Beiheng Passage ahead of schedule

The largest shield machine in Shanghai which has been digging the tunnel for the Beiheng Passage completed its work for the year, seven days ahead of schedule, deep beneath Jiangsu Road.

The 600th section was slotted into place yesterday, according to Shanghai Chengtou Group. Each section can be up to 2 meters long.

The machine set out from Zhongshan Park in June, and encountered problems almost immediately as it passed under residential complexes near the park.

Zhaofeng Villa was built in the 1930s and its foundations are not as stable as those of newer buildings. The shield machine is enormous — around 20 meters in length. Minimizing the impact on residents became a huge task.

Engineers went to the communities and examined every house. Automatic monitoring ensured that as the machine dug through the area, structural shifts were controlled within millimeters.

The problems were not all overground. The tunnel passes underneath Metro Line 11. At the junction of Jiangsu and Changning roads, it is only 7 meters below the Metro tracks. Trains on Line 11 reduced their speed to prevent vibrations from affecting the digger’s progress.

Although the machine has finished its years’ work, three more Metro lines lie ahead and hundreds of residential buildings.

After completion, the 19.1-kilometer passage between Beidi Road and Zhoujiazui Road will link Changning, Putuo, Jing’an, Huangpu, Hongkou and Yangpu districts.

Ti Gong