On the morning of October 10, at the construction site of Longxing Station on Phase II of Shenzhen Metro Line 16 undertaken by China Railway 14th Bureau Group, the cutterhead of the shield machine "Xing'an No. 1" slowly broke through the wall, marking the successful completion of the left line of the shield-driven section from Yuanshan Station to Longxing Station on this line.

▲Breakthrough of the left line of the Yuanshan Station–Longxing Station section

The left line of the Yuanshan Station–Longxing Station section of Phase II of Shenzhen Metro Line 16 has a total length of 1,060.8 meters. The line is located in Longgang District, Shenzhen, one of the areas with the most complex geological conditions in China. The section passes through complex and variable strata including soft soil, hard rock, upper-soft/lower-hard ground, and karst development, akin to tunneling through a "thousand-layer cake." At the same time, the section runs along a small-radius curve beneath a mountain segment, where factors such as large burial depth and high water pressure combine; it also passes beneath dense clusters of old buildings, with a dense network of pipelines under municipal trunk roads and poor stability of shallow building foundations, resulting in high construction risk.

To ensure smooth shield tunneling, the construction team actively coordinated with the survey and design units, proactively carried out targeted infill surveys, and effectively identified adverse geological conditions along the crossing section using cross-hole CT and ground-penetrating radar scanning, followed by reinforcement treatment. Meanwhile, the project department carefully assembled the shield construction team, reasonably selected the shield machine, and strictly controlled the shield attitude and segment selection to ensure the quality of the completed tunnel in the curved section and achieve high and stable output.

▲Completed tunnel

In response to the key and difficult control issues during tunneling, the project formulated emergency plans and linkage mechanisms, strictly controlled tunneling parameters and muck discharge, carried out settlement monitoring, and, combined with HSP advanced geological prediction and ground-penetrating radar detection, successfully achieved a "zero-settlement" crossing through a combination of pre-grouting and follow-up grouting.

As a key project of rail transit in the Guangdong-Hong Kong-Macao Greater Bay Area, Phase II of Shenzhen Metro Line 16 is a trunk rail line for southward expansion from Universiade New Town in Longgang Central City. Once completed, it will continuously optimize the "metro + high-speed rail" transportation network, accelerate the flow and efficient allocation of resources in the Bay Area, and promote the integrated, high-quality development of the Bay Area.