At 13:30 on August 23, as the cutterhead of the shield machine rotated slowly, the "Jinguan No. 18" shield machine broke through the soil on the left line of the Baimiao Station–Beiyangqiao Station section of Civil Works Package 6 of the northern section of Tianjin Metro Line 4, marking the smooth completion of the left-line tunnel of the Baimiao Station–Beiyangqiao Station section constructed by China Railway Beijing Engineering Group. With this, all four shield tunnels in the package have been completed.

The left line of the Baimiao Station–Beiyangqiao Station section has a total length of 836.713 meters. The project passes beneath structures including Wenjin Garden Park and the North Canal. The alignment features small curves, long distances, and shallow cover, and the section mainly traverses water-rich silty soft-soil strata, posing a great risk of water and sand ingress during shield launching and reception. At the same time, difficulties such as the shield cutterhead cutting and grinding through pile groups are encountered, making construction highly challenging, with high safety risks and many uncontrollable factors. To ensure safe reception, the project department organized meticulously, carried out scientific construction, strictly controlled key operation stages, strictly implemented the 24-hour leadership duty system, and strengthened reception safety and emergency management to ensure safe shield reception.

It is reported that the northern section of Tianjin Metro Line 4 is a trunk line in Tianjin's rail transit network serving the city's main center toward the northwest. Once the Tianjin Metro Line 4 is completed and opened to traffic, it will be of great significance for alleviating traffic pressure in Tianjin, driving urban economic development and the rational allocation of resources, and improving people's well-being.