Typical roof water disasters and its prevention & control technology in the north of Ordos Basin

In order to find out the formation mechnisum of the typical roof water disasters in the north of Ordos Basin, and put forward corresponding prevention measures,based on the analysis of regional thickness,existing characteris- tics,ditribution range and hydrogeological parameters of aquifer,combined with the water inrush feature of different types of water disasters,it found that the typical roof water disasters at west margin,east margin and north margin in re- search region are different,and typical water disasters includs the water disaster from bed-separation space,water and sand inrush with thin bedrock and the water disaster of ultra thick glutenite aquifer. With the investigation of aquifer sedimentary characteristics and hydrogeological conditions,combined with formation element and water disaster charac- teristics,the formation mechanism of typical water disaster was found out. “Sheaf-like borehole and targeted drainage” are the effective measures for preventing and controlling water disaster from bed-separation space. Water drainage and grouting can be used to prevent water and sand inrush with thin bedrock. Water drainage and strengthening the drain- age system can be applied to avoid the water disaster of ultra thick glutenite aquifer. In practice,if the water disaster condition is identified correctly and the measure for water disaster prevention and control will be effective.