On October 13, Chongqing Rail Transit Line 7 achieved a major milestone as the left tunnel boring machine successfully reached the receiving end in the section between Logistics Park North Station and Logistics Park South Station. This marks the completion of dual-tunnel breakthrough for this section, making it the first segment of Chongqing Rail Transit Line 7 to achieve full dual-tunnel breakthrough, representing a new phase in the construction of this important urban rail transit line connecting key city areas.
The left tunnel of this section spans approximately 1,334 meters with tunnel depth ranging between 13.9 meters and 35.2 meters. The tunnel features a circular cross-section design with a maximum gradient of 20‰ and a minimum turning radius of only 450 meters.
To overcome construction challenges including continuous small-radius curve tunneling and passing beneath existing buildings, the project team established technical task forces to develop specialized construction plans. Using real-time tunnel boring machine guidance systems and monitoring systems, the team dynamically adjusted tunneling parameters, enhanced settlement monitoring, and optimized grouting processes and pressure control. These measures effectively mitigated construction risks, ensured precise tunnel alignment and segment assembly quality, and achieved zero interference with existing buildings, municipal roads, and underground pipelines along the route.
Upon completion, Rail Transit Line 7 will significantly improve Chongqing’s public transportation network, enhance travel conditions for residents along the route, and provide crucial transportation support for regional economic development. The project team stated that subsequent construction will continue with a focus on safety first and quality supremacy principles.