Verifying the stability of unconventional cable-stayed bridges with an innovative approach

Abstract

The paper presents an unconventional structural scheme of cable-stayed bridge, describes its structural behavior with an approach of beam-column with an intermediate elastic restraint, referred to imperfect initial shape. The stability verification of a considering structure is carried out by a simplified analysis, which is based on a proposed computational method. The suggested computationalmethod covers the requirements of the design codes for the direct method analysis: physical, geometrical imperfections and structural analysis based on the deformed structure geometry. Besides that, the concepts of equivalent imperfections and generalized imperfection factor are discussed. The European Standard, Eurocode 3 (EC3) provides two alternatives for flexural buckling verification of the beam-columns by interaction formulae. This paper presents numerical study performed using nonlinear solver of ANSYS for calculation model based on previously mentioned concepts. The errors of the comparison analysis between computer aided analysis and interaction formulae covering both methods declare the accuracy of concepts application. In addition, a numerical study performed of double-level under-deck cable-staying bridge with an approach of the direct method both using nonlinear solver of ANSYS and suggested computational method show that the proposal is safe and accurate. Analysis results incorporate verification of bridge stability for both symmetric and asymmetric load cases.