On May 22, as the shield machine cutterhead slowly rotated, the left-line tunnel of the Bolonghu Station–Chunhua Road Station section of Section 05 of Tianjin Rail Transit Line Z2 was successfully completed.

The left-line tunnel of the Bo–Chun section is the longest shield-driven tunnel section undertaken by the company, with a total length of 2,521.617 m. It was officially launched from the small-mileage end of Bolonghu Station on January 10, 2023, passing beneath Gangcheng Avenue, the West District Landscape Drainage River, the Jigang Railway, and Zhongxinzhuan Road, with a minimum curve radius of 500 m and a maximum gradient of 14.13‰. After 496 days and nights of arduous effort, 1,682 rings were completed, and reception was finally achieved at the large-mileage end of Chunhua Road Station on Beida Street.

To ensure the smooth reception of the section, the project department, through advance planning and meticulous organization, strictly controlled all tunneling parameters in accordance with the construction plan, ensuring that the shield machine passed smoothly beneath major risk sources such as the West District Landscape Drainage River and the Jigang Railway. During construction, the project team strictly controlled the accuracy of connection surveys, gyroscopic orientation surveys, and in-tunnel control surveys, solving the problem of difficult-to-control tunneling accuracy in long-distance tunnels and ensuring that shield tunneling construction was safe, stable, orderly, and controllable.