The Belt and Road Initiative has been implemented around the world, contributing to the Central Asian countries' infrastructure improvement and improvement of people's livelihood. Central Asia is the place where the Belt and Road initiative was initiated. Over the past ten years, China and Central Asia have carried out equal, pragmatic and efficient cooperation, and the joint construction of the Belt and Road has achieved fruitful results.

Among them, the Kamchik Tunnel Project, the longest tunnel in Central Asia, Uzbekistan's Anglian-Pabu Railway, designed and completed by the China Railway Sixth Institute, is not only a demonstration project for the joint construction of the Belt and Road Interconnection Cooperation, but also an important Silk Road project. The China-Central Asia-Europe component of the international transport corridor has completely changed the way tens of millions of people travel, making life better for people along the Silk Road.

The Kamchik Tunnel in Uzbekistan is the first railway tunnel in the history of Uzbekistan, known as the Uzbek President No. 1 Project. The tunnel, with a total length of 19.26 kilometers, is located in the Babisko area of Namangan Province, the Federal Republic of Uzbekistan, and is the throat of Uzbekistan's national railway network. For the local people, it turns out that traveling from Tashkent to Fergana requires a 150-kilometer detour through other countries. Now it only takes 3 hours, which is 6 hours less than before, which has greatly promoted the Ukrainian railway cause and economic and social development.

The Kamchik Tunnel passes through a large mountainous area, with steep terrain and complex geological structures, making construction extremely risky and difficult. The part of the tunnel that goes through the mountain is 20 kilometers long. The design, construction, and technical requirements are extremely high, and the engineering volume and cost are huge, which has caused the tunnel to be shelved for a long time.

Faced with unfavorable factors such as difficult design, tight construction schedule, language barrier and environmental impact, the tunnel design team of China Railway Sixth Institute was ordered to go to Uzbekistan to carry out survey and design work as soon as possible.

The lowest temperature in the tunnel site area of the Kamchik Tunnel Project is -42°C, and the average temperature in the coldest month is -16°C. It is located in an earthquake intensity zone of Ⅸ degree. The maximum buried depth of the tunnel is 1270 meters, and the strength-stress ratio of the surrounding rock reaches 2.7-7. During the construction process, more than 3,000 rockbursts of moderate intensity occurred, which caused great interference to the tunnel construction and seriously affected the normal construction and progress of the tunnel. How to effectively predict and protect against rockbursts is the main factor controlling the safety of tunnel construction and the progress of the project. If it is not handled properly, it will easily cause serious damage to the excavation surface, equipment damage, and even heavy casualties. The anti-freezing and heat preservation of the tunnel entrance and the drainage ditch outside the tunnel, the shallow buried tunnel and the anti-shock absorption measures of the fault zone are the key to the safe operation of the tunnel in the later stage. He Weiguo, the chief expert, deputy chief engineer of China Railway Sixth Institute, and general project leader recalled.

In order to speed up the construction progress, solve construction problems and ensure the safety of the project. The project design team set up a scientific research team, combined with the actual situation to go deep into the construction site, through targeted theoretical analysis and numerical calculation, summarized the scientific disaster mechanism and prevention countermeasures, and proposed a series of anti-seismic, rock Explosion prevention and antifreeze damage and other technical measures. It has successively overcome technical problems such as high cold, high intensity, and high ground stress. Innovatively proposed a rockburst prediction method combining rock mass structure analysis and electromagnetic radiation monitoring, established a mechanical model of layered rock mass rockburst, improved the accuracy of rockburst prediction, and authorized a number of national invention patents. Innovatively proposed small-section super-long tunnel transportation system and transportation method, enriched the mechanized supporting construction technology of super-long single-track railway tunnels, combined with the rational design of auxiliary passages and excavation sections, greatly improved the construction speed.

The results of the project helped the completion of the Kamchik Tunnel 100 days ahead of schedule, saving about 160 million yuan in costs. The project has successively won honors such as the 2016-2017 China Construction Industry Association China Construction Engineering Luban Award, and the 16th China Civil Engineering Zhan Tianyou Award in 2018. Today, the technological achievements of the project have also been promoted and applied to projects such as the Bukamu Tunnel and the Milin Tunnel on the Lalin Railway.

The Kamchik Tunnel Project, the first longest tunnel in Central Asia, has demonstrated the professional brand image of China Railway Liuyuan Tunnel to the inside and outside of the industry. Contribute to the prosperity and glory of the road.Editor/Ma Xue