The world's largest diameter high-speed shield machine "pilot" has broken through 5,000 meters

On March 17, the Chongtai Yangtze River Tunnel "Pilot", independently developed by China and the world's largest diameter high-speed iron shield machine, was excavated to the 2500 ring, breaking through the 5000 meters mark, leaving only 660 meters from the center of the river.

Chongtai Yangtze River Tunnel is one of the control projects of the high-speed railway from Shanghai to Nanjing to Hefei, connecting Chongming District of Shanghai and Taicang City of Jiangsu Province. The tunnel length is 14.25 kilometers, including 13.2 kilometers of shield section. It adopts the design of single hole and double track, and has the longest tunneling distance of 11.3255 kilometers in the world. Designed at 350 km/h, it is the world's fastest underwater tunnel; The tunnel reaches 89 meters under the Yangtze River, making it the deepest tunnel under the Yangtze River. The tunnel is constructed and managed by Huhang Passenger Special Company and constructed by China Railway Tunnel Bureau. After the project is completed and operated, it will realize the feat of high-speed rail crossing the Yangtze River without slowing down.

The shield section of Chongtai Yangtze River Tunnel from Chongming District No. 3 to Taicang City No. 2 adopts the "Pilot" shield machine for tunneling construction. The shield is 148 meters long, weighs about 4000 tons, and the cutter head diameter is 15.4 meters. The shield machine is equipped with the world's "strongest brain", which integrates nine intelligent construction technology achievements such as intelligent perception, intelligent excavation and intelligent assembly. It has ultra-long and reliable service capability, keen perception ability, intelligent decision-making control ability and acceleration ability, and has the ability of "independent thinking, intelligent analysis and independent judgment". Realize "manned, unmanned" intelligent construction.

Since the launch of the "Pilot" shield machine on April 29, 2024, with the goal of "building a world-class ultra-large diameter shield crossing the Yangtze River benchmark project", it has actively carried out scientific and technological research on many problems and challenges such as ultra-large diameter and ultra-long distance single-head excavation, ecological environment sensitivity, hard cement formation, alternation of strong and weak permeable formation, and alternation of erosion and silt changes. Increasing the cultivation and application of new quality productivity, forming a shield tunnel intelligent construction 2.0 technology system, deeply embedding intelligent concepts and technologies into the whole process of Chongtai Yangtze River tunnel construction, creating a 15-meter class ultra-large diameter shield the fastest tunnelling 28 meters in a single day, the fastest tunnelling 718 meters in a single month.

The Shanghai-Nanjing to Hefei high-speed railway is the eastern section of the Shanghai-Chongqing-Chengdu high-speed railway and an important part of the national "eight vertical and eight horizontal" high-speed railway network along the Yangtze River high-speed rail channel, which undertakes the transport of the main network passenger flow along the Yangtze River channel and the coastal and Beijing-Shanghai channel parts through to Shanghai passenger flow. After the completion of the project, a new fast channel will be built between the Shanghai metropolitan area, Nanjing Metropolitan area and Hefei metropolitan area, which is of great significance to creating a "Yangtze River Delta on track", optimizing the layout of the railway network along the Yangtze River region, serving the high-quality development of the Yangtze River Economic Belt, and promoting the high-quality development of the Yangtze River Delta integration.