STUDY ON OPTIMIZATION FOR SYSTEM RELIABILITY OF SOIL-SUPPORTED STRUCTURE SUBJECT TO SETTLEMENT

Abstract

A superstructure and a substructure are designed separately in the general design method, since an interaction between them is very complicated. The present paper proposes a procedure of optimization for system reliability of a soil-supported structure as one system. A plate girder bridge is taken up as an example of a structure. Ununiform settlement between an abutment and a pier which is generated by consolidation of a clay layer influences on the degree of safety of a main girder. Under such a condition, the optimum safety factors of a main girder and an abutment are investigated with some numerical examples. The optimum safety factors obtained are close to those given in the current design specifications.