Construction of the new Mansky tunnel on the Abakan Ц Taishet section of the Krasnoyarsk Railway.
Start of construction Ц 2005, completion of construction Ц July 2014.
Tunnel length Ц 2465 m, service gallery length Ц 2471 m.
Scope of work: new tunnel construction, service gallery construction parallel to existing tunnel 59 meters away.
A service/drainage gallery has been built from September 2007 to April 2010 using the tunneling and drilling/blasting driving techniques. The Lovat RME-139SE Tunnel Boring Machine with a cutting diameter of 3.56 meters has driven 2,166.2 meters of the gallery, and prefabricated reinforced concrete lining was installed simultaneously with the tunneling. A tunnel section of 300.74 meters was driven using the drilling and blasting technique, with the permanent lining provided by concrete spraying.
Construction of the new tunnel using rock tunneling method was started in October 2011. After driving the cap part of the tunnel through the 120-meter-long section in June 2012 and after the preparatory operations and the tunnel-boring machine assembly had been completed, the builders started the tunneling using the Lovat-RME375SE Tunnel Boring Machine with a cutting diameter of 9.54 m. The 120-meter-long bottom part of the tunnel was first driven by the tunnel-boring machine and the tunneling was then conducted over the whole cross-section. The New Mana Tunnel is built under challenging geological conditions. The tunnel has been driven within the initial 120-meter-long tunneling section mainly through the rock disintegrated to detritus. The rest of the tunnel is driven in hard rocks with a hardness ranging from f=16 to f=20 (maximum on the Protodiakonov hardness scale). Tunnelling work is completed in July 2013.