According to Xinhua News Agency, Kunming, December 3 (Reporters Wang Changshan and Ding Yiquan) The China-Laos Railway is an international railway directly connected to the Chinese railway network. The northern part of Laos finally reached Vientiane.
The total length of this railway is 1,035 kilometers, of which the section from Kunming to Yuxi is 106 kilometers long. It was completed and opened to traffic in December 2016.
The newly built section from Yuxi to Mohan is 507 kilometers long, and is an electrified railway with a design speed of 160 kilometers per hour and a dual-line single line; the newly built section from Moding to Vientiane is 422 kilometers long and is a single-track electrified railway with a design speed of 160 kilometers per hour.
During the construction of the new Yumo section and Mowan section of the railway, the Chinese and Laos builders overcame various difficulties and promoted the construction of the project with high quality and high efficiency. 167 tunnels were penetrated, 301 bridges were built, and the total length of the new tunnels and bridges was 712 kilometers.
Residents along the line said vividly that the China-Laos Railway is either in the sky (bridge) or in the cave (tunnel), and can only be seen at the station.
The scale and difficulty of construction of multiple tunnels are rare in the construction of domestic railway tunnels
At 17.5 kilometers, it is the length of the Anding Tunnel, the longest tunnel on the entire China-Laos Railway.
This tunnel was jointly constructed by the China Railway No. 5 Bureau and China Railway 19th Bureau. It traverses 20 faults and 2 syncline structures. The project scale, construction difficulty, and project risk are extremely rare in the construction of domestic railway tunnels.
Li Fei, chief engineer of the Yumo Railway Project Department of China Railway 19th Bureau, who was responsible for the construction of the export side, recalled the dangerous situation of the construction at that time, and his memory is still fresh.
"With a bang, thousands of square meters of earth and rock collapsed. The tunnel behind the three workers who were boring at the time was filled. Finally, they climbed out along a small gap in the roof of the cave." This happened at the end of 2018. The danger.
The 1.3 kilometers of stratum in the export section are mainly carbonaceous mudstone and shale, which are difficult to form, and become muddy porridge in case of water.
"The surrounding rock has been seriously altered. It was only more than 10 meters in a month at that time." Li Fei said.
Mud bursting and water gushing are the difficulties that restrict the passage of the Anding Tunnel on schedule.
During the construction, the builders innovated craftsmanship, adopted double-layer support control, and adopted effective measures such as large pipe shed lock feet to overcome many difficulties.
In November 2020, the first long tunnel of the China-Laos Railway was finally completed.
There is also the Friendship Tunnel, a cross-border tunnel connecting China and Laos on the border between China and Laos, with a total length of 9.59 kilometers and was constructed by China Railway Second Bureau.
The entire tunnel has complex geology, with the fourth-level surrounding rock accounting for 75% and the fifth-level surrounding rock accounting for 25%. It is a first-level high-risk tunnel.
What makes the builders more troublesome is that the tunnel is in a rock salt erosion environment, with a local salt content of more than 80%.
"Rock salt becomes salt water when it meets with water, which is extremely corrosive to steel bars and affects later operation safety." said Luo Hengfu, manager of the Yumo Railway Project Department of China Railway Second Bureau.
Beginning in June 2016, the South Yunnan Railway Construction Headquarters of China Railway Kunming Bureau Group organized the China Railway Second Bureau, the Academy of Railway Sciences and other units to carry out technical research. After efforts, the concrete strength reached the index requirements, and the world problem of the highly corrosive rock salt was overcome.
In September 2020, the Friendship Tunnel opened safely.
A miracle in the valley: how the bridge piers of a 50-story building were built
The red steel truss beams are flying on the gray bridge piers. From a distance, the Yuanjiang Bridge of the China-Laos Railway, which spans the Yuanjiang River, looks particularly magnificent among the mountains.
The bridge is about 832 meters long, of which the highest pier No. 3 is 154 meters, which is equivalent to the height of 50 multistory buildings.
The construction of such a high pier poses extremely high challenges to the builders.
The pier body weighs over 120,000 tons, plus 21,000 tons of steel truss girder. When not passing a train, the bottom of the pier has to bear a weight of about 150,000 tons.
“There are many faults and landslides at the bottom of the bridge piers. The rock mass is broken and bears such a heavy weight. This is a huge challenge for the builders.” said Zhou Jiawu, chief engineer of the Yumo Railway Yuanjiang Double Line Extra Large Bridge Project of China Railway Fourth Bureau. According to the expert argumentation, the construction plan of two reinforced concrete hollow piers through the cross beam on the top of the pier and the horizontal "X"-shaped steel structure in the middle was finally determined. Under the premise of ensuring that the load-bearing capacity is up to standard, the weight of the bridge pier was effectively reduced.
"The Yuanjiang Bridge adopts the domestically pioneered process and construction method, which provides a Chinese solution for bridge construction with similar geological conditions." said Guo Huiming, director of the Construction Department of the China Railway Kunming Bureau Group.
The construction of the China-Laos railway is full of science and technology.
China Railway Wuhan Electrification Bureau is responsible for the construction of electrified railways from Kunming to Vientiane. It has set up intelligent construction workstations on the border between China and Laos. Relying on digital construction and intelligent construction "two-wheel" drive, it has created a new benchmark for the "four electricity" project of 160 kilometers per hour normal speed railway.
The real-time construction picture and measurement data are displayed on the screen of the dispatching command big data platform.
"In the past, data was collected by people and entered into computers, and the data was not connected. Now, based on Beidou positioning and infrared scanning technology, an integrated measurement device for catenary construction parameters has been developed, which integrates calculation and measurement and data sharing." China Railway Wuhan Electrification Bureau Yumo Said Zhou Zhiqiang, secretary of the Party Working Committee of the Project Department.
The professional construction technology team of China-Laos Railway has successively completed 15 scientific research results including the integration of catenary infrastructure in tropical rainforest areas, optimized design and technology 65, developed and applied 27 smart tools, 11 smart tooling, and realized the complete construction of China-Laos railway Process of "Digital Intelligence Construction".
In addition, intelligent equipment such as the tunnel integrated intelligent operation platform developed during the electrification construction of the China-Laos railway fills the domestic gap.
It used to take 2 hours for people to set up a 500-meter guide line, but now it can plan thousands of kilometers of track laying in 1 hour; it only took more than 80 days to create a track record of 500 kilometers... In the Yumo section, a 500-meter-long steel rail independently developed by China Under the guidance of the operation mode of "Automatic Cruise Tracking and Positioning System", the track laying machine can lay precisely.
Liu Shugong, the project manager of the Yumo Railway Construction Project Department of China Railway First Bureau, said that the comprehensive use of advanced positioning technologies such as Beidou, total station, and the Internet of Things will change the mode of setting guide lines in advance by human eyes.
In order to reduce the impact on the environment, the designer has studied more than 60 three major directions of east, middle and west.
When selecting the route for the China Section of the China-Laos Railway, the designers comprehensively compared and selected the route, long and short tunnels, bridges across the river, and station locations based on comprehensive geological conditions, environmentally sensitive points and other factors, and determined that they were economical, reasonable, environmentally friendly and feasible. The overall plan of the route.
According to the person in charge of the overall design of the China Section of the China-Laos Railway of the Second Institute of China Railway, he listened to the opinions of the environmental protection and water conservancy departments and the people along the line during the design, fully applied the results of the environmental impact assessment report, and avoided the core areas, buffer zones and Environmentally sensitive points, reduce the impact on the environment, study more than 60 three major directions of east, middle and west, and study the total length of more than 14,000 kilometers.
Regarding the protection of wild Asian elephants that are highly concerned by all walks of life, at the beginning of the design, all parties investigated the distribution of wild elephants and their migration channels, and analyzed the impact of construction on the activities of wild elephants and their migration corridors.
The route plan avoids the main activity areas of wild elephants, and the exposed section of the surface does not involve the existing migration channels of wild elephants. Measures such as extending the tunnel, adjusting the position of the inclined shaft of the tunnel, and replacing the road with bridges are adopted to minimize the impact.
Yexianggu Station is adjacent to the Asian Elephant Nature Reserve.
“The two ends of the station are passed through in tunnels, and the construction is underground, which reduces the impact on the ecological environment and does not affect the activities of the wild elephants after opening.” said Wang Junmin, the project leader of the Yumo Railway Yexianggu Station Project of China Railway Construction Group Corporation.
"The ride comfort and comfort of the China-Laos railway train is very good." said Wang Gengjie, chairman of China Railway Kunming Bureau Group Co., Ltd. The four new benchmarks for the electric innovation demonstration project, combined with the actual operation of the Fuxing EMU on the China-Laos railway, and the “four electric” high-quality projects with the spirit of craftsmanship based on the concept of “science and technology + innovation”, are the benchmark projects for the normal-speed railway with a speed of 160 kilometers per hour.
A new steel silk road that is as beautiful as the mountains and rivers will benefit the people along the route.