The Hydrogeological Characteristics And The Influence Of Ordovician Limestone On Mining Lower-Group Coal Seam In Yanzhou Coal Field

This paper analyses the hydrogeological characteristics of Ordovician limestone, andstudies the influence of Ordovician limestone on the exploitation of lower-group coal seam inthe Yanzhou mine area. Based on the geophysical exploration data, drilling data and pumpingtest data, the author analyses the lithologic features, the thickness and their variation, and thewater abundance of Ordovician limestone, carries on the hydrogeological subdivision, andprobes into the change and reason of water level of Ordovician limestone. Bases on thevarious floor the author has studied detailly the water inrush mechanism of Ordovicianlimestone. That is floor failure water inrush, fault water inrush, and canny water inrush.Based on the lithology, thickness of aquifuge and changes of the rock betweenOrdovician limestone aquiferous to lower-group coal seam, the watertightness of aquifuge areevaluated. The influencing degrees that Ordovician limestone on the exploitation oflower-group coal seam is analysed using the way of water bursting coefficient, and predictedthe danger zones of water inrush from floor. Synthetically considering the hydrogeologicalcharacteristics of Ordovician limestone, the paper talked about the preventing and treatingwater disaster of Ordovician limestone. The author put forward, down water level by drainingwater to product safely.