Design Of Retaining Walls : System Uncertainty & Fuzzy Safety Measures

This paper explores some of the aspects of embedded retaining wall design, in particular the interrelationship between system uncertainty and the use of factors of safety in the various design procedures. System uncertainty reflects the mismatch between idealised retaining wall behaviour and what is observed in practice. This feature is modelled using the concept of fuzzy sets where the degree of support for the lateral stress state at failure is considered and related to current limit equilibrium design methods, measured lateral pressures and the results of finite element analyses. The proposed model is shown to have some advantages over current design practice.