Han Ximin

ximhan@126.com

A TUNNEL-BORING machine (TBM), 15.53 meters in diameter, has started work on the Mawan undersea tunnel project from the Dachan Bay area Thursday, accelerating the progress of the project.

The TBM is about 140 meters long, five stories high and weighs 4,650 tons. The cross section of the machine is about six times the size of regular TBMs used for Metro work.

The tunnel project is part of the 8.05-kilometer Mawan Cross-sea Passage, which will play a positive role in improving the road network outside the Qianhai area, realizing the separation of passengers and goods in the Qianhai area, and promoting the transport connectivity in the Guangdong-Hong Kong-Macao Greater Bay Area.

The passage starts at the intersection of Mawan Boulevard and Yueliangwan Boulevard and ends at the Dachanwan Toll Station of the Guangzhou-Shenzhen Riverside Expressway and the intersection of Jinwan Boulevard and Xixiang Boulevard. It includes a 2.5-kilometer road in Qianhai, a 1.1-kilometer tunnel and a 4.45-kilometer road in the Dachan Bay area, according to the construction plan.

The underground section is designed as an urban highway, with six lanes in two directions and a designed speed of 80 kilometers per hour. The ground-level section is designed as an urban trunk road, with six lanes in two directions and a designed speed of 40 kilometers per hour.

As the first mega-undersea tunnel in Shenzhen, the passage is expected to alleviate the traffic pressure in the Qianhai area when put into operation in 2023, according to Zhao Yong, an engineer with the city’s public infrastructure construction center.

At the same time, freight traffic will be diverted away from the coastline, which will open up coastal space.