The world‘s first ultra-high pressure passes through the Yangtze River Tunnel “Wanli Yangtze River First Corridor”

At 9 o'clock on the morning of August 21st, with the huge 'superior' shield machine knife plate breaking out of the earth, a "dragon" with a length of 5468.5 meters deep in the potential Yangtze River was stunned after nearly 400 days and nights. The "Dragon Out of Water" marks the first ultra-high pressure tunnel in the world built by the 14th China Railway Bureau through the Yangtze River Comprehensive Pipeline Tunnel.

The Huainan-Nanjing-Shanghai 1000 KV AC UHV Transmission and Transmission Project is one of the twelve key passages for the control of atmospheric pollution under the State Council, and the Sutong GIL comprehensive pipe corridor project is a key control project for the project, starting from the South Bank(Suzhou). Access Station, At the North Shore(Nantong) ushering Station, with a total length of 5468.5 meters and a shield diameter of 12.07 meters, the National Grid Investment, the Iron Fourth Institute Design, and the China Railway 14th Bureau are responsible for the construction.

It is reported that the Sutong GIL Comprehensive Pipeline Yangtze River Tunnel Project located in Jiangbian, Changshu City, Jiangsu Province is the first time in the world that large-diameter shield tunnels have been applied to power pipe tunnel projects. It is also the world's longest-range GIL innovation project with the highest voltage level, the largest transmission capacity, and the most advanced technology level. At the same time, it is also the first integrated pipe corridor on the Yangtze River that contains municipal pipelines such as electricity, communications, and cable television. Known as the "First Corridor of the Yangtze River", this project has created many world first in the history of power engineering construction and tunnel shield construction.

In the process of tunneling, the underwater Geological conditions are complex, containing methane and other harmful gases, and have difficulties in construction such as high permeability, high density, and high wear. "The deepest construction is 78.4 meters below the Yangtze River, and the maximum water and soil pressure reaches 9.8 times the atmospheric pressure, which is equivalent to a fingernail bearing nearly 20 pounds of weight. It is currently the deepest tunnel in China with the highest water pressure. "The construction person in charge of the China Railway 14th Bureau introduced.

Pipe corridors crossed the embankment twice. The construction is difficult, the safety risk is high, and the construction risk is high. In the face of these worldwide problems, the China Railway 14th Bureau and the National Grid jointly established well-known universities to vigorously carry out technological innovations. Nine invention patents and eight practical patents such as online real-time monitoring of shield scraper wear, Box culvert ventilation, and explosion-proof design have been developed, and nearly 20 papers have been published in the National core journals, and according to the actual passage of harmful gases. For the first time in China, the special design of the shield machine was carried out, which accumulated valuable experience for the construction of underwater large diameter shield tunnel.

"We have to spend more than 12 hours a day with the shield machine to take care of it in all directions to ensure that the" Excellence "equipment is more than 96 % intact," said Chenzongkai, Minister of Electrical and Mechanical Affairs. Since the beginning of the shield machine, it has been digging 14.12 meters per day, 417 meters per month, and 14 months of penetration, creating a new miracle in the world's underwater large-diameter shield tunnel and modern power construction. It was also the 14th Bureau of the China Railway that successfully crossed the Yangtze River for the fourth time after crossing the Nanjing Yangtze River Tunnel, the Nanjing Metro Line 10, and the Wuhan Metro Line 8 Yangtze River Tunnel, occupying half of the country's shield construction across the Yangtze River.

The reporter learned that the project started construction in August 2016 and is scheduled to be completed and put into operation in October 2019. After the completion of the pipe gallery, the installation of gas-insulated metal closed transmission lines, referred to as GIL, will form the world's first ultra-high voltage AC double loop network, just like an oversized electric energy reservoir, which can absorb a large amount of clean energy from energy bases such as Inner Mongolia, Shanxi, and Sichuan. We will reduce 100 million tons of coal used for power generation in the Yangtze River Delta region, reduce pollution emissions, and promote the energy revolution. At the same time, it is very important to improve the ability of telephone calls outside the receiving areas, ensure the safe operation of the power network and achieve ecological priority goals.

Since the shield machine was excavated on June 28, 2017, it has lasted 13 months, with an average daily excavation of 14.12 meters and an average monthly average of 417 meters, creating a new record for the construction of the world's large-diameter shield tunnel. There is no leakage point in the entire tunnel. It is like a natural success. It has received praise from all walks of life and has attracted more than 6,000 experts, scholars, and industry counterparts at home and abroad. Academician Qianqihu praised: "This tunnel is currently the best field management in China, the best physical quality, and the fastest progress in construction of the industry benchmark project. "