Studies On Enrichment Rule Karst Groundwater And Risk Assessment Of Floor Water Irruption Based On Fractal Feature And AHP In Chaochuan Mine

The Ⅱ1coal is mainly extracted in Chaochuan Mine.The Carboniferous thinlimestone and Cambrain limestone are distributed in coal seam floor.The developledkrast fissures and rich krast high pressure water lead to frequent water burst accidents inthe process of coalmining.At present,the coalmining has been extrended from-10and-250level to-390level,as depth increased,so are the dangers by water filling. It isnecessary to reproduce the distribution law of karst areas and rich water region toensure the security of mining,and it can provide practical significance for the safety ofmine production.This paper discusses the north karst and Chaochuan coal mine development atdifferent depths of the controlled factors based on a comprehensive analysis ofgeological and hydrogeological conditions in Chaochuan coal field,and analysis thekarst development and the distribution law of rich water regions combined with coalmining exposure and mining transient electromagnetic.The analysising show that themain factor of controlling karst development and distribution of the areas of rich wateris structure,which control the division of the mine hydrogeological unit.Factors impactkarst development are lithologic factor,structural factor and water hydrodynamic factor,as depth increased, groundwater runoff conditions weakened,coupled with dissolutionreaction in the contact surface which lead the erosion of groundwater to decline,so thedeep karst development is mainly affected by facture of structural.Expose material of mining and transient electromagnetic prosprcing data indicatethat karst development is strong at level of-10,and which is medium at the level of-150~-250and weaker below the level of-250m. Karst development of Niuzhuang coalmine is weaker than Chaochuan coal mine which shows that karst development andconnectivity become weak and non-uniformity is gradually increased as depthincreased,and there are karst relative growth area and water-rich area under the controlof small faults,and the law of karst development in the east region is weaker than thewest region is still exist.The main structure of Chaochuan coal mine is fracture,and there are two groups offracture with strikes of NW-NWW and NEE-E,the large fracture exist in the coal mine divide it into three separate hydrogeological units.Structural development is strong inthe northwest and central of Chaochuan1stmine,and horst-graben structure is themainly type of protfolio which undermined the integrity of the rock.This paper using theory of fractal dimension to analysis the comprehensivequantitative evaluation of Chaochuan1stcoal mine,and analysis the relationshipbetween distribution of water bursting points and tectonic network fractal dimension ofthe coupling combined with all of previous mine water inrush accidents, the majority ofwater inrush accidents located in the area that the capactity dimension value is greaterthan0.8,which indicate that as the capactity dimension value increased,the structurebecome more complex,and karst development become stronger and the integrity of coalseam floor become poorer and lead to water inrush accidents.This paper establish the analysis model of influence factors with theory of analytichierarchy process,and determine the judgment matrix of the layers of indicatorscombined with expert scoring method and determine the weight of indicators of everylavel,and then draw the forecast map of water inrush risk level of Chaochuan1stcoalmine，which shows that the high degree of risk of water inrush region accounted for43.6%of overall scope of the mine.It has happened18water outbursts in Chaochuan1stcoal mine,and17of them distributed in the more dangerous and hazardous areas,so thegoodness of fit to actual condition is up to94.4%,so as to provide scientific basis formaking plans to prevent and cure water in the future.