Abstract: The support system for the excavation of the pedestrian underpass ramp at Wusheng Road East in Wuhan used the small diameter perforated pilot pipe grouting composited supporting technique. The supporting structure analysis method of the small diameter perforated pilot pipe grouting inside the excavation wall is introduced in this paper. The analytical results indicate that bending resistance of the wiremesh shotcrete wall in the vertical direction has to be considered in order to meet the bending demand. Among the bending resistance, the rolled steel and the shotcrete facing can be analyzed as the reinforced concrete element. The strengthening effect at the bottom of the excavation also needs to be considered in order to meet the requirements on the preventing of the bottom heaving.

Key words: Excavation Projects, Small Diameter Perforated Pilot Pipe Grouted Wall, Internally Supported Wall, Composite retaining and protection