Known as the "most difficult railway tunnel to build", an important milestone has been reached →

Author: Shi Xiangqi and Li Chuanfu

Amid the mountains of Yunnan Province, a great project is in full swing - the Gaoligong Mountain Tunnel of the Dali-Ruili Railway, known as the "most difficult railway tunnel to build". This tunnel is not only an important part of the China-Myanmar International Railway, but also a key project serving the construction of the "Belt and Road". On October 5, 2024, the project ushered in an important milestone: the completion of the first underground mixing station for railway tunnels in China.

The Gaoligongshan Tunnel is 34.538 kilometers long and has a maximum buried depth of more than 1,100 meters. It is China's first railway tunnel that crosses the Hengduan Mountains. The geological conditions of the tunnel are extremely complex, including almost all adverse geological conditions and major risks, so it is known as the "most difficult railway tunnel to build" in the world. In order to meet this challenge, engineers adopted the construction plan of "through horizontal guide + 1 inclined shaft + 2 vertical shafts" to shorten the construction period and increase the working surface.

Behind this grand project is the hard work of more than 1,300 builders. They worked hard on 17 working faces more than 600 meters underground to speed up construction. Their efforts not only shortened the distance between Dali and Ruili physically, but also spiritually connected the economic, trade and cultural exchanges between Yunnan and Southeast Asian countries.

The completion of the mixing station is the result of technological innovation and solution innovation of China Railway Tunnel Bureau Group Construction Co., Ltd. This underground mixing station is located in the No. 2 vertical shaft of Gaoligongshan Tunnel of Dali-Ruili Railway at a depth of 640.22 meters. Its completion has overturned the traditional ideas and spatial layout, and is a bold innovation in the history of domestic railway tunnel construction. The completion of the mixing station not only improves the production efficiency of concrete, but also ensures the simultaneous construction of multiple working faces, which is of great significance to improving the construction progress and quality.

The construction of Gaoligongshan Tunnel is a great challenge in the history of China's railway construction and a demonstration of China's engineering and technical strength. Its completion will shorten the driving time from Dali to Ruili from the current 6 hours to about 2 hours, greatly promoting economic development and personnel exchanges in the areas along the line.

In addition, during the construction of Gaoligong Mountain Tunnel, Chinese railway builders also faced extreme construction environments of high temperature, high pressure and high humidity. They not only had to deal with complex geological conditions, but also had to solve problems such as drainage, ventilation and cooling. Working more than 700 meters underground, the builders created a huge underground working space, which is the largest and most complex "underground car factory" in China's railway under construction.

With the gradual completion of the Gaoligong Mountain Tunnel, the full opening of the Dali-Ruili Railway is just around the corner. This will not only bring more convenient transportation conditions to the Yunnan region, but also provide a more solid foundation for exchanges and cooperation between China and Southeast Asian countries. The construction of the Gaoligong Mountain Tunnel is a vivid practice of China's railway "going out" strategy under the "Belt and Road" initiative, and it is also a manifestation of the wisdom and courage of Chinese railway builders.