The Study On Distribution And Characteristics Of Water Quality Of Geological Anomaly Body (Karstic Collapse Columns) In Gugui Mine Field

Karstic collapse columns as a special kind of geological bodies in coal with powerfulhydraulic conductivity could communicate with each aquifer, especially the ordovicianlimestone with high-pressure at the bottom of coal measures aquifer, causing floodingaccidents. For preventing these accidents, the problem about deeper study of thedistribution and hydrogeological characteristics of collapse column has to be solved in safemine production. So far,12Karstic collapse columns were found at coalfield in Huainan:1in Kongji mine、2in Xieqiao mine、1in Zhangji mine、1and3suspected in Pansan mine、1suspected in Zhuji mine and1suspected and2geological anomaly bodies with bandedstructure in Gugui mine were included. Whether the2geological anomaly bodies withbanded structure in Gugui mine is real karstic collapse column or not has beencontroversial. Based on many relative literature about coalmine karstic collapse column，different kinds of evidence about geologyand hydrogeology were provided to prove thegeological anomaly body to be real collapse column which is located in Gugui mine. Toresearch the impact of geological anomaly body on water quality, the geological anomalybodies area is divided into three zones to analyze characteristics of water quality in coalmeasures aquifer and limestone aquifer. The results of this paper are summarized below:（1） The geological anomaly bodies in Gugui mine have two tectonic belts: northerntectonic zone basing on the F81^F87faults and south-central tectonic zone basing onF92^F110faults. Synclinal and anticlinal axes in two tectonic belts are consistent with thedirection of the main structural line along NWW direction. Four ancient depressions locatebetween two high angle anomaly zones, F95and F108, along NW30o direction.（2） There are499boreholes and59leaking boreholes in Gugui mine field.83.05%ofthe leaking boreholes are distributed in the two tectonic belts and the highest proportion ofleaking boreholes is in south-central tectonic zone.（3） Gugui mine field is similar to Xieqiao mine in direction of palaeogeomorphologydevelopment、groundwater flow、stratigraphy and a combination of stratigraphy. So there isa basis of the geology and hydrogeology to be karst collapse column.（4） Geological anomaly body in Gugui mine is the possibility of karstic collapse anddrilling pumping tests show that: the faults in the northwest end of the south wing ofGeological anomalies body is substantially free of water, hydraulic conductivity and thelimestone-rich aqueous in north side of geological anomalies body is from medium tostrong, the south side weak. （5） The trend of concentration about six ions in the three zones（collapsed area、influenced area、normal area） of coal measures aquifer is: the closer to collapsed area，thesmaller concentration which Ca²⁺、Mg²⁺、K⁺+Na⁺、Cl^-、HCO₃^-decrease moderately,especially Ca²⁺、Mg²⁺and SO₄^2-decrease obviously from350mg/L in collapsed area to15mg/L in normal area. At the same time, changes in water quality of different coal seamsare obvious in the same area.（6） The trend of concentration about six ions in the three zones（collapsed area、influenced area、normal area） of limestone aquifer is: the concentration concentrate innormal area and scatter in collapsed area.