At 8:16 on November 25, at the construction site of Baishitang Station on Phase IV of Shenzhen Metro Line 3, as the shield cutterhead slowly rotated, the 6.44-meter-diameter 'Dongjin No. 8' shield machine successfully completed its launch. This section adopted a steel sleeve for launching. Following the successful breakthrough of the right line from Low Carbon Station to Pingxi Station on Shenzhen Metro Line 3, another 'Iron Army' tunneling team from China Railway Sunward is helping to build the Greater Bay Area.

The Shenzhen Metro Line 3 extension project undertaken by China Railway Sunward includes a total of 2 sections. Among them, the section from Low Carbon City Station to Baishitang Station is a double-track tunnel, with the left line 1,168.50 meters long and the right line 1,148 meters long, and a maximum burial depth of 17.4 meters. The 'Dongjin No. 8' shield machine launched from Baishitang Station. The section needs to pass beneath a karst development area, Pingxi Bridge, Pingxi Small Bridge (box culvert), buildings and factory buildings, upper-soft and lower-hard strata, and a river, before finally reaching Low Carbon City Station in Shenzhen International Low Carbon City, the 'Pilot Demonstration Zone for Carbon Peaking and Carbon Neutrality'.

During this tunneling process, the 'Dongjin No. 8' shield machine mainly passes through strata of gravel, silty clay, karst caves, strongly weathered granite, and slightly weathered marble. There are a large number of karst caves in the marble layer of the section, and the surrounding environment is complex, resulting in relatively high construction risks. In response to construction difficulties such as dense karst development in this project, before launch, the project department carried out advance grouting reinforcement, geological radar scanning, and other operations in advance. At the same time, it optimized the design of the shield machine. The shield construction adopted advanced technologies such as soil chamber visualization, automatic measurement of shield tail clearance, automatic measurement of muck, and tunnel air-conditioning ventilation and cooling, and conducted real-time follow-up measurement of the shield machine's excavation position to ensure smooth tunneling by the shield machine.

This section is among the first sections in Shenzhen Metro to adopt steel sleeve launching, that is, using steel sleeve launching technology to replace the traditional end reinforcement process. This not only ensures the safety of shield construction, but also greatly saves consumption of construction materials, reduces construction costs, and practices the concepts of green, energy-saving, and low-carbon development. Before the shield launch, the project department successively invited experts to demonstrate the construction plan, conduct drawing review, review the shield machine configuration, and provide consultation on optimization of the construction plan, ensuring the smooth completion of the shield launch.

This shield launch marks that the section from Low Carbon City Station to Baishitang Station of the Shenzhen Metro Line 3 project undertaken by China Railway Sunward has officially entered the tunnel shield construction stage. After the completion of Shenzhen Metro Line 3, it will greatly enhance Shenzhen's urban rail transit operation capacity, further raise the economic development level of eastern Longgang, and strengthen connections among major groups in the east.

Sunward Intelligent Official Website