In order to minimize the gushing water in the shaft,a pre-grouting technology was used at working face to control underground gushing water,thus being able s moothly to complete the construction work of the rest 130m section of the shaft under more complicated hydrogeological conditions.
For small working place and large quantity water flush in deep mining, upper banch understripping, and no deep dewatering in Shilu open pit mine,the mining efficiency declined, mining costs increased largely, and loss in economy.
Dredging water tunnel long 18m is diged, water flush of 31404 breakage face flowed into workedout section of 31402 breakage face, water pressure reducted, proper production gained guarantee at the breakage face, and risk of water flush reducted when next branch seam is mined, safety factor and reliability inceased.
Moreover, karst terranes are quite often haunted by a series of engineering problems, such as water gushing into mines or transportation tunnels; leakage from reservoirs; and failure of building foundations.
Hundreds of water inrush accidents have occurred and over 30 mines have been flooded, resulting in heavy economic losses and casualties.
Hundreds of water inrush incidences have occurred in which a large amount of water suddenly flows into tunnels or working faces under high potentiometric pressure and over 30 mines have been flooded over the last 20?years.
When the water pressure in the underlying aquifer exceeds Phf, a wedging effect takes place within the fractures of the geological barrier and, as a result, water inrush occurs.
Based on the test results, a new safety criterion for water inrush was derived for mines and it has been successfully applied to mining practices with the minimum effort of dewatering in the karst aquifer.
Water inrush and environmental impact of shallow seam mining