Tunnel opens to link Xuhui and Minhang

STEC Shanghai Urban Construction Municipal Engineering Group / Ti Gong

A new tunnel beneath the Middle Ring Road at Tianlin Road opened on Friday night to better connect Xuhui and Minhang districts, benefiting over 200,000 residents and commuters.

The 1-kilometer tunnel officially opened at 10pm after about three years of digging and construction. It becomes a major artery between the two districts, according to STEC Shanghai Urban Construction Municipal Engineering Group.

The tunnel, including an 86-meter section beneath the Middle Ring Road, has three vehicle lanes and two bicycle lanes. It has a design speed of 40 kilometers per hour for vehicles.

Previously, drivers and pedestrians on Tianlin Road had to detour to parallel streets because the ring road cuts the road off, causing congestion, especially during rush hours.

A large number of vehicles were often jammed on nearby Yishan and Caobao roads during the morning and evening peak times every day, according to traffic police.

The tunnel features a reversible vehicle lane to cap tidal traffic flows in the morning and evening peaks. It is expected to reduce the driving time across the ring road to five minutes from about 40.

The tunnel is beneath the core region of the Caohejing High-Tech Industrial Park, home to a large swathes of office high-rise buildings.

Over 20 water, electrical and communications lines are buried beneath the ring road.

To avoid affecting the operation of the ring road and pipelines, the construction firm applied an innovative “tube pumping” method to prevent land subsidence as well as to reduce vibration and noise.

The method also shortens the schedule by 30 percent comparing with conventional digging by a shield.

Under the new method, workers pumped 62 steel tubes into the soil under the ring road to cut a rectangle shape 20 meters wide and 6 meters high. A box-culvert was then dug out of the soil within the rectangle to build the tunnel.

Construction started in October 2016 while the first steel tube with a diameter of 80 centimeters was pumped into the soil beneath the ring road in September 2017.