The giant dragon crossing the Yellow River: China's largest diameter underwater shield tunnel begins shield excavation!

Author Li Chuanfu

On September 1, 2024, on the north bank of the Yellow River in Jinan City, Shandong Province, as the cutterhead of the "Shanhe" shield machine slowly started, the largest diameter underwater shield tunnel in China, the Jinan Huanggang Road Yellow River Tunnel, officially began its journey across the Yellow River. This is not only a technological breakthrough, but also a challenge to human wisdom and courage.

Shield tunneling technology is an advanced method of digging tunnels underground or underwater. It uses a huge, mobile mechanical device, the shield machine, to dig tunnels and install tunnel linings at the same time. The application of this technology makes tunnel construction no longer restricted by terrain and landforms. It can build channels connecting two places underground in cities, under rivers, lakes and seas, and even in mountains.

The working principle of the shield machine is similar to that of a huge earth drill. It assembles prefabricated concrete segments into tunnel walls while excavating, thus forming a solid circular tunnel. This construction method not only improves construction efficiency, but also greatly reduces the impact on the surrounding environment.

The Shanhe TBM, as the largest TBM in China, has a diameter of 17.5 meters and a total weight of more than 5,200 tons. This giant TBM not only represents the top level of China's TBM technology, but also symbolizes China's manufacturing strength. Its launch marks another major progress in China's large-scale infrastructure construction.

The Shanhe shield machine is equipped with advanced equipment such as a pressurized composite cutterhead, a telescopic main drive, and a telescopic camera for the excavation chamber, and its overall assembly level has reached the world's advanced level. The shield machine is also equipped with "five senses and one brain" intelligent equipment systems such as advanced geological prediction, stratum interface identification, gas environment monitoring, cutter wear monitoring, synchronous grouting detection, and auxiliary decision support system, which comprehensively enhance the intelligent perception ability of the Shanhe shield machine. Through the intelligent decision-making of the "brain center", it can greatly reduce the safety risks of shield construction and more effectively adapt to the complex and changeable construction environment and high-standard technical requirements.

The cutterhead of the Shanhe is painted with a pattern of the auspicious beast Kylin, which symbolizes good luck and strength. The hoisting of the cutterhead downhole is the most important part of the entire shield machine hoisting and assembly stage, and it is also the most difficult and dangerous process. With the help of two crawler cranes with lifting capacities of 800 tons and 400 tons, the cutterhead slowly "stands up" from the ground, completes the "air rotation", and then accurately descends to the predetermined position of the starting shaft, and accurately "fits" with the shield machine.

The Jinan Huanggang Road Tunnel is 5,755 meters long, of which the shield section is about 3,290 meters long. The completion of this tunnel will greatly improve the traffic conditions on both sides of the Yellow River in Jinan and promote the development of the regional economy. The design and construction of the tunnel fully consider the special geological conditions and hydrological environment of the Yellow River, ensuring the safety and reliability of the project.

Every progress in shield tunneling technology is inseparable from the promotion of scientific and technological innovation. From the initial manual excavation to today's fully automated shield machines, technological innovation has made tunnel construction more efficient and safer. In the future, with the continuous emergence of new materials and new processes, shield tunneling technology will be more perfect and able to cope with more complex geological conditions and environmental challenges.

The construction of the Huanggang Road Tunnel in Jinan City is a demonstration of China's scientific and technological strength. It not only connects the two sides of the Yellow River, but also connects the past and the future, showing the power of science and technology and the hope of mankind. With the continuous advancement of science and technology, we have reason to believe that there will be more miracles waiting for us to create in the future.

Under the guidance of science and technology, we are moving towards a more convenient and better future. Let us wait and see, and look forward to the "Shanhe" shield machine writing a new legend under the Yellow River.