A new record building infrastructure project was opened in China this Friday. The Tianshan Shengli Tunnel, which stretches through the central part of the Tianshan mountain range, connecting the region’s capital, Ürümqi, with Yuli County to its south, with a length of 22.13 kilometers, surpasses all previous records for highway tunnels.
China’s record holder is slightly shorter than Norway’s Lærdal Tunnel (24.51 km), which holds the title of the longest road tunnel overall, but that tunnel was built with an ordinary two-lane road at its core. Tianshan Shengli (translated as “victorious”) is, in contrast, designed around a high-capacity highway with two parallel tubes that enable faster and safer traffic.
An engineering challenge
The construction of this tunnel was a huge challenge due to the extreme geological conditions. The tunnel is located at a maximum depth of 1,112 meters below the mountain ridge and passes through as many as 16 fault zones. To cope with the high rock pressure and risk of collapse, engineers used advanced tunnel boring machines. Machines from Chinese development enabled faster progress, drilling 20 to 30 meters per day, which reduced the construction time by about 25% compared to traditional drilling and blasting methods. In addition to its length, the tunnel is also distinguished by the deepest vertical ventilation shaft ever built for a road tunnel, which has a depth of over 700 meters.
The opening of the tunnel will bring a revolution in the transport connection of the Xinjiang region. Before construction, travel across the Tianshan mountain range took hours, often made difficult by snow and ice during the winter. Now that trip has been reduced to just a 20-minute drive through the tunnel.
The new tunnel will provide a reliable traffic connection throughout the year, eliminating the winter blockages that previously paralyzed traffic and supplies. With a total investment of over 5.6 billion euros, the project symbolizes China’s ambition in developing infrastructure in remote and poorly connected regions there.