Research On Prediction Of Coal Seam Floor Water Inrush

As a traditional province rich of energy in China, the coal industry has been the pillar industry which support the economic development in Shared. In recent years, the demand for energy constantly increasing with the rapid development of social economy, and output production of coal in Shanxi kept breaching new records. However, along with the continuous mining of coal resources, coal mining water inrush accidents have become increasingly outstanding, which is not only a serious threat to the life safety of the staff, but also restricts the rapid development of coal industry. Therefore, to prevent the accidents of coal mining water inrush has become the common concern of governments and the coal enterprise, as well as the important research topic at present.Taking a coal mine in Shentou Spring as research object, this paper analyzed the possibility of water bursting in two major mining coal seams (No.4 and No.9) floor base on the relevant data, as well as predicted the water bursting discharge in risk area of No.9 coal seam, which could provide technical support and scientific basis for the safety production of coal mine and protection of karst water environment in Shentou spring area. The major results are as follows:(1) According to the data of pressure and thickness of the aquiclude, using water inrush coefficient method, the possibility of water-inrush from the floor of the coal seam No.4 and No.9 was evaluated, and the results showed that almost the whole area of coal seam No.4 is in a security zone, while the most area of the coal seams No.9 is in a risk zone.(2) Further, based on the results of water inrush coefficient method and using the vulnerable index method which takes associated factors into consideration, the possibility of water bursting from the floor of the coal seam No.9 was evaluated, and the results are tested based on the borehole data. The results show that the vulnerable index method is feasible to evaluate the possibility of water bursting from the floor of the coal seam No.9 and the accuracy is high. According to the evaluation results, relatively safe area and safe area accounted for 31.02%, medium vulnerability region accounted for 26.46% of the coal seam No.9, and the vulnerable zone and fragile area accounted for 42.52%.(3) By contrast with the process and the results of water inrush coefficient method and vulnerability index method, it can be seen that although the water inrush coefficient method needs less data and simple calculation, the evaluation result is too cursory. While the vulnerability index method considers the factors effecting on the floor of coal seam comprehensively, although the calculation is more complicated, and the results is more reasonable.(4) Based on the evaluate results of for the coal seam No.9 by water inrush coefficient method, the maximum amount of water inrush in two risk sites which were predicted by BP neural network model were ranged between 474.8 and 509.94 m3·n-1. The predicted results show that the water inrush accident of the two sites may reach the low level.(5) Based on the results of water inrush risk evaluation and prediction of the amount of water inrush, combined with the actual situation of the coal mine, measures were proposed for prevention and control of mine water inrush, such as strengthening the exploration work, setting up long-term observation wells, leaving reasonable waterproof coal pillar, equipping with safety-monitoring system, and other assocaiated with measures for prevention and control of coal mine water inrush.