Milestone for tunnel to link Xuhui and Minhang

THE world’s biggest box culvert machine was put to work yesterday on a tunnel which will connect Xuhui and Minhang districts.

Concrete box culverts, over 19 meters long and 6 meters tall, will be inserted into the soil beneath the Middle Ring Road at Tianlin Road for the 1-kilometer-long tunnel. Once completed, the tunnel is expected to ease traffic congestion in the Caohejing area.

Completion is set for the end of 2018 and the tunnel will open to the public in March 2019, according to STEC Shanghai Urban Construction Municipal Engineering Group.

The tunnel will have three motor vehicle lanes and two bicycle lanes, the group said.

Drivers and pedestrians on Tianlin Road currently have to detour to parallel streets because the ring road cuts the road off, causing congestion, especially during rush hours. Vehicles regularly become jammed on nearby Yishan and Caobao roads during morning and evening commutes.

Workers are digging beneath the busy ring road without affecting its operation, said Wang Huan, a senior engineer working on the digging project.

Compared with traditional digging methods, the box culvert method can shorten the schedule as well as reduce costs by 30 percent, Wang said.

Over 60 hollow steel tubes with a diameter of 80 centimeters have been drilled into the soil beneath the ring road, an innovative technique to prevent subsidence as well as reduce vibration and noise.

The steel tubes cut a rectangle shape and the box culvert was then pushed into the soil with three digging machines to build the tunnel, said Niu Jie, the technical supervisor for the project.