The NPT3700 slurry balance shield machine supplied by Yangzhou Dilong has successfully completed tunneling works for the Wuxi Hynix Phase II-Yingyue 220kV Transmission Line Cable Civil Engineering Project. As the first shield equipment deployed for power engineering projects in Wuxi, the machine maintained stable operation and controllable, efficient tunneling throughout the construction. It finished the tunnel section to high standards and set a new benchmark for mechanized and intelligent construction of regional power tunnels.

The Wuxi Hynix Phase II-Yingyue 220kV Transmission Line Cable Civil Engineering Project is a key local supporting power infrastructure. The shield-driven section stretches 530 meters in total, with the tunnel crown buried at a depth of approximately 12 to 13 meters and a minimum turning radius of 500 meters along the alignment. Power tunnel projects impose strict requirements on construction precision, surface settlement control and operational safety. Urban power tunnel construction also demands rigorous schedule management and stable excavation performance. Conventional open-cut construction brings substantial ground disturbance, low efficiency and insufficient safety risks. Mechanized shield tunneling can effectively avoid these drawbacks and ensure safe, high-quality and efficient project delivery. Being the first shield machine adopted in Wuxi’s power engineering sector, this project also serves as an important demonstration for promoting new construction technologies for regional power tunnels.

The project utilized the self-developed and self-manufactured NPT3700 slurry balance shield machine for all tunneling operations. Optimized for urban power tunnel working conditions, the equipment suits medium-and-short-distance, deep-buried and small-curve tunnel construction scenarios. Equipped with a high-precision slurry balance control system, the machine stabilizes face pressure in real time and accurately restricts stratum disturbance and surface settlement, fully meeting safety specifications for urban power tunnel construction. In addition, the shield operates steadily and features user-friendly manipulation. It accommodates tunneling along the 500-meter small-radius curve, ensures smooth tunnel alignment and consistent construction quality, satisfying all technical requirements of this power tunnel project.

Tunneling officially commenced on December 2. Leveraging the outstanding performance of the NPT3700 slurry balance shield machine, the construction team scientifically optimized tunneling parameters, coordinated construction procedures efficiently and advanced excavation steadily. With tight and efficient construction scheduling, the machine reached the reinforced area of the receiving shaft on January 2 of the following year, marking the successful completion of full-line tunneling. During construction, the equipment delivered consistent performance and achieved an excellent maximum daily advance of 30 meters, equivalent to 30 rings per day, meeting all targets in safety, quality and progress.

The successful delivery of the project not only completes the critical supporting power tunnel for Wuxi Hynix Phase II, but also fills the application gap of shield construction in Wuxi’s power engineering field. It fully proves the superior adaptability and stable tunneling capability of the NPT3700 slurry balance shield machine for urban power tunnel projects. Furthermore, it accumulates mature practical experience for mechanized construction of regional power tunnels, accelerates technological upgrading of power infrastructure construction in Wuxi, and provides solid engineering support for the safe and stable operation of the local power grid and improved power supply for regional industrial projects.