A Chinese construction team in charge of excavating a tunnel in one of the longest mountain ranges in the world has embarked on the most challenging part of the mega project – slicing several kilometres through a glacial area.
The 15.7km (9.8 mile) long West Tianshan Super-long Tunnel is part of a major highway connecting southern and northern areas of China’s vast western Xinjiang region. It is expected to help boost trade and tourism and provide a vital link to Central Asia under the Beijing-led Belt and Road Initiative.
The construction team on Wednesday launched a domestically built tunnel boring machine (TBM) to drill the main passageway for the tunnel, state news agency Xinhua reported.
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The 1,800 tonne machine, dubbed «Wensu», was designed and developed by the state-owned China Communications Construction Company. It is 235 metres (771 feet) long and has a diameter of 8.83 metres, making it the widest such machine in use among the tunnel boring projects currently under way at Tianshan, according to Communist Party mouthpiece People’s Daily.
About two-thirds of the 2,500km Tianshan range – which stretches into Kyrgyzstan, Uzbekistan and Kazakhstan in Central Asia – is located in Xinjiang. Its average altitude is about 4,000 metres (over 13,000 feet).
The West Tianshan tunnel will be China’s first to cut a straight path through a glacial area. More than three-quarters, or nearly 12km, will run through rock under 1km of ice, with some sections under as much as 2.4km of ice.
Wensu is also the most advanced TBM to traverse the Tianshan range, a seismically active region with average temperatures of about minus 23 degrees Celsius (minus 10 Fahrenheit) in the winter. The geological conditions present unique safety and environmental challenges for tunnel boring, including water inrush, rock bursts and variable ground temperatures, Xinhua reported in April.
Nearly 12km of the tunnel will run through rocks under 1km of ice, with some sections under as much as 2.4km of ice.
Photo: QQ.com© Provided by South China Morning Post
Construction on the tunnel started in September and is scheduled for completion in 2026. The project is the most important segment of the 237km Zhaosu-Wensu or G219 highway, connecting Zhaosu county in northern Xinjiang to Wensu county in the south, according to People’s Daily.
Due to open to traffic in 2027, the highway will be part of a major transport route linking China to Russia, Kazakhstan, Tajikistan, Kyrgyzstan and Pakistan, as well as a key connection between Xinjiang and Tibet.
China has started work on several highways and tunnels in Xinjiang in recent years, including the Tianshan Shengli tunnel – a crucial section of the 1,300km Urumqi-Yuli Expressway linking the regional capital to Yuli county in central Xinjiang.
The 22.1km passage will be the world’s longest such tunnel when the highway opens to traffic late next year.
