Study On Evolution Of Mine Water Flow Field And Water Hazards Prevention Affected By Abandoned Mines

The number of closed pit mines in China has increased dramatically due to the depletion of coal resources and other factors.The drainage activity stop after the mine is closeds and the groundwater level in the mining area quickly rises with the accumulation of time.It will not only cause changes in the groundwater flow field and chemical field of the abandoned mine,but may also cause changes to the adjacent mine.Meanwhile,it has led to a series of geological disasters.Therefore,the research of mine water flow field is of great significance to the management of water resources and water disaster prevention in mining areas.In this paper,took the impact of the closed pit of Yanma mine in Jiaozuo on adjacent mines as a subject and the Jiulishan mine is used as the research object.Collected and collated hydrogeological resources of the research area,and analyzed the groundwater dynamics.Based on the characteristics,groundwater flow simulation was performed,and analyzed the impact of the closed pit of Yanma mine on the groundwater level and water flow field of Jiulishan mine,and evaluated the water damage of the working face that was more affected by Jiulishan mine.The main research results are as follows:(1)Based on the geological data of Yanma mine,the water volume of 27 mining areas adjacent to Jiulishan mine was calculated by using the mining space method.A ccording to the water filling speed and water volume of Yanma mine,the relationship between water filling space and water height relationship,a preliminary analysis was made on the process of water level rise in Yanma mine.(2)On the basic of collecting the research area data,and based on the statistical analysis of the characteristics of the water level and the amount of water in the study area.Affected by the closed pit,the water level of the aquifer adjacent to Yanma mine has a certain upward trend.The water level of the L8 limestone aquifer fluctuates greatly and is easily affected by other factors;It was also found that after the pit was closed,the amount of gushing water in the mine increased significantly,and its changing trend changed from the original ups and downs with the rainfall to a rising upsurge;Based on the results of water quality analysis,it was determined that the water chemical type of Taihui water is still mainly HCO₃-Ca·Mg,and Ca²⁺,Mg²⁺,and HCO₃^-in the groundwater of Jiulishan mine increased after the pit was closed.(3)Correlation analysis was performed on the influencing factors of mine water inflow using SPSS software,and the analytic hierarchy process was used to quantitatively determine the weight of each influencing factor of groundwater dynamics in Jiulishan mine.(4)Based on the analysis of the aquifer in the mining area,groundwater flow model is established by Visual Modflow software.The model is identified and verified based on the long-term water level observation data in the mining area,and the good water level change curve is fitted to analyze the water level and flow field changes Trend,it was found that the groundwater level near the closed pit mine has a certain upward trend,and the water level line becomes dense,and the precipitation funnel in the west of the mine has a tendency to become smaller.(5)According to the height of water accumulation in the 27 mining area of Yanma mine,firstly evaluate the safety of waterproof coal pillar between the two mines,and then evaluate the water inrush situation,fault situation and safety of the roof and floor of the 14142 working face of Jiulishan mine,which is greatly affected by the closed pit.