TBM RECORDER Mega-TBMs for China double-deck link 8 May 2014
Herrenknecht News Release
Herrenkncht-STEC deal for mega-TBM supply
- China places an order for two mega-Mixshield TBMs with Herrenkncht, with the deal sealed during a German trade delegation visit to the country.
- The order is placed by leading Chinese contractor and manufacturer Shanghai Tunnel and Engineering Company (STEC), which will use the 15.76m diameter Mixshields for delivery of a critical crossing of the Yangtze River as part of wider underground extensions of the rapidly expanding Wuhan Metro network.
- The twin bore double deck tunnel will feature a three-lane highway on the upper level, and Wuhan Metro Line 7 on the lower one.
- The 2,590m long tunnel alignment runs up to 39.5m below the water surface in a complex geology. Water pressures of up to 5.3 bar are anticipated, and the tunnel runs through varying geological formations that feature sand and clay, mixed geology with mudstone, and conglomerates and sand.
- STEC has realized a number of large-scale projects using Herrenkncht TBMs, including several large-diameter road tunnels in Hangzhou and Shanghai. Wuhan, with its population of 10 million, is looking to increase its metro network from three lines and 73km to seven lines and 215km by 2017.
- Last year (2013) Herrenknecht machines achieved four breakthroughs on various crossings of the Yangtze River for a number of different projects in China. In January (2013) a 15.43m Mixshield broke through on the Hangzhou Qiantang River Tunnel for STEC, for completion of the second of two parallel 3.25km drives at depths of up to 27.5m.
Wuhan Metro extensions and river crossings
- This was followed up in May (2013) with the breakthrough of an 11.61m Herrenknecht Mixshield for the China Railway Group as part of excavation works for Nanjing Metro Line 10. Operating at depths of up to 58m below the surface of the Yangtze, earth and water pressure of up to 6.5 bar weighed down on the tunnel and the machine. Herrenknecht engineers equipped the cutterhead with special wheel arms so that cutting tools would be accessible at atmospheric pressure from the rear area of the shield and thus reduce the need for costly compressed air interventions.
- In June (2013) another Herrenknecht mega-machine – this time a 15.43m diameter Mixshield – completed a 3.1km crossing under the Yangtze in Shanghai for completion of the West Changjiang Road River Tunnel, while in the same city but for a different road tunnel project a 14.9m Mixshield completed the first parallel tunnel of the Shanghai Hong Mei Road River Tunnel, also for STEC. The return drive launched in December and is still ongoing.
Tracking the world’s mega-TBMs - TunnelTalk,
State visit to Herrenknecht China - TunnelTalk, Feb 2012
Second mega-TBM river crossing for Nanjing - TunnelTalk, Aug 2011
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