On November 22, as the "Qianjin No. 7" shield machine broke through the tunnel portal and slowly emerged, it marked the smooth breakthrough of the right line of the Dongjiayan Station-Zhongcaosi Station section, the longest shield tunnel section on Rail Transit Line 3, 24 days ahead of schedule.

The right-line tunnel of the Dongjiayan Station-Zhongcaosi Station section is 2,427 meters long and runs along Huaxi Avenue. The tunnel crown is buried at a depth of 4.8-1.5 meters. The tunnel mainly passes through moderately weathered dolomite and argillaceous dolomite strata. The section passes beneath 43 fracture zones in total and 19 risk sources. To ensure normal traffic on Huaxi Avenue, "Qianjin No. 7" adopted an unconventional launch scheme of "hoisting in from outside the station + translational movement inside the station." To "return the road to the public" as early as possible, the shield construction site was set up in the narrow gap between Huaxi Avenue and Dazhi Road, making the construction site extremely cramped.

Since the shield machine in this section was officially launched on November 9, 2020, in the face of many difficulties such as a tight schedule, heavy tasks, and high safety risks, the project department did not wait or rely on others, but took the initiative, faced difficulties head-on, and followed the method of "keeping the machine running while people rest, making full use of time, and fully utilizing space." It carried out uninterrupted 24-hour construction, continuously optimized the construction plan, and promoted construction production through scientific and technological innovation, ensuring the smooth and orderly progress of construction.