Tatsuro Sakimoto

The out-of-plane buckling strength of through-type arch bridges☆

Abstract Numerical results for the out-of-plane buckling strength of theoretical models of through-type arch bridges are evaluated by the provisions of DIN4114, Japanese Specifications (JSHB), DIN18800 (draft), and a proposed formula. It is shown that DIN4114 and JSHB provide quite unsafe side predictions for all the numerical results, but DIN18800 and the proposed formula can give good predictions for the buckling strength of all the theoretical models. Further improvement considered in the proposed formula but not in DIN18800 is pointed out for a further revision of DIN18800.

Ductility of stiffened steel box member

Publisher Summary Ductility of structures depends on the ductility of key members like the end member of an arch bridge or the lower part of bridge piers. The chapter clarifies the effect of buckling parameters, the number of stiffeners in a flange plate, and patterns of repeated loading on the ductility behavior of members. FEM analyses were carried out on various box-section members changing such parameters under several repeating patterns of bending. The ductility of a member is studied on an equivalent stress-strain relation, where the equivalent strain is defined to include the shortening of a stiffened flange plate due to local buckling deformation. From these numerical results, one proposes a suitable load pattern for the cyclic load analysis and provides information about how to increase the ductility of the member by controlling the buckling parameters and the number of stiffeners. Seismic design method for complex steel structures like arch bridges is neither studied enough nor developed well. Engineers should set up new design specifications, and should realize and ascertain an expected performance of structures.