Dissipation Structure And Mechanism Of Mining-induced Mutation Of Aquifuge System

For further development on temporal and spatial evolution mechanism of seepage stability of aquifuge subjected to mining disturbance,dissipation mechanism of overlying aquifuge system and its dynamic response to mining-induced unstabilization were analyzed from the perspective of system theory and catastrophe theory.Theoretical analysis,mechanical calculation and backstepping modeling were synthetically employed to investigate forming mechanism of dissipation structure in aquifuge system,unstabilization mutation characteristics of fractured rock under coupled field,dynamics analysis of mining-induced unstabilization of water-resisting property.Main results were listed as follows.(1)Forming mechanism of dissipation structure of aquifuge system under mining disturbance was revealed.Macro-micro scope of aquifuge system in overlying strata induced by mining was demarcated.A judgement concerning mining-induced aquifuge system had characteristics of dissipation structure was obtained by analyzing external openness,nonequilibrium orderliness,factor nonlinearity and state fluctuation of aquifuge system under the influence of mining disturbance.(2)Unstabilization mutation performance of stress-fracture-seepage coupling field in aquifuge was analyzed.Planar mechanical model of coupled field was constructed based on representation of micro voxel to macro system.Cusp-based catastrophe model regarding horizontal stress and pore pressure as characteristic vectors was established by calculating potential function.Evolution path in three-dimensional space and critical criterion of unstabilization mutation were developed.Evolution characteristics of aquifuge system stability with coal seam excavating were analyzed by backstepping-based modeling and measuring-based comparison.(3)Dynamic response mechanism and threshold effect of mining-induced aquifuge system unstabilization were preliminarily described.Pore pressure entropy was introduced into dissipation structure of aquifuge system.Inducements driving negative entropy flux and positive entropy production were explored,along with entropy reduction effect of aquifuge system in the process of unstabilization.Autonomous dynamic equation regarding super-generalized force and super-generalized flux as independent variable and dependent variable was established.Threshold effect,determined by critical mining scale,of aquifuge system unstabilization was analyzed on the basis of excess entropy production.