Recently, the "Silver Dragon" shield machine of the Shanghai Yindu Road river-crossing tunnel was launched once again, officially beginning excavation of the south-line tunnel.

The new Yindu Road river-crossing tunnel project runs from the planned Jingdong Road–Yindu Road in Xuhui District in the west to Pujin Road–Luheng Road in Minhang District in the east. It is constructed by Shanghai Tunnel Engineering Co., Ltd. (STEC) Shanghai Tunnel, with a total length of about 3.8 km and a design of double-level, two-way, 8-lane layout. After the south-line launch of the "Silver Dragon" shield machine, it will begin a 1.2 km tunnel excavation journey, crossing the Huangpu River for the second time.

During project construction, the project team continuously deepened the application of new processes and technologies such as fully prefabricated assembly techniques from the "inside" to the "outside," enabling river-crossing engineering construction to enter a dual channel of "safety" and "efficiency."

Keyword One: Efficient

Prefabricated technology reduces manual input by 60%

The internal structure of the Yindu Road Tunnel adopts fully prefabricated and assembled construction. Workers assemble tunnel components produced in prefabrication plants like "building blocks." While improving the quality of building components and construction efficiency, the new technology reduces manual input by 60% and effectively lowers noise, vibration, dust, and other impacts generated by construction, making tunnel construction safer, greener, and more efficient. In addition, prefabricated technology has effectively promoted the professional transformation of industrial workers, helping enterprises further optimize the structure of their workforce and advance corporate reform and transformation.

Keyword Two: Fast

Process duration accelerated by 60%

The project team applied the HUW prefabricated steel sheet pile insertion process in the Minhang open-cut section of Yindu Road. This process uses prefabricated steel sheet piles to replace mixing piles for water stop. Compared with traditional SMW construction method piles, it achieves "zero addition" of cement for the retaining structure and allows rapid excavation without waiting for the retaining structure to reach its curing age; compared with traditional Larsen steel sheet piles, it ensures water-stop performance while providing better rigidity. It further saves construction costs and shortens the process duration by 60%.

Keyword Three: Safe

Effective control of foundation pit deformation

During the open-cut operation of the tunnel, the project team used prefabricated concrete structures to replace traditional cast-in-place side walls, reducing on-site large-area rebar tying, mass concrete pouring, and large formwork installation and removal. While making operations greener and more efficient, the new process and construction method improve efficiency by about 40% compared with traditional cast-in-place methods, reduce the overall excavation exposure time of the open-cut section foundation pit by 30%, and effectively control foundation pit deformation.