DRAINAGE SYSTEM IN GALLERY

PURPOSE:To control the maintenance of a pump and piping by removing earth and sand from sucked from a working face part in a gallery, preventing the tip of the piping from deposition of calcium and giving pH treatment to the water when the water is drained to the outside of the gallery by a horizontal sand pump. CONSTITUTION:Water in a gallery like water collected in a working face part 2 of the gallery 1 in tunnelling and springing out of the natural ground and working water is sucked by a submerged pump 4 to be sent to a dehydrating system 6 through a piping 1 Then, solids separated from the water in the gallery by an earth and sand separator 6 for example are discharged together with waste like earth and sand caused by excavation to the outside of the gallery. While the water in the gallery is subjected to pH treatment, calcium included in the water in the gallery is removed. Further, a system for transport water content accumulated in a water tank to muddy water processing facilities 8 outside the gallery is composed of horizontal sand pumps 9 provided in parallel and connecting pipes. Thus, the horizontal sand pump 9 provided with a tough impeller is used to reduce the number of times of replacement and cleaning of the pump so that the efficiency can be improved by expanding the operating space due to the drainage.