Two Herrenknecht Mixshields with an excavation diameter of 15.76 meters for crossing under the Yangtze River in Wuhan have built a twin-tube, two-story tunnel. A three-lane road runs on the upper deck, with metro line 7 below. The launch of the first of the two TBM giants was celebrated in the presence of political dignitaries on April 27, 2016.
The 2,590 meter long tunnel alignment runs up to 38 meters below the river surface in extremely complex ground conditions. On the one hand, high water pressure of 5.3 bar had to be dealt with. On the other hand, the tunnel runs through different geological formations, partly entirely sand and clay, partly a mixed geology of argillite, conglomerates and sand.
The two Mixshields are equipped with accessible cutting wheels. Thanks to this sophisticated concept, the cutting tools can be changed quickly and safely under atmospheric pressure. The cutting wheels were manufactured in Herrenknecht's Schwanau plant and transported to China, where at customer Shanghai Tunnel Engineering Co., Ltd (STEC) factory assembly was carried out.
In mid-April 2018 the first of the two machines crossed the finish line and in late May the second reached its target shaft. Despite the difficult geological conditions, the miners achieved weekly best performances of 94 meters with each of the machines.
On October 1, 2018 already, the structure was ceremoniously inaugurated and opened to traffic.
The 10 million inhabitant metropolis of Wuhan is the most important regional and national transport hub in central China. A highly efficient subway network, currently consisting of nine lines with a total length of 288 kilometers, carries between 2 and 3 million people a day through the city. Further extensive expansion and new construction will help keep up with population growth.
Wuhan Sanyang Lu Yangtze Tunnel set the benchmark in terms of collaboration between Herrenknecht and STEC. Though the difficulties that confronted us during tunnelling seemed insuperable, we made the final breakthrough possible in June 2018, based on our technical expertise, project experience and our determination to succeed.
Zhang Yan, Chairman of STEC
|Column 0||Column 1|
|Project||Wuhan Metro Line 7 SanYang Road River Crossing, China|
|Contractor||Shanghai Tunnel Engineering Co., Ltd.|
|Year||2016 - 2018|
|Application||Metro and three-lane road on two levels|
Sand, clay, mudstone, compacted conglomerates
|Tunnelling lengths||2578m + 2,590m|
|Machine data||2x Mixshield:
Excavation diameter: 15,760mm
Lining Method: Segmental lining
Cutterhead power: 5,600kW
We are ready!