lithology and structure characteristics of the coal seams'roof and floor and the geological structure's fractal feature in the section, the paper adopted comprehensive multiple factor analysis to classify sandstone aquifers'water abundance by standardizing the lithology structure index and the structure's fractal value and the sandstone aquifers in the roof and floor of the coal seams in the research area were divided into three levels which were rich water abundance, medium water abundance, weak water abundance. Sandstone's water abundance was detected using transient electromagnetic technology and the result demonstrated that the rich water abundance area was mainly near the structure. Comprehensively considering the lithology structure index, the geophysical exploration results and the results which were obtained by comprehensive multiple factor analysis, the paper carved up the water disaster danger subarea of the sandstone aquifers in the roof and floor of the coal seams and the sandstone aquifers were divided into three levels which were dangerous area, less dangerous area and safe area. The prevention and cure technology ways and measures of the water disaster in the section was probed into.