During the Xiangfu Road rapid reconstruction project, the Xiangfu Road Tunnel intersects with the operating Metro Line 1 at the Furong South Road intersection, with a minimum vertical distance of only 2 meters between them — the smallest clear distance among similar completed projects nationwide. Construction was extremely difficult, making it a controlling node project for the entire line. Through the innovative dual approach of “MJS reinforcement (omnidirectional high-pressure jet grouting method) + bench pile,” the Xiangfu Road Tunnel recently successfully crossed over Metro Line 1, marking the completion of the main structure of the 2.57-kilometer-long Xiangfu Road Tunnel.

On January 8, the reporter saw at the construction site that the intersection of the Xiangfu Road Tunnel and Metro Line 1 forms a construction area 39.4 meters long and 28.8 meters wide. “Although the area is not large, we worked on it for more than half a year, and the Municipal Urban Investment Group, the Municipal Rail Transit Group and others organized three expert review meetings in succession,” said Wu Jupeng, technical supervisor of the Guangdong Huasui project. In this area, the minimum distance between the base slab of the Xiangfu Road Tunnel and the Metro Line 1 tunnel is only 2 meters, and normal metro operation had to be ensured throughout construction.

To this end, the project ultimately adopted the internationally advanced MJS method: before excavation of the Xiangfu Road Tunnel foundation pit, 345 high-pressure jet grouting piles were driven underground to grout and reinforce the soil above and on both sides of the metro section, offsetting part of the earth pressure and preventing the tunnel from floating during soil excavation. The tunnel base slab was cast integrally with 24 uplift piles on both sides of the metro tunnel to form a “bench pile” structure, clamping Metro Line 1 beneath a “bench” 12.5 meters high, 28.8 meters long and 28.4 meters wide. “Through these two methods, the safety of metro operations was ensured during earthwork excavation and main structure construction of the Xiangfu Road Tunnel,” Wu Jupeng said.

During construction, the Municipal Rail Transit Group commissioned a third-party professional monitoring agency to conduct 24-hour uninterrupted automated monitoring of the Metro Line 1 tunnel structure within the construction area. According to a relevant person in charge of the Municipal Rail Transit Group, with one cross-section every 5 meters and seven monitoring points per cross-section, monitoring robots collected data every two hours, ensuring both the safe operation of Metro Line 1 and the smooth implementation of the Xiangfu Road Tunnel, laying a solid foundation for the early opening of the entire Xiangfu Road rapid reconstruction project. With the main structure of the Xiangfu Road Tunnel completed, the contractor is making every effort to advance ancillary structure construction such as interior decoration and mechanical and electrical works, and the tunnel section of the Xiangfu Road rapid reconstruction project is expected to be fully completed by the end of March.