Korea National Railroad has awarded its first turnkey contract to a JV led by Daewoo Corporation for construction of the $290m Young Dong Railroad Relocation Project. The 17.8km long rail project includes a 16.3km long tunnel section that will have a single- track, mixed traffic configuration.
Construction will begin later this year using drill + blast through sedimentary rocks with Coal Measures, including old mine workings and limestone. The tunnel will feature a large radius loop to give the required gradients between Dong-Baek Mountain Station and Do-Ge Station. Computer controlled drilling jumbos and steel fibre reinforced shotcrete spraymobiles are expected.
Tunnelling is likely to proceed simultaneously from five faces, with access from two intermediate adits. A deep shaft required for permanent ventilation will not be used for access during tunnel construction. The construction contract is expected to take eight years.
The tunnel will have a horseshoe section with an 8m span. In the future it will be possible to build a parallel tunnel. The concrete track slab is designed for passenger and freight traffic with diesel or electric traction.
The winning tender design was prepared by Seoul-based consultants led by Yooshin Engineering Corporation, with specialist consultancy services provided by the Halcrow Group (UK) in association with Swiss consulting engineers HBI Haerter.
The tunnel will replace an existing mountain railway built 60 years ago, having many tight curves and tunnels, some of which have become overstressed through time.
