Electrowatt Infra AG has been awarded an extension to their existing consultancy contract for the Zhong Nan Mountain Highway Tunnel in China, claimed to be the world’s longest twin tube highway tunnel.
The scheme features twin road tunnels 18km long, with two lanes per tube. T&TI was told each tube is 7.5m high with a carriageway width of 8.5m and a 1.2m wide walkway on each side. Emergency arrangements include pedestrian cross passages at 250m centres and vehicular cross passages for emergency vehicle access at 750m intervals. Both ends of each cross passage can be closed. In addition, lay-bys are planned for every 500-750m on the side of each tube.
The tunnel, also referred to as the Qin Ling Zhong Nan Mountain Super-Long Tunnel, is the major part of the new Xian-Ankang Expressway in Shaanxi province. Electrowatt Infra, part of the Jaakko Pöyry Group’s Infrastructure & Environment business group, was engaged by client SQZHT in 2004 to review the ventilation system, mechanical and electrical systems and safety aspects of the tunnel. As part of the latest consultancy contract, awarded in late 2005, the company was commissioned to carry out a risk assessment relating to the tunnel operation, including suggesting ameliorating measures.
The design driving speed in through the tunnels is 80km/h. The project is due to be completed and opened for traffic by October 2007, although current plans call for the west running tunnel to be opened for traffic by October this year.
