Comparison of seismic performance of stiffened box columns having constant thickness plates and tapered plates

Abstract

Various methods have been proposed for improving seismic resisting performance of steel columns representing highway bridge piers. One such attractive method is to use linearly tapered steel plates at the critical part of a column because it is economical in terms of steel usage and useful in improving seismic resisting performance. In this study, several important issues related to the comparison of tapered plate columns with equivalent constant thickness plate columns are discussed in view of economical and seismic performance aspects. For comparison purposes an equivalent section is chosen for tapered section by using several constant thickness plate sections which satisfy a given design conditions. Here, the height of the column and axial load capacity are considered to be the key design parameters and are kept constant when designing the equivalent sections. By systematical investigation of influence of the structural parameters, the most suitable constant thickness plate is chosen.