On May 30, the "Kunpeng" (Shenjiang No. 3), the largest-diameter earth pressure balance shield machine for domestic mixed-ground tunnels, jointly built by CRCHI and China Railway 11th Bureau Group and applied to the construction of Section SJSG-7 of the Shenzhen-Jiangmen Railway project, was successfully launched.

Section SJSG-7 of the Shenzhen-Jiangmen Railway project is one of the controlling and most difficult works of the Shenzhen-Jiangmen Railway. The tunnel is 3.84 km long with a maximum burial depth of 62 m, and is a large-diameter single-tube double-track railway tunnel. The section mainly passes through moderately weathered, strongly weathered, strongly weathered granitic soil and completely weathered granite, and locally passes through silt and silty clay. It needs to pass beneath multiple risk sources such as rivers, highways and bridges, and is characterized by a large excavation cross-section, great burial depth and complex geological conditions, posing huge challenges to safe construction.

To meet the construction requirements under the complex geological conditions of the project, CRCHI, drawing on its rich design and application experience, tailor-made the "Kunpeng" shield machine. The machine has an excavation diameter of 13.24 m, a total installed power of 9,300 kW and a total weight of about 3,400 t, and is the largest-diameter earth pressure balance shield machine for domestic mixed-ground tunnels independently developed by CRCHI. The "Kunpeng" shield machine is not only equipped with innovative technologies such as a telescopic main drive, simultaneous single- and double-fluid grouting and air-pressure-assisted excavation, but also carries multiple advanced functions such as synchronous assembly of integral large box culverts and fine adjustment of box culverts, enabling it to effectively handle various complex geological conditions such as uneven hardness and softness, and providing strong support for the smooth construction of the Shenzhen-Jiangmen Railway project.

The Shenzhen-Jiangmen Railway is located in the center of the Greater Bay Area. It is not only an important part of the coastal corridor of China's "Eight Vertical and Eight Horizontal" high-speed railway network, but also a major cross-river intercity corridor in the Pearl River Delta region. Once completed, the project will realize half-hour high-speed rail interconnection within the living circle and economic circle of the Guangdong-Hong Kong-Macao Greater Bay Area, and become a strong support for further strengthening the integrated development of the Greater Bay Area and the construction of the Guangdong Pilot Free Trade Zone.