The second tunnel through Big Hengqin Mt was broken through on March 30 after 21 months of challenges which lately includes the COVID-19 outbreak.

Work resumed on Feb 20 with around-the-clock shifts to get back a schedule calling for opening by Nov 30. Considering epidemic prevention and control, an enclosed management mode was adopted. Three-arm jumbo drill, concrete spray, and arch installation trolleys were also used to increase efficiency and safety.

Big Hengqin Mt Tunnel sees daylight [Photo by Zhong Fan / Guanhai App]

So far, the project team has beaten typhoons, high temperatures inside the tunnel, and nighttime blasting restrictions. They also dealt with technical challenges to go over Chimelong Tunnel, under Zhuhai Airport Urban Rail Transit Phase II and Wangtiantai Reservoir, and through five fault fracture zones. 

Nonetheless, constructor China Railway 16th Bureau Group adhered to a green concept by introducing Building Information Modeling (BIM) technology and an intelligent monitoring system for informatization and safety management. This, the first phase, is invested by China Railway Construction Investment Group.

Big Hengqin Mt Tunnel is 4.9 km (3 miles) long from Central Avenue between Caihong and Xiangjiang roads to Changlan Bay. It is the southern extension of north-south Central Avenue, which is part of Hengqin New Area's skeleton road network, and a key passage connecting Hengqin Island to the Southern Reclamation Area.