Under the waters of Lake Taihu, in the Chinese province of Jiangsu, lies the longest underwater tunnel ever built in China. Although it serves today as a great solution to decongest one of the most dynamic regions in the country, it has also become, almost by surprise, a tourist destination on its own merits. The reason: a majestic ceiling full of LED lights that change color and an architecture almost designed more to be contemplated than to be functional.
A key point. As we mentioned, the tunnel extends under Lake Taihu, in Jiangsu province, about 50 kilometers east of Shanghai. It aims to connect the expressways of Suzhou, Wuxi and Changzhou to relieve traffic pressure in the lakeside cities, while also serving to boost economic development from the Yangtze River Delta region.
It is also a segment of the highway that connects Shanghai and Nanjing, the former national capital. For this reason, it is a key piece in China’s infrastructure network, but its design and light show have also led to it being transformed into a whole tourist experience.
Figures. With 10.79 kilometers in length, the tunnel had a cost of about 9.9 billion yuanabout 1,230 million euros. Work began in 2018 and lasted almost four years. To build the two-way tunnel, with six lanes and 17.45 meters wide, more than two million cubic meters of concrete were used. For ventilation, there are three complexes distributed along the surface of the lake that guarantee air circulation inside.
The challenge of building under the mud. It was not a simple work. The bed of Taihu Lake is formed by large accumulations of clayey silt, which made it impossible to use conventional excavation methods with tunnel boring machines. The engineering team opted for a cofferdam system: the route was divided into nine sections and, in each one, a temporary dike was built to “create solid ground” and work dry.
Once that section was finished, it was filled with water and moved on to the next. According to collect Tunnels & Tunnelling, one of the biggest challenges was waterproofing the structure, since at some points the tunnel is 20 meters below the lake bed.
Thes LED lights yesThey always improve everythingeither. Their figures and the work that had to be done for something of such magnitude to materialize is impressive. But the tunnel has attracted more and more attention for a clear reason: its roof. Those responsible They installed LED lights on the roof of the tunnel to combat driver fatigue during what would otherwise be a very monotonous journey underground. The panels do not simply project a uniform color, but rather show images that change.
Ventilation and architecture. But the LEDs on the ceiling are not the only eye-catching element. The three ventilation points that emerge on the surface of the lake have been conceived as sculptural pieces. According to China Dailythe one located in the center of the tunnel was transformed into an artificial island 150 meters in diameter; that on the western side, near Mashan, is shaped like a conch; and the one on the eastern side, next to Nanquan, evokes the silhouette of an ancient boat. The most striking is the one known as “Jade Snail”: 45 meters in diameter and 39 meters high, it is equipped with 174,000 LED light points.
A tunnel that generates tourism. The CCCC construction company points out that the Taihu tunnel is now the second highway between Shanghai and Nanjing, and has increased the number of visitors to the tourist enclaves of Lingshan and Nianhua Bay by 50%. The Mashan area, directly connected by the tunnel, is home to the Lingshan Great Buddha, one of the largest in the world and a pilgrimage destination for millions of people.
Liu Xiaoyu, head of Wuxi National Taihu Lake Tourism Resort, pointed out told China Daily that “the tunnel will bring more tourists to the Lingshan Scenic Area and hotels in the area.”
recordd. At almost 11 kilometers, the Taihu is the longest underwater tunnel in China, but it is not the first in the world. The title of longest underwater road tunnel remains with the Norwegian Ryfastwith 14.3 kilometers, connecting the city of Stavanger with the municipality of Strand. On the other hand, if we talk about underwater tunnels in general, the Eurotunnel (which links England and France by rail) retains the absolute record with 37.9 kilometers of submerged section.
Images | CGTN
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