Rbte Drainage system in tunnel

Drainage system in tunnel

1. Presentation On Drainage system in tunnel

2. Drainage of tunnel’ means controlling of water during and after the construction of the tunnel. Controlling of water is attained by preventing excess quantity of water from entering the tunnel and removing the water that does enter. In driving a tunnel water comes from two sources Wash water used for washing drill holes. Ground water or sub soil water.

3. Drainage system is divided Temporary Drainage system Open ditch drainage system Pumping system 2. Permanent Drainage system Central drain system Corrugated sheet roof with side drains Single side drain system

4. Central drain system This system is suitable when the water coming through the roof and the side walls of the tunnel is sufficiently low. In this system a central drainage ditch is constructed longitudinally sloping towards the portals from where they could be pumped out of the tunnel by suitable pumps

5. Single side drain system This system is adopted where the quantity of water entering the tunnel is small. The method is adopted in case of tunnels carrying a single lane highway or railway track. For a draining water a single side drain of sufficient capacity is provided.

6. Open ditch drainage system This is the simplest method through which water may be moved i open ditches, with proper slopes, to the portals and may be pumped out from there. It is suitable in impervious soils and rock bases.

7. Pumping system In case of pumping system the quantity of water that accumulates is collected in sump wells and pumped out of the pump. For long tunnels, it may be necessary to have more than one sump used. There are two types of pumps used Piston type Centrifugal type

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