Study On Evolution Law Of Stratifugic Water Inrush Disaster Of Overburden Strata Induced By Mining

The stratifugic water inrush from separate strata is a special case of roof water inrush.The main difference between stratifugic water and roof water inrush is that the former one occurs in the separation space between covered rocks.Based on the analysis of water inrush from the 1121 first mining face of Hongliu Coal mine,this paper takes its 1121 working face as the background,and does some research on the stratifugic water inrush from the analysis of overburden rock structure and hydrological structure above the actual working face.In recent years,stratifugic water inrush events have occurred in many places in China and happened under different geological backgrounds.Water inrush from stratum separation has the characteristics of its unconspicuous symptom and large instantaneous water inrush,and it is difficult to get the complex reason of it,so the scientific content that can be studied is rich and has its practical significance.This paper selects Yuanyang Lake mining area coal mine region as the stratifugic water irruption case background,its geological characteristics can be summarized as composed of sandstone and mudstone cycle nearly horizontal sedimentary strata,thick coal seam,loose red soil layer,no igneous rock,no complex structures,hydrogeological structure is composed of multiple aquifers and water-resisting layers.In this paper,the geological model of stratifugic water inrush and its formation process are studied.A physical model and a numerical model based on the geological archetype were established to explore the causes and laws of water inrush hazard.Factors of water source,seepage channel and mining action are selected as the hazard sources of stratifugic water to probe into the dynamic changes,which causes by the excavating of the coal mine.The main objects of model research are water flowing fractured zone,bed separation and stratifugic water.By combining the dynamic change laws of hazard sources with the actual water inrush,the fuzzy evaluation model of isolated water inrush is established,and conversely,the dynamic fuzzy evaluation of stratifugic water inrush risk with the advance of mining distance can be well realized.In this paper,the theoretical method is applied to determine the inevitability of the formation of the special overburden structure of the roof of the working face.The physical model discussed the feasibility of simulating soft and hard rock layers with similar materials of different formulations.The observation and experimental results summarized the dynamic development rules of water-conducting fracture zone and separation fracture zone.The numerical model discusses the dynamic changes of displacement field,stress field,pore pressure field and seepage field with mining.In FLAC3 D,strain increment and saturation can be used to reflect the situation of zonation and zonation water.Changes in rock permeability due to mining can be defined using the FISH language.The main conclusions of this paper are as follows: the source of water inrush from the separated layer of Hongliu coal mine is the upper stratified gritstone aquifer of Zhiluo formation.The abscission layer is formed between it and the underlying mudstone layer.Overburden stress field,displacement field and flow field all change due to coal seam mining.The fuzzy mathematical model of water inrush from isolated layer,which considers the factors of water source,passage and mining,to makes it have the function of dynamic evaluation.The research conclusion of this paper is consistent with the existing research achievements and the practical project background.On this basis,the dynamic changes of the geological situation were explored,and more details were paid attention to provide some reference for the relevant research on water inrush from stratified water.