Abstract: There are many significant drawbacks in traditional cast-in-place concrete structures for excavation engineering, such as large construction site impact, low efficiency, and high energy consumption. With the acceleration of urbanization and the demand for sustainable green development, many new prefabricated assembled support technologies have emerged for excavation support engineering. Prefabricated assembled support structures have the characteristics of low cost, short construction period, and easy quality control. The Flying Fish 0401 project located in the Lingang new area of Shanghai is introduced, which excavation area is about 80,500m², with a depth of 6.00-6.45m and tightly surrounded by three municipal roadways and pipelines. By considering the characteristics of the excavation depth, large area, high permeability coefficient, and analyzing its stress characteristics, a prefabricated support system was successfully implemented in the large-area excavation engineering. The excavation support structure took a fully prefabricated green support scheme consisting of prefabricated steel HUW panel support and precast inclined struct (PIS construction method) to replace the traditional cast-in situ sheet pile retaining wall and horizontal internal support design. The monitoring results show that adopting those technical measures can ensure the safety of the excavation and its surrounding environment, which provides a valuable reference for related projects.

Key words: Prefabricated Assembled Support Structure, Precast Inclined Struct, Unsupported Excavation System, Environment Friendly Excavation Support System