Abstract: This paper presents a case history of foundation excavation for Huashan Road Station of Suzhou Metro Line No. 3. The foundation excavation supporting design methods were selected and optimized based on the site engineering geology conditions, supporting structure performance and construction technique. Different stages of this wide and large sized deep excavation construction were monitored, and the data were analyzed. The conclusions can be made as follow: For deep excavation supporting for a wide metro station excavation in saturated soils, the concrete raker with horizontal waler supporting method have the following characteristics: difficult in the deflection control, solder pile heaving and large axial stress in the reinforced concrete rakers. During the construction, the earth removal pattern should be optimized and the installation of raker support should be accelerated. The bottom concrete slab of the foundation should be poured immediately after the completion of the excavation so that the supporting system deformation can be controlled. In the design the heave of the solder pile and the larger axial stress in the concrete raker.

Key words: Metro Station, Large Foundation Excavation, Supporting Structure, Monitoring Measurement