On December 16, the ultra-large diameter shield machine "Yuanmeng", jointly developed by China Railway 14th Bureau Group and China Railway Construction Heavy Industry Group, was successfully rolled off the assembly line in Changsha. The Modern Express reporter learned that the shield machine will be used in the construction of the Suzhou East Tunnel of the Tongsu-Jiayong High-speed Railway, the "first tunnel of China's urban high-speed railway".
Tongsu-Jiayong high-speed railway is an important part of the national "eight vertical and eight horizontal" high-speed railway network coastal corridor, from Yancheng to Nantong high-speed railway Nantong West Station, southward through Suzhou City, Jiangsu Province, Jiaxing City, Ningbo City, Zhejiang Province, the introduction of Ningbo hub Ningbo Station, the line length of 301 kilometers, the design speed of 350 kilometers per hour. Among them, the Suzhou East Tunnel, located in Suzhou Industrial Park and Wuzhong District, has a total length of 15.57 kilometers, which is the high-speed rail urban tunnel with the highest construction standard and the longest mileage of 350 kilometers per hour in mainland China.
The tunnel section constructed by the 14th Bureau of China Railway is 13.03 kilometers long, including 11.82 kilometers of shield section, designed as a single-hole double-line shield tunnel, passing through 3 railways, 2 subway lines, 4 rivers and lakes and 20 roads and other complex urban environments, and the construction should pass through soft soil, high water pressure, high permeability sandy strata for a long distance, with a maximum buried depth of 58 meters, which has high requirements for the overall tightness and reliability of the shield equipment.
In this regard, China Railway 14th Bureau used the technical achievements and successful experience accumulated over the years to build a new slurry balance shield machine called "Yuanmeng", with a total length of 134 meters, a total weight of 4,200 tons, a total installed power of 10,000 kilowatts, and an excavation diameter of 14.81 meters, which is equivalent to the height of an ordinary residential building four or five floors.
According to the Tongyong High-speed Railway Project Department of China Railway 14th Bureau, the complete set of advanced technology of "push-spelling synchronization + synchronous double-liquid grouting + integral fully prefabricated box culvert synchronous assembly" carried by the "Yuanmeng" shield machine at the same time is the first application in the domestic super-large diameter shield equipment, which will comprehensively improve the safety of shield construction, construction efficiency and the quality of forming tunnels. Among them, the new technology of "super-large diameter shield pushing and assembling synchronization" independently developed by China Railway 14th Bureau can realize the simultaneous assembly of shield propulsion and segment assembly, and the construction efficiency will be increased by 30% to 40% compared with the construction process of "propulsion, stop and assembly" of traditional shield.
It is worth mentioning that the naming and appearance design of the "Yuanmeng" shield machine combine the regional characteristics of Suzhou. The name "Garden Dream" means that Suzhou, the "city of gardens", relies on large shield technology to open up the underground high-speed railway network and realize the dream of high-quality development, and the cutterhead of the shield machine is creatively coated with hairy crabs wielding double pincers, which means that the shield machine can quickly adapt to the developed geological environment of the water system and excavate efficiently.
Photo courtesy of the Tongyong High-speed Rail Project Department of China Railway 14th Bureau
(Proofread by Zhang Jingchao)