The support structure of the Shizimen Tunnel was completed Feb 23, under the Maliuzhou Waterway from Hengqin Financial Island to the Shizimen Central Business District, and the passage is to cut travel time to two minutes when it opens in mid-2023.

Construction site [Photo courtesy Urban Planning & Construction Bureau of the Guangdong-Macao In-Depth Cooperation Zone in Hengqin]

Zhuhai Huafa Group utilized one of the largest shield tunneling machines in China -- 15.7 m (17.2 yd) in diameter -- and overcame high water pressure, a complex hydrological environment, and composite stratum such as soft soil and rock formation. It also had to avoid the south-north Maliuzhou Sea Wall, submerged water pipelines to Macao, and on-shore electricity supply lines to Macao.

Shield tunneling construction began in June 2021, and was completed one and a half months ahead of schedule.

Costing 2.71 billion yuan ($429.6 million), the tunnel runs 2.6 km (1.7 miles) northward from Rongyue Road in Hengqin to Fourth Huizhan (Convention) Road in Wanzai leading to Nanwan Avenue. The cross-waterway section is a duplex structure with traffic lanes and sidewalks on each level.

The tunnel will be the fifth roadway from downtown Zhuhai to Hengqin Island after the Hengqin and Second Hengqin bridges and Maliuzhou and Zhuhai Airport Urban Rail Transit tunnels. Once operational, it will greatly alleviate traffic pressure on the Hengqin Bridge and enhance the investment environment of the Guangdong-Macao In-Depth Cooperation Zone.