China opens its longest underwater tunnel beneath Lake Taihu

Last month, China officially unveiled its longest underwater tunnel to date, crossing Lake Taihu in Jiangsu province. Spanning 10.79 kilometers, this impressive project aims to ease traffic congestion in the Yangtze River Delta region and boost local economic growth. Beyond its practical purpose, the tunnel has quickly become a tourist attraction thanks to its eye-catching LED-lit ceiling, designed to provide a mesmerizing visual display.

Located about 50 kilometers east of Shanghai, it links the highways of Suzhou, Wuxi, and Changzhou, forming part of the route connecting Shanghai and Nanjing. The total investment exceeded 9.9 billion yuan, roughly 1.23 billion euros, with construction starting in 2018 and taking nearly four years. The tunnel features six lanes and measures 17.45 meters wide, built with over two million cubic meters of concrete.

Constructing beneath Lake Taihu's muddy bed was no easy feat. The presence of clay silt prevented the use of traditional tunnel boring machines. Engineers adopted a cut-and-cover approach, dividing the project into nine sections and building temporary dikes to work in dry conditions. After completing each section, it was flooded, and work continued on the next. Waterproofing was a major challenge, especially since parts of the tunnel are located 20 meters below the lakebed.

The most striking feature is its ceiling, fitted with LED lights that produce a dynamic light show. This design aims to reduce driver fatigue and turn a routine crossing into an engaging visual experience. The combination of advanced engineering and creative design has made this infrastructure a symbol of China's technological and cultural progress.