[business card]
"Jinghua" shield machine, with a diameter of 16.07 meters, a length of 150 meters and a weight of 4,300 tons. Lying horizontally, it is even higher than five stories … It looks heavy, but it has high skills: it is a good hand at digging holes and a sharp weapon for tunnel construction, like an underground dragon, such as a "steel pangolin". The shield machine developed by Tiejian Heavy Industry, from running to leading technically, has become another "Made in China" business card after "China High Speed Rail".
Hunan Daily All-Media Reporter Cao Xian Correspondent Hu Qing
In Tongzhou District, Beijing, the west tunnel of the East Sixth Ring Road reconstruction project is under construction. On the ground, beijing-harbin railway got on the high-speed train and galloped by, but the passengers didn’t notice that a "steel behemoth" was steadily driving tens of meters underground.
On April 12, 2022, China’s largest diameter shield machine "Jinghua" successfully crossed the Jingha high-speed railway line. This behemoth plunges underground, causing no disturbance to the ground buildings, and controlling the surface settlement in millimeter level, creating a miracle of the construction of super-large diameter shield machines in China.
This "Jinghua" shield machine rolled off the production line in Changsha No.1 Industrial Park of China Railway Construction Heavy Industry Group Co., Ltd. on September 27th, 2020. Shield machine is known as "the king of construction machinery". China was once a zero foundation, and its technology and market were controlled by people. Nowadays, the domestic brand shield machine represented by China Railway Construction Heavy Industry has occupied two-thirds of the global market share.
Over the past 10 years, how did China shield machine strike back brilliantly?
1 "2 mm" see skill-
Buried in stealth, amazing years
Shield tunneling relies on many cutter heads embedded in the front circular cutter head. The cutter head rotates slowly, like a big mouth, and the cutter head is like a tooth, which "chews up" rocks and sand and transports them through the pipeline.
Shield construction is to dig tunnels under the ground, and there is no need to "open the belly" on the ground, which has little impact on road traffic. In the underground reconstruction part of Beijing East Sixth Ring Road Reconstruction Project, the tunnel shield construction section is about 7.4 kilometers long, and the excavation section size is six times that of the general subway tunnel.
"It is the first time in the world for a shield machine with such a large diameter to dig such a long distance at a time." Railway Construction Heavy Industry undertook the task of developing "Jinghua", and the R&D team faced unprecedented challenges.
The underground space environment is complex, and more than 50 risk sources are densely distributed on the ground. Super-large diameter, super-long distance, super-deep soil cover and super-sensitive environment, some authoritative people in the industry are worried: "Will domestic equipment work?"
Without two brushes, I can’t do it.
In the process of tunneling, the shield machine faces all kinds of interference caused by earth pressure, underground water pressure, mud in and out, and rocks in the way. The R&D team adopted a high-precision gas-liquid balance control technology, and an air cushion cabin was set behind the cutter head cabin, so that the pressure was indirectly transmitted instead of directly impacted. Figuratively speaking, it is the increase of pressure and exhaust; Sudden pressure drop, replenishing qi, and instantly eliminating pressure fluctuation.
"The underground’ movement’ is big, and what to do on the ground is not affected." Zhang Shuaikun, vice president of Railway Construction Heavy Industry Roadheader Research and Design Institute, said that during the excavation of Jinghua, the surface settlement was always controlled within 2 mm.
By June 1, the "Jinghua" had broken through 3,668 meters, and the excavation was more than half successful. In the meantime, a new record of 542 meters in a single month was created. "Whether it is size or technology application,’ Jinghua’ has reached the world’s leading level." Zhang Shuaikun said proudly.
On the network platform, the short video about "shield machine" has been viewed by millions of people. While enjoying the convenience of cars and subways passing through tunnels, people want to know why tunnels are dug quickly and well now.
In the 1950s, China put forward the plan to build a subway in Beijing first. The first phase of the 23.6-kilometer-long Beijing subway project took more than 10 years from construction to trial operation.
Before tunnel construction in our country, the traditional manual drilling and blasting method was used to drill, shoot and dig stone slag, which cost a lot of manpower, material resources and even life. "Compared with the current shield machine that digs hundreds of meters every month, at that time, it was greedy every day, and it could not dig dozens of meters in one month." He Qiping, the 58-year-old chief technology officer of China Railway Construction Heavy Industry, has worked as a tunnel for most of his life and experienced great changes in the industry. He said with deep feeling that it would take at least 100 years to build all subway lines in China at the same speed as that of Beijing Line 1. Because China has its own shield machine, the speed of subway construction has been accelerated for more than 60 years.
Compared with the predecessors in the industry, Zhang Shuaikun, born in 1980s, is lucky. His WeChat avatar is "Jinghua", and the blank space of the photo reads: Burying your head and sneaking, amazing years. These eight words have become the best annotation of the largest diameter shield machine made in China, and also a vivid portrayal of countless hard-working scientific researchers and industrial workers.
2 From "1" to "1000+"-
The "printing machine" of foreigners has become the "competitive machine" of China people.
Seen from the satellite perspective, the super factory of Tiejian Heavy Industry in Changsha, Hunan Province is a shining new industrial landmark.
Ten years before the birth of "Jinghua", Railway Construction Heavy Industry produced the first EPB shield machine named "Pioneer 19".
"Pioneer" broke the game in one fell swoop. "Let the’ foreign shield’ with an average selling price of about 150 million yuan quickly reduce its price by 30% in China." Liu Feixiang, Party Secretary and Chairman of Tiejian Heavy Industry, said.
In the 1990s, China imported shield machines from abroad for the construction of large-scale tunnel projects. Wu Min, vice president of Railway Construction Heavy Industry Roadheader Research and Design Institute, used to drive foreign equipment in tunnel construction units, and he often wondered "when can the domestic shield machine be used".
Foreign shield machines are expensive to sell and the service is more expensive. Foreign companies hold key technologies in their hands, charge high service fees, wait until working days to solve problems, and often refuse to accept the rectification and optimization suggestions of domestic contractors.
The rapid development of China is changing with each passing day. The high-speed rail and subway network are accessible, and water conservancy and mine construction are speeding up. Large-scale engineering equipment like shield machine is too important.
You can’t always be led by foreigners. In 2008, Tiejian Heavy Industry decided to specialize in customized underground engineering equipment.
Supported by the "863" project of the Ministry of Science and Technology, in 2012, China Railway Construction Heavy Industry launched an attack on the first domestic rock tunnel boring machine (TBM). Different from the shield machine that eats soft rock and gravel, the rock tunnel boring machine takes hard rock as the "next meal", which is also the weak link of the autonomy and localization of tunnel boring equipment in China.
Knowing this news, Wu Min gave up his job with higher income at that time and devoted himself to the development of the first domestic TBM.
From scratch, grope forward. For twenty or thirty big parts such as cutterhead, shield, main beam support and propulsion, a research team is set up for each part. Every data is accounted for over and over again, and it is pushed over and over again. More than 3,000 mechanical drawings have been audited.
At the end of 2014, the first domestic open TBM was rolled off the assembly line of China Railway Construction Heavy Industry. In participating in the construction of water supply project of Jilin Province, the highest monthly footage of this TBM reached 1,209.8 meters, and the bid was completed more than one year ahead of schedule, leaving the foreign brands that competed in the same field and ranked first in the world at that time far behind. "Very uplifting!" Wu Min is quite proud of this product.
Today, there are 40 shield machine production lines in Changsha No.1 and No.2 Industrial Parks of Railway Construction Heavy Industry, which has become the largest underground engineering equipment manufacturing base in the world. Over the past 10 years, more than 1,000 roadheader machines have been sent from here. The shield machine, once regarded as a "printing machine" by foreigners, has now become a "competitive machine" for China people.
Great country heavy weapon serves great country project. The western water conservancy project, with a maximum buried depth of 2268 meters, is all over the altered rock belt. The variable diameter open TBM solves the "stuck machine" problem that plagues the world excavation industry and successfully breaks through the barrier. In the Pearl River Mouth Tunnel of Shenjiang Railway, "Shenjiang No.1" advanced to the depth of 106 meters, helping to build a half-hour living circle in Guangdong-Hong Kong-Macao Greater Bay Area …
3 From "Apprentice" to "Teacher"-
China equipment accelerates the equipment world.
In the early summer, on the west bank of Xiangjiang River in Changsha City, the super-large diameter shield machine "Xingsheng" is being debugged, and the trip across Xiangjiang River will be started soon, which will help alleviate the traffic bottleneck in the central city of Changsha.
From Beijing to Changsha, Railway Construction Heavy Industry has developed 6 sets of shield machines with super-large diameter of 15 meters and above. The core technology of shield machine in China has become more and more mature and powerful.
Shield machine integrates advanced technology in many fields, such as machinery, electricity, liquid, light, control, engineering, etc. Its manufacturing process is complex, and its degree of autonomy directly reflects the industrial level and industrial chain perfection of a country.
Size, there are "super" and "tiny". A shield machine with a diameter of only 0.5 meters, "the sparrow is small and complete."
Technology, from running to part leading. Horizontal excavation, vertical shaft, inclined shaft, various modes and special-shaped sections are not a problem.
Market share from supporting role to leading role. The output of rock tunnel boring machine of China Railway Construction Heavy Industry has been the first in China for five consecutive years. The domestic brand shield machine represented by China Railway Construction Heavy Industry has climbed to more than 95% in the domestic market share, accounting for two-thirds of the global market share.
People have no me, people have my advantages, and China roadheader strode out of the country.
In 1950s, Soviet experts came to China to help Beijing plan the first subway line. Sixty years later, five shield machines from China Railway Construction Heavy Industry participated in the construction of the southwest section of the third interchange ring road of Moscow Metro, and were affectionately called "five golden flowers" by the locals.
The "Five Golden Flowers" proudly bloomed in snow, which overcame the extremely cold environment of minus 30 degrees Celsius, set a new record for local subway construction and became a model for overseas construction of shield machines in China.
On the eve of the Spring Festival in 2022, after more than seven hours of overseas connection, Railway Construction Heavy Industry finalized cooperation with an Italian construction company. China shield machine is about to enter the Italian market for the first time.
"Hundreds of technical parameters are compared one by one, and the attitude of the other party gradually changes from distrust to trust." Zhong Qing, an engineer from the Research and Design Institute of Railway Construction Heavy Industry Roadheader, said that China shield machine has comprehensive advantages in terms of price, performance, quality and service, and is more competitive than foreign brands. He said with emotion, "I used to be a teacher, but now I am a teacher." In less than 20 years, the change is too great. "
The reporter walked into the assembly workshop of Railway Construction Heavy Industry, but saw a shield machine being hoisted and tested in an orderly manner. The base label showed that the destination was Sri Lanka, India and Singapore. In the first quarter of this year, the amount of new overseas contracts signed by Railway Construction Heavy Industry increased by 9 times year-on-year.
Along the "Belt and Road", China equipment accelerates the equipment world. In 2021, Tiejian Heavy Industry ranked among the top 30 global construction machinery manufacturers and ranked first among the top 5 global full-face tunnel boring machine manufacturers.
[Youth Watch]
Move the classroom into the workshop
I have a "billion-point" heart.
Deng Kangwei (a junior majoring in urban underground space engineering in Central South University)
It is accidental to choose the major of urban underground space engineering. On the weekend of my freshman year, I read several books related to urban underground space in the library and learned that the use of above-ground space is becoming increasingly saturated, and underground space will become the "main battlefield" for urban construction. So, when I subdivided my major, I chose this major.
This semester’s professional courses often talk about shield machines. As a young observer of Hunan Daily, I came to Tiejian Heavy Industry to observe the shield machine at close range. For me, it is like moving the classroom into the workshop and learning the principle and structure of the shield machine in front of books and drawings in class. It is a completely different experience.
It took me six hours to assemble the toy of shield machine building blocks presented by the enterprise, so I can experience the fun of "manufacturing" a shield machine. In fact, there are more than 30,000 large and small parts on a shield machine. From conventional diameter to the development of super-large diameter shield machine, technicians have devoted themselves to tackling more than 2900 days and nights.
I was deeply impressed by this statement that the shield machine has changed from a "printing machine" for foreigners to a "competitive machine" for China people. Scientific researchers have gnawed at the "hard bones" of core technologies, and industrial workers have developed the hard skills of striving for perfection, so that China’s independent research and development of shield machines is no longer subject to people, from zero foundation to mastering key core technologies, leading the world.
Walking into the super factory of shield machine, I saw the big scene of shield construction and became a "shield driver" as I wished. This "immersive experience class" made me feel the innovative power of hard-core technology, which made me feel "a little bit" and made a different plan for the future.
Urban underground space contains unlimited development space, and the future awaits us to change and create with broader knowledge and broader horizons.