On January 9, the "Hualong" shield machine was successfully received for the Nanjing Gongtang–Huake 220 kV Line Project, which was designed with the participation of China Energy Engineering Group Jiangsu Power Design Institute. This marks the full completion of civil works for the core project of the Nanjing southern power grid upgrade, and the project has officially entered the electrical construction phase.

The Gongtang–Huake 220 kV Line Project is located in Jiangning District, Nanjing, Jiangsu Province. With a total length of 12.9 kilometers, it serves as the core north-south interconnection channel of the Nanjing southern power grid and a key milestone in the regional power grid upgrade.

The project is expected to be fully operational by May 2026. Once completed, it will rebuild the ring-network power supply structure among the Gongtang, Huake, and Longshan substations, significantly enhancing the power supply reliability and mutual support capability of the Nanjing southern power grid. It will also effectively release surplus power from the 500 kV New Dongshanqiao Substation to meet the rapidly growing demand for high-quality electricity in the region.

The shield tunnel completed this time has a total length of 800 meters, and the construction faced dual challenges from complex geological conditions and the surrounding environment throughout. The geological conditions at the site are highly unusual: the foundation pit of the shield launching shaft exhibits the extreme characteristic of being "soft on top and hard at the bottom," with low-bearing-capacity silty clay in the upper section and extremely hard weathered rock strata in the lower section. The tunnel mainly passes through weathered rock strata, where the rock surface is uneven and interlayers are widely distributed, posing great challenges to precise construction control. More critically, the tunnel alignment must pass beneath the West-East Gas Pipeline and existing railways, and also pass alongside existing overhead line foundations at close range, placing extremely high demands on engineering design and construction safety.

Faced with multiple construction challenges, the project team consistently upheld the philosophy of pursuing excellence and prioritizing service, providing high-quality agency services throughout the process. The team worked from the design source, promptly proposing reasonable suggestions, proactively collaborating with the owner and construction units to resolve various difficulties during construction, and efficiently advancing the project schedule. Ultimately, the shield tunnel breakthrough was completed in only 84 days, not only greatly shortening the construction period but also setting the fastest record in Nanjing for shield tunneling in composite strata at 18 rings per day.