On September 17, it was learned that the large-diameter shield tunneling machine "Kunpeng," jointly developed by China Railway 11th Bureau Group and CRCC Heavy Industry, successfully rolled off the production line in Changsha. It will serve on the Shenzhen-Jiangmen High-Speed Railway (Shenzhen to Jiangmen) Shenzhen-Dongguan Tunnel, embarking on a journey of contributing to the Greater Bay Area.

The Shenzhen-Dongguan Tunnel (west section) has a total length of 15.3 kilometers and is a controlling project of the Shenzhen-Jiangmen High-Speed Railway. Among it, the shield tunnel of Section SJSG-7, constructed by China Railway 11th Bureau Group, is 3.84 kilometers long and features a large excavation diameter for the section, shallow cover at shield launching, and many types of risk sources to be crossed. In response to the geological and soil conditions of the area, the construction party customized for it the earth pressure shield tunneling machine "Kunpeng" with a maximum excavation diameter of 13.24 meters. This shield machine is currently the largest-diameter earth pressure balance shield machine used in composite stratum tunnel construction in China.

According to reports, during the preliminary selection work, the construction team successively invited several academicians of the Chinese Academy of Engineering and national survey and design masters to diagnose and advise, and after more than 20 rounds of design coordination, the production plan was finally determined. In response to the uneven soft and hard composite strata, "Kunpeng" adopts a thickened center cutterhead and an added visualization design for the soil chamber, and innovatively applies adjustable zoned combined hydraulic cylinders, which can effectively control the tunneling attitude. To cope with the tunneling challenges of "long distance, large burial depth, and high water pressure," the screw conveyor of "Kunpeng" adopts a sealed transverse-moving belt, and the cylinder wall adopts a detachable design, greatly improving the replacement efficiency of key equipment and the operating performance under high water pressure.

"Kunpeng" symbolizes strength and boldness. Production began on March 1 this year and was successfully completed in 198 days.

The Shenzhen-Jiangmen Railway is located in the center of the Greater Bay Area and is an important part of the coastal corridor of the national "eight vertical and eight horizontal" high-speed railway network. After the project is completed, it will comprehensively enhance the vitality of Dongguan and Shenzhen and become a strong support for further strengthening the construction of the Guangdong-Hong Kong-Macao Greater Bay Area and the Guangdong Pilot Free Trade Zone.