Concept and Design Methodology of Redundancy in Braced Excavation and Case Histories

Abstract

The conventional design methodology of deep excavation retaining structure generally proceeds elements by elements, consequently, the retaining structures are/may be lack of redundancy. This could lead to catastrophic collapse of retaining system. It is necessary to introduce the concept of redundancy into the design of retaining structure and develop the design methodology based on redundancy. In this paper, redundancy of deep excavation retaining structure is classified into five aspects. Necessity and importance of each aspect are explained. A method to evaluate and quantify the retaining structure redundancy is presented through the analysis of an example. Two typical case histories are studied to reveal the redundancy problems that may exist. Finally, a series of measures are proposed to increase the redundancy of deep excavation retaining structure.