An 82-ton prefabricated tunnel section was lifted into place May 26 as pipe-jacking operations commenced to take Huanping Road under Zhuhai Avenue in Nanping.

Construction of the vehicular tunnel in Zhuhai is the first use of large-section rectangular pipe jacking in South China. The jacking machine, which is named Ling Hang Hao (navigator), is 5 m (16 ft) underground boring through coarse sand and sandy clay. The cross section is 10.42 m (34 ft) wide and 7.57 m (25 ft) high, according to Wei Ningzhe, project chief engineer from China Railway Tunnel Group.

The tunnel will consist of 250 tubes -- 80 of them prefabricated. The Ling Hang Hao can push up to two tubes daily. Work on the 188-m (206-yd) tunnel section is expected to be completed by the end of this year.

Huanping Road is a four-lane 1,588-m (1-mile) urban secondary route in the central area of Nanping Town. It goes from Yanhe Road, along Pingxi Road, and beneath Zhuhai Avenue to Lianquan Road. 

Once open to traffic in 2022, the road is to facilitate travel for residents on both sides of Zhuhai Avenue and help the city become a comprehensive transport hub on the west bank of the Pearl River Estuary.

Ling Hang Hao pipe-drilling machine going under Zhuhai Avenue [Photo by Zeng Yao / Guanhai App]