Study On Early Warning Index And Method Of Water Disaster Risk Monitoring In Tingnan Coal Mine

With the increase of resource demand,coal mining intensity and mining depth increase,the occurrence of mine water disasters is more frequent,which greatly endangers the safety of mine production.The key work of coal mine water disaster is prevention,water disaster prediction is the basis of prevention.The research on monitoring and early warning of coal mine water disaster risk is a new method for water inrush prediction.This paper focuses on the problem of coal mine water disaster risk monitoring and early warning indicators and early warning methods,taking Tingnan Mine as an example.Based on the actual investigation of Tingnan Coal Mine and the data of mine risk monitoring indicators,the water disaster risk monitoring and early warning indicators are proposed,and the dynamic early warning model with single factor and multiple factors is established according to the indicator data.Based on the actual geological conditions and production conditions of the mining area,and according to the relevant laws and regulations,the discriminant criteria and grading early warning criteria,namely early warning criteria and early warning threshold,are proposed.Finally,the water condition monitoring and water disaster early warning platform of Tingnan coal industry was constructed by combining single factor early warning model and multi-factor coupling early warning model,which played a good role in advanced prediction and prevention of coal mine water disaster.The main achievements of this paper are as follows :(1)The general situation,geological conditions and hydrogeological conditions of Tingnan Coal Mine are introduced.Combined with the water filling conditions and mining conditions of the mine,the water inrush mechanism of the thick sandstone aquifer in the roof of Tingnan Coal Mine is summarized.That is,the upper strata of the coal seam are out of balance due to coal seam mining,the surrounding rock pressure is redistributed,and the water flowing fracture zone is produced.The aquifer water in the upper part of the coal seam is infiltrated and even gushed along the water flowing fracture,resulting in water inrush in the working face.Summarizes the current situation of mine water disaster since mining and water prevention capacity and measures.(2)According to the selection principle of monitoring indicators and the location requirements of monitoring points,the water disaster risk monitoring index is established.The water disaster risk monitoring index includes dynamic indicators(water temperature,water level,underground sudden(gushing)water volume,drainage capacity,goaf water volume,adjacent goaf water volume,water containing(separated)water layer,three-zone height,water quality,water pressure,precipitation,river water level,roof and floor damage degree),static indicators(stratigraphic structure,structure,hydrogeological basic work,water prevention and control engineering)and related indicators(microseismic monitoring data,geophysical exploration results).(3)The combined weighting method of objective entropy weight method and subjective analytic hierarchy process is used to determine the comprehensive weight of each index in the water disaster risk monitoring index of coal mines.It is concluded that the three indexes with the largest weight are the underground sudden(gushing)water amount,microseismic monitoring data and precipitation.The microseismic monitoring data adopt the location height of microseismic events,which reflects the height of water flowing fractured zone to a certain extent.From the water disaster risk monitoring index,three indexes,namely aquifer water level,height of water flowing fractured zone and water inflow,which are most directly related to roof water inrush of working face,are selected as early warning indexes.(4)Fuzzy comprehensive evaluation model and expert scoring method are used to comprehensively evaluate the risk of water disaster,namely the risk of water inrush.The risk of water disaster in coal mines is divided into four grades,representing low risk,low risk,high risk and high risk,respectively.The prediction and early warning models are established from the aspects of single factor and multiple factors to predict the predicted early warning index values.Then from the qualitative and quantitative aspects,according to the coal mine water inrush signs and water inrush criterion research early warning criteria,determine the early warning threshold of early warning indicators.(5)Finally,taking the 207 working face of Tingnan Mine as an example,the water monitoring and water disaster warning platform is arranged.The platform constructs five systems and a variety of water disaster risk early warning models,including microseismic monitoring and early warning system,and realizes the monitoring and early warning of coal mine water inrush disaster.The results show that the water disaster monitoring and early warning system of Tingnan Coal Mine can monitor the relevant early warning indicators of coal seam roof and floor in mining,the damage of water flowing fractured zone,and the mechanical deformation and failure of roof and floor rock mass.Combined with the early warning methods and early warning criteria of indicators,the monitoring and early warning of coal mine water inrush can be realized.There are 57 figures,28 tables and 74 references in this paper.