Sensitivity Analysis On Controlling Factors Of Water Inrush

Mine water disaster is one of the biggest obstacles affecting and restricting China's coal production. Only the floor karstic water threats about 42 percent China's coal base. Therefore, the research on water invasion regularity of coal floor has an important practical and theoretical significance for the coal mine safety production.In this paper, FLAC3D finite difference software is used to simulate the depth of destroyed floor in different working face length, mining depth, exploiting thickness, water pressure and floor lithology. Then, simulation results are calculated by variance analysis method. On the basis of that the sensitivity of main controlling factors is determined. Firstly, according to the actual production experience and results of previous studies, main influence factors of floor water invasion and action principles of these factors are discussed. Then, combining geological conditions of this study, the controlling factors are determined. On the basis of "down three zone" theory, using rock fracture mechanics theory, the formation mechanism and calculation formula of the down three zone are analysis, and dynamic mechanism of floor water invasion is revealed. All of that provides a theoretical basis for sensitivity analysis of floor controlling factors. Then, according to the actual conditions, simulation geological condition is set. Meanwhile, combination experimental conditions, level values of controlling factors are determined. In order to reduce workload, author identified test plan using orthogonal test, and did the numerical simulation by FLAC3D. Through the work of before, the depth of destroyed floor under different controlling factors are determined. Eventually, using orthogonal analysis, charts and linear regression method, further discussed floor water invasion regularity and the sensitivity of main controlling factors. It's useful for preventing water invasion. And it provides a theoretical guidance for coal mine safety production.Water-inrush is the result of many factors working together. So water-inrush mechanism is very complicated. This paper presents a simple water-inrush law under the ideal geological conditions. In the actual production, coal mines should be based on the specific circumstances of water-inrush simulation to determine water control measures.