Abstract: With the increasing complicity of adjacent environment of deep excavations in the urban area, structures with internal supporting systems receive a wider application. The arch beam system is among the most popular type due to its excellent load transfer and wide working zone. This paper presents a case history of using a semicircular ring truss system combined with the soil nail wall in the deep excavation in soft soils in Zhongshan. The characteristics of this supporting structure are also introduced.

Key words: Deep Excavation in Soft Soils, Semi-arched Ring Truss Beam, Internal Supporting Structure