Effects of soil-structure interaction on the damage of bridge piers subjected to earthquakes

Abstract

When an earthquake occurs, interaction between soil and a structure is obvious. However, the effect of this interaction is often neglected in most of the design of structures because of its simplicity, but this simplicity can be unsafe for the structures. This paper analyzes the influence of soil-structure interaction on the damage index of reinforced concrete (RC) bridge piers subjected to earthquakes. To achieve this aim, an RC bridge pier, which was constructed and tested in practice, was selected for analyses. The selected RC bridge pier was modelled using nonlinear hysteretic elements. The model of the RC bridge pier was verified by comparing the results obtained from the model with the experimental results. Time-history nonlinear analyses of the RC bridge pier subjected to earthquakes of different intensities were performed. The results of these nonlinear analyses were used for damage analyses. The results of damage analyses were compared to draw some conclusions as follows. The comparison results showed that the soil-structure interaction hardly changed the damage index of the bridge pier when the earthquakes were of moderate and weak intensity. However, the soil-structure interaction significantly increased the damage index when the pier was subjected to strong earthquakes. Therefore, instead of being ignored, the soil-structure interaction should be carefully analyzed when designing reinforced concrete piers subjected to earthquakes.