강사장현수교의 극한강도 평가를 위한 비탄성 좌굴해석의 적용성에 관한 연구

Abstract

Since a cable-stayed suspension bridge combining a cable-stayed bridge system and a suspension bridge has many advantages including reductions in the axial forces in girders and tensile forces in suspension cables, it has received attention from bridge engineers. However, there are few examples of this construction due to the lack of design experience and accurate analyses. In this study, the applicability of the inelastic buckling analysis to estimate the ultimate strength for the steel cable-stayed suspension bridge was discussed. The inelastic buckling analysis based on the bifurcation buckling theory is the eigenvalue analysis applying the tangent modulus to consider the inelasticity of members. Using the inelastic buckling analysis, the ultimate strength in terms of the whole system was calculated for an example model of the steel cable-stayed suspension bridge. And they were compared with the ultimate strength from the refined plastic hinge analysis, which considers the geometric nonlinearities and gradual plasticities of members. As a result, the inelastic buckling analysis gave good results within an error range of less than 8% for the example model. Therefore, it could be confirmed that the inelastic buckling analysis is applicable for the approximate estimation of the ultimate strength of the steel cable-stayed suspension bridge.