Research On The Risk Of Bursting Water From Apical Bed Of A Coal Mine In Ningdong

With the complicated degree of mining conditions deepening,the water damage problem of mine becomes prominent increasingly.Bursting water from apical bed not only made it difficult to mine safely,but also caused great threat to miner's life.Based on theory analysis,combining results of experiment research of water and rock or soil,and using numerical simulation technology,a new coal mine at east of Ningxia as a research object,was studied to predict the inrush risk division in this paper.It is not only important to rich the method of danger division prediction of inrush water from coal seam roof,but it also has an important practical significance to the similar roof to prevent and control the forecasting of water disasters."Three figure-double prediction" method was applied in this article to study the actual situation of the coal field.The main research contents and research results in this paper were listed as follows:(1)Based on the analysis of regional hydrogeology conditions,the water formation was divided into five aquifers,and the way of recharge and run off and excretion of groundwater was made clear.At the same time,the water filling conditions and the main determined controlling factors of the 2 coal roof inrush water were analyzed in this paper.Six thematic maps,including thickness of the aquifer,core to the rock rate,rock brittle plastic ratio,rinses consumption,the unit water inflow,permeability were established.The quantitative evaluation of each aquifer water content has been carried on to draw the water zoning maps of the rich water area of coal seam roof.(2)To study the crack security partition of the coal layer.According to the experience formula,the height of water flowing fractured zone of the main working bed 2 coal was calculated,and according to the three-dimensional numerical simulation of FLAC30,the crack zone height was also given,to consider the actual thickness of coal seam,the results of the height of crack zone was fixed,and which was as the key to determine at the crack of danger and safety indicators.And the minable seam crack safety partition prediction graph was compiled.(3)To compile the comprehensive regional forecast figure of water inrush risk of the size when the main minable seam mining.Overlay hydrogeology partition figure and the security partition prediction figure of minable seam at crack,a comprehensive partition map was accomplished.(4)By contrast analysis,"big well" method and the three dimensional numerical simulation method were used respectively to predict the amount of water-inrush.And at last according to the hydro-geological conceptual model of water,the groundwater numerical simulation software of Visual Modflow was used to predict the amount of water-inrush before and after processing the crack of mine water inflow partitions.(5)Combined with geological conditions of the production mine and the result of the comprehensive regional prediction of roof water-inrush condition,the prevention and control measures of water disasters of mine roof were put forward targeted.