Tunnel dug beneath Middle Ring Road with creative method
The world’s biggest box culvert machine, over 19 meters long and 6 meters tall, digs through the soil beneath the Middle Ring Road for the 1-kilometer-long tunnel on Tianlin Road.
Excavation was completed on yesterday on a tunnel beneath the Middle Ring Road at Tianlin Road to better connect Xuhui and Minhang districts.
The world’s biggest box culvert machine dug fror 1 kilometer beneath the busy ring road.
The tunnel, including an 86-meter section beneath the Middle Ring Road, will have three vehicle lanes and two bicycle and pedestrian lanes with a speed limit of 40 kilometers per hour.
Drivers and pedestrians on Tianlin Road currently have to detour to parallel streets because the ring road has cut the road off since 2005, causing congestion, especially during rush hours. A large number of vehicles snarl up on nearby Yishan and Caobao roads during rush hours every day.
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 minutes.
The Tianlin Road tunnel, including an 86-meter section beneath the Middle Ring Road, will have three vehicle lanes and two bicycle and pedestrian lanes. It has a designed speed of 40 kilometers per hour for vehicles.
The Tianlin Road tunnel, including an 86-meter section beneath the Middle Ring Road, will have three vehicle lanes and two bicycle and pedestrian lanes. It has a designed speed of 40 kilometers per hour for vehicles.
The tunnel is being built in the core region of the Caohejing High-Tech Industrial Park being housed to a large swathes of office high-rise buildings. Over 20 water, electricity and intercommunication pipelines are buried beneath the ring road.
To avoid affecting the operation of the ring road and pipelines, the manufacturer has applied an innovative “tube pumping” method to prevent land subsidence as well as to reduce vibration and noise. The method can also shorten the schedule by 30 percent comparing with the traditional digging by a shield.
Under the method, workers keep pumping a total 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 will then dig out the soil within the rectangle to build the tunnel.
Construction started on the tunnel in October 2016 while the first hollow steel tube with a diameter of 80 centimeters was pumped into the soil beneath the ring road in September 2017.
The project has become a major trial operation for the innovative digging method, which could be expanded to many other tunnel and subway projects in the city, said Xin Zhenggang, deputy project manager for the tunnel project.
An artistic rendition of Tianlin Road tunnel, which is due to open by March of 2019.
