On September 12, the Nanjing Metro Line 11 project completed construction of the rectangular pipe jacking machine for Auxiliary Entrance 10, marking the breakthrough of Entrance 10 of Pukou Wanhuiting Station into the main station structure.

Pukou Wanhuiting Station of Nanjing Metro Line 11 is located on the south side of the intersection of Pubin Road and Pukou Avenue, and Auxiliary Entrance 10 is located on the east side of the station, with the entrance passage running across Pubin Road. Once completed, pedestrians will be able to use this passage from Kangping Road under Pubin Road to Pukou Wanhuiting Station to transfer to Line 10.

The Entrance 10 pedestrian underpass at Pukou Wanhuiting Station crosses the Pubin Road expressway, where traffic is heavy and the surrounding environment is complex, making open-cut construction infeasible. Therefore, the rectangular pipe jacking method was adopted, with a 5×7 m extra-large cross-section earth pressure balance pipe jacking machine advancing from Entrance 10 toward the station.

The pipe jacking passage lies in water-rich mucky silty clay with only 5.1 m of cover, and the geological and hydrological conditions are complex, making advancement difficult. Before launching, the project department anticipated the adverse geological and water level conditions and, by adding emergency dewatering, reinforcing the portal, and increasing the frequency of monitoring and measurement, combined with analysis and summary of monitoring data, maintained the stability of the excavated face soil through control of the front earth chamber pressure and muck discharge. It also continuously optimized construction parameters based on jacking thrust and monitoring data during advancement, promptly adjusting subsequent construction parameters and measures such as grouting and mud injection to further control deformation of the surrounding environment and ensure smooth pipe jacking advancement.

Since preparations for pipe jacking construction began, the Nanjing Metro Line 11 project team carried out scientific planning and meticulous deployment for early-stage site layout and equipment selection research and demonstration, and organized experts to demonstrate and improve the special safety construction plan for pipe jacking machine tunneling and the lifting operation plan for large equipment. At the same time, in response to thorny issues such as the high difficulty, high requirements, tight schedule, and heavy tasks of pipe jacking construction, technical briefings were conducted at all levels and work instructions were prepared.

By staffing fully with an experienced and highly execution-capable technical team and construction crews, the project team successfully overcame a series of unfavorable factors, including the lifting and transport of extra-large components, a narrow construction site, on-site cross operations, and a tight construction schedule. It promptly coordinated and resolved various problems arising at the construction site, ensuring that the disassembly, lifting-in, transfer, lowering into the shaft, assembly, and commissioning of the pipe jacking machine, as well as other supporting facilities, were efficiently completed within the established time, ultimately achieving smooth breakthrough and reception as planned.

After 26 days of continuous jacking, the project's rectangular pipe jacking machine construction was successfully completed, laying a solid foundation for the early completion of the project's auxiliary works and subsequent work, and fully demonstrating the company's new advantages in the field of trenchless technology for underground engineering. At present, the project has entered the full sprint stage, and the project department will maintain its momentum and uphold the determination to overcome difficulties and fight to win, ensuring high-quality project performance.