Investigation On The Development Law Of Water Flowing Fractured Zone In Overlying Strata Of Coal Mining In Mountain Area

Due to the coal mining induced overburden rock deformation and failure,it will lead to the formation of water flowing fractured zone,and then the water in the aquifer in the mining area will flow into the mined out area,this can cause mine water damage.Therefore,it is of great significance to study the development law of the fractured water conducting fractured zone in overlying strata,so as to reasonably determine the upper limit of safety mining and the method of coal mining.At present,the study on the development regularity of water conducting fractured zone is mainly concentrated in the Middle East plain,due to the fluctuation of the mountainous area,the coal mine in mountain area will be different from the plain area in the development of the water flowing fractured zone.At present,it is not enough to study the development height of the water flowing fractured zone in the coal mining area in southwest mountain area.Therefore,it is of great significance to study the law of the development of the water bearing fractured zone.In this paper,the 11607 working face of the first mining area of Qinglong Coal Mine in Southwest Guizhou coalfield is studied.According to geological data mining and coal rock mechanical parameters,this paper adopts the method of theoretical analysis,field measurement,physical model test and numerical simulation and curve fitting to study the movement law of overlying strata and the development characteristics of water flowing fractured zone in coal mining area.(1)Based on the data collected from Qinglong Coal Mine,the geological and hydrogeological conditions of the study area are analyzed.(2)The field measurement of 11607 working face is used the method of underground upward hole sublevel water infusion leak detection,then the height of water flowing fractured zone in overlying strata is obtained.(3)Based on the similar physical model test method,the overburden structure and failure law of coal mining in mountain area are simulated.And then based on the principle of similarity simulation experiment,the height of water flowing fractured zone is obtained.Finally,the height of the water flowing fractured zone is verified by the measured data.(4)The discrete element numerical simulation model of coal seam mining in mountainous area is established by FLAC3 D numerical simulation software,and the variation law of stress field,vertical displacement and plastic zone is analyzed.Numerical simulation method is used to obtain the height of water flowing fractured zone.Finally,the height of the water flowing fractured zone is also verified by the measured data.The validity of the work surface model and the physical and mechanical parameters and the applicability of the method are proved by the double verification of the test and simulation.(5)Based on the analysis of the volume of surface quaternary sandy clay,the development law of the water conducting fractured zone of mining overburden rock in coal mine and plain area is studied by using the equal volume method.(6)Such three kinds of influence factors of the development of mountain coal mine water flowing fractured zone as the surface roughness and thickness of coal seam,the dip angle are selected to study the relationship between each single factor and mountain mining water flowing fractured zone development law by single factor analysis method and curve fitting method.Finally,the relationship between the factors and the development of water flowing fractured zone in mountain area is obtained by curve fitting.The research results of this paper lay a foundation for the further study of the development law of the water conducting fractured zone in the overlying strata in the mountain area,which has certain guiding significance for the exploitation of the mining area in the southwest mountain area.