Study On The Model Test Of Groundwater Recovery And Seepage Law In Abandoned Mine

With the increasing number of abandoned mines in China,a series of problems caused by abandoned mines have been paid more and more attention.An important feature of abandoned mines is the rise of groundwater.Due to the complexity of hydrogeological conditions of abandoned mines,the hydrogeological work and environmental protection of mines in China are facing new problems and challenges.Therefore,to solve a series of problems caused by abandoned mines,it is necessary to further study the seepage law of groundwater in abandoned mines.In this paper,based on the synthesis of existing domestic and international research results and theories,the law of groundwater seepage in the process of water level rebound is studied with the indoor model test of abandoned mine as the core.First,three conditions essential for the formation of water accumulation in abandoned mines were systematically analysed:water source,water channel and water storage space,and the prediction methods for water accumulation were compared and summarized;the mechanism for the formation of string layer pollution in the Zibo mining area was analysed in depth in terms of pollution sources,pollution pathways and water quality changes,and it was concluded that the most direct cause of string layer pollution was various types of water supply wells with bad water stops.Secondly,using the stratigraphic structure of the Zibo mine area as a reference,the strata after generalization were scaled down,and an indoor test platform for abandoned mines in typical North China coalfields was established;the corresponding simulation materials were selected for each stratum by controlling the permeability coefficient,and the process of water rebound and stratigraphic pollution in abandoned mines was reduced.The experimental process was jointly interpreted by camera,pore water pressure monitoring and resistivity monitoring,and the correspondence between the range of water rebound and the resistivity profile was explored;a nonlinear fit was made to the pore water pressure curve using the classical "S" model,and the variation laws of resistivity and pore water pressure were obtained.Finally,the FEFLOW simulation software was used to numerically simulate the process of standing water back up and to compare and complement the results obtained with the indoor tests.The research in this paper has some theoretical and practical significance for further understanding the movement laws of groundwater,the changing laws and influencing factors during the rising process after mine closure.