Project name: Sutong GIL Comprehensive Pipeline Gallery Project
Constructor: China Railway 14th Bureau
Shield model and diameter: Herrenknecht 12.07m Slurry Shield

Project overview:

Sutong GIL comprehensive pipeline corridor project is a super long distance GIL innovation project with the highest voltage level, the largest transmission capacity and the highest technical level in the world, known as "the first corridor along the Yangtze River". This is the first time in the world that the gas insulated transmission technology is used in the ultra-high voltage transmission channel, providing a new solution for the construction of transmission channels across rivers, seas, densely populated areas and other conditions.

Project characteristics and difficulties:

The two loops of 1000 kV GIL pipeline of Sutong GIL comprehensive pipeline corridor project are about 5.8 km long in single phase and 35 km long in six phases. This through tunnel project starts from the south bank (Suzhou) connecting station and ends at the north bank (Nantong) connecting station. It is 5468.5 meters long, and is the tunnel with the deepest river burial depth and the highest water pressure in China. The deepest burial depth is -74.83m; The maximum water pressure is 0.8 MPa, which is 8 times of atmospheric pressure. The geological conditions in the river are complex, and the construction is difficult. The excavation needs to cross the Yangtze River levee and harmful gas layer, so the requirements for settlement control and risk prevention and control are very high.