10/20/2022 13:13 Last update: 13:18
Recently, the construction of the Shenzhen-Jiangmen high-speed railway has officially started, which includes the deepest submarine tunnel in the country, and the construction difficulty is quite rare.
Shenzhen-Jiangmen high-speed railway. Picture of “China Railway”
As an important infrastructure in the Guangdong-Hong Kong-Macao Greater Bay Area, the Shenjiang high-speed railway line starts from the newly built Shenzhen Xili Station, goes west through Dongguan City, Guangzhou City, Zhongshan City, Jiangmen City, and connects to Jiangmen Station Jiangmen-Zhanjiang Railway The full length of the main line is 116 kilometers, the construction period is 5.5 years, and the bridge-tunnel ratio of the whole line is 98%.
Great powers help great projects. Picture of “China Railway”
Because the line needs to cross the Shiziyang sea area in the Pearl River Estuary, and the geographical environment is very complex, the designers have finally decided to pass through the Pearl River Estuary in the form of a tunnel after comparison and selection plans for several years. The tunnel has a total length of 13.69 kilometers. It is a management project for the entire line and the deepest submarine tunnel in my country. The maximum underwater depth is 115 meters, and the maximum water pressure is 1.06 MPa. It can travel through dozens of complex layers over long distances.
Schematic diagram of the tunneling direction of the shield machine on the seabed. Picture of “China Railway”
How to build a submarine tunnel 100 meters deep? This requires two customized “superpower tools”, the domestic shield machines “Shenjiang No. 1” and “Shenjiang No. 2”, they can drill rocks and break walls like giant pangolins.
With a total length of 133 meters and a total weight of around 3,900 tons, the shield machine is definitely a behemoth. So heavy, it should be sturdy, right? Actually, it’s not. The inside of the shield machine is deep and open, with many detailed circuits distributed. Walking into it is like being in a mechanical castle.
Schematic diagram of shield machine structure. Picture of “China Railway”
The structure of the shield machine is a bit like a train, which consists of a cutter head, a shield body, and an auxiliary trailer. The cutter head is the “hole punching tool” at the front end of the shield machine, and it is embedded with a large number of knives of various shapes. The shield is the main part, which supports the digging of the tunnel and protects the internal components of the shield. “Shenjiang No. 2” has a total of 5 sections, the running mechanism is at the front, and the rear part is attached.
“Shenjiang No. 1” is painted in the shape of a lion. Picture of “China Railway”
Interestingly, these two shield machines are not only powerful tools for advanced engineering, but also have a stylish appearance.
“Shenjiang No. 2” is painted in the form of a dragon. Picture of “China Railway”
“Shenjiang No. 1” is painted in the form of a lion, and “Shenjiang No. 2” is painted in the form of a dragon, which highlights the cultural characteristics of Guangdong and has provoked heated discussions among netizens as early as when there is put it into use.
How do such huge “awakened lions” and “dragons” work?
“Post-95” Yang Chen is the first female shield machine driver in the country. She is very proud of being able to operate the sophisticated heavy equipment of a large country to gallop on the seabed at a depth of 100 metres.
The requirements for dynamic control in the shield tunneling process are extremely challenging. Picture of “China Railway”
He submitted that due to the uneven hardness and softness of the soil, the shield machine tends to deviate when digging, and at this time, it is necessary to adjust the direction by hand. In addition, the shield machine must be correctly connected after long-distance mining, just like threading a needle in the sea, and the dynamic control requirements of the shield machine during the mining process are extremely difficult.
In a 15-square cab, there are more than 200 buttons, 9 screens, and various types of intercoms, and the flashing indicator lights are dizzying. The entire operating platform is divided into a drive system and a circulation system.
The shield machine looks huge, but it moves slowly, only a few centimeters per minute. Most of the shield tunneling machines are currently in service at an average of about 5 to 10 meters per day, and “Shenjiang No. 2” set a good result of 24 meters per day and a monthly record of 342 meters.
Pearl Estuary Tunnel. Picture of “China Railway”
At present, “Shenjiang No. 2” has been excavated for 1,200 meters, which is one step closer to the completion of the Pearl River Estuary Tunnel, laying a solid foundation for the construction of the Shenjiang high-speed railway, and also showing the “counterattack” the domestic shield machine.
More than a decade ago, domestic shield construction basically relied on imported equipment, and the “sky-high” shield machine, which cost hundreds of millions of yuan, had to be shut down when it broke down, waiting for foreign engineers to repair it. Because the foreign party monopolizes the technology, the Chinese party is not allowed to participate in the maintenance, and the required man hours are also completely dependent on the foreign party, which seriously affects on the progress of the project.
In April 2008, my country developed the first composite ground pressure equalization shield machine with independent intellectual property rights, which achieved breakthrough from the beginning, and continued to innovate independently in the following years. China’s largest diameter earth pressure balance shield machine, China’s largest diameter hard rock shield machine, and China’s largest diameter mud-water balance shield machine have come out one after another, and the independently developed shield machine has moved from “existing” to “excellent”.
Today, the shield machinery made in China has excellent technology, high quality and low price, gradually surpassing Europe and the United States, occupying most of the world’s shield machinery market, and finally achieving counterattack.
hair clip
**Blog articles are at your own risk and do not represent the position of the company**
see more articles below
