Barrage

BARRAGE (EN: barrage; DE: Sperren, Wasserabdammung; FR: barrage; ES: barrera, dique; RU: барраж) is the method for the protection of the mines and quarries against the underground waters by the method of the complete or partial fencing of the mine workings with the help of the watertight devices. During the barrage, the level of the underground waters within the limits of the watertight devices decreases on the account of the water pumping or drainage, while outside their limits remains near to the natural one, or slightly increases as the result of the backwater.

The barrage ensures the protection of the resources of the underground waters, decreases the operating expenditures for the dewatering (the pumping of the static reserves of water within the limits of the contour of the protected place). The barrage is performed with the help of the infusive, injective, cryogenic, and sheet piling barrage devices (curtains). The infusive (flooded liquid, poured loose soil) devices represent by themselves the narrow vertical workings (slits or trenches), which have been headed by the special machines, namely, trenchers and excavators, to the waterproof sole of the watered sandy, gravelly, or pebbly rocks, and have been filled with clay, clay-cement solution fluid, rolled synthetic material, and so on. They are used in case of the small depth of the embedment of the aquitards (up to 50 metres), orderly (within the horizontal plane and cross section) aquifers, and low permeability of the rocks, which are being developed. The injective (pressurized) devices are constructed by the method of the cementing, claying, silicification, and pitching of the rocks through the injective boreholes. In comparison with the infusive ones, they require the lesser consumption of the plugging material, and are used at the depths of up to several hundred metres. The cryogenic (iced rock) barrage devices are created by the method of the artificial lowering of the temperature of the rocks, and by the freezing of the water, which is contained within them. They are commonly used as the temporary structure during the sinking of the shafts of the mines within any rocks. The sheet piling devices are constructed by the method of the driving of the metal, concrete, and other piles into the sandy-clayish rocks (without the large inclusions of the strong rocks) in case of the small depth of embedment and thickness of the aquifer rocks.

According to the scheme of the placement within the horizontal plane, the barrage devices are sub-divided into the linear and contoured ones, enclosed or non-enclosed ones; according to the scheme of the placement within the cross section, they are sub-divided into the perfect (Figure) ones, which are deepened up to 0.5-1.0 metres into the aquitard, and the imperfect ones, which are not reaching the aquitard (they are used within the hard rocks with the crackedness, which is decreasing into the depth).