Damage Evaluation in Steel Box Columns by Cyclic Loading Tests

Abstract

Bridge piers with hollow box sections are widely used in Japan in highway bridges. Unlike the columns in buildings, these piers are designed with high width-thickness ratios of component plates. This makes them susceptible to damage during a severe seismic event. To evaluate the damage sustained, a damage model is developed based on cyclic loading tests on hollow box columns modeling bridge piers. The box columns were tested under a constant axial load and cyclic lateral loads. It was found that the degree and type of damage sustained depends on parameters of the structure and the loading history. The overall behavior is assessed by means of a damage model that accounts for these effects. The parametric constants of the damage model are evaluated using test results. Since the residual strength is an important physical measure of the damage sustained, approximate expressions for correlating the residual strength and the damage index are suggested. The damage model developed in this paper is intended to be used to quantify the damage sustained under earthquake loading.