Some Design And Construction Issues In Deep Excavations And Shoring Design

This paper presents, firstly, a critical review of the current codes of practice on design and construction for retaining structures. The key factors impacting on the design and construction of shoring system is examined and discussed in detail. The importance of groundwater pressure on the design of a retaining structure is highlighted, which is as much as three times of the active soil pressure. Some design issues with respect to the SLS and ULS load combination and associated analysis are discussed through practical examples. A real case history in Sydney due to a burst water main behind the retaining wall is presented to demonstrate the significance of the groundwater pressure on deep excavation shoring design. A detail design approach is proposed as to how best the retaining wall structures could be designed to take account of the accidental water pressure induced by a burst water pipe. It is the Author’s opinion that this proposed approach will provide useful guidelines to the future retaining structure design.