Feasibility Study on Utilizing Self-centering Structural System for Typical Highway Bridges in Iran

Recently, in developed countries, a variety of self-centering structural systems have been developed using precast concrete bends and Accelerated Bridge Construction (ABC) method to reduce construction time, increase safety, reduce seismic damage, reduce repair and reconstruction costs, and increase seismic resiliency. In this system, bridge bents are constructed by precast elements tied together with post-tensioned tendons such that under the effect of lateral seismic forces, they are able to rock and self-center back to their original configuration. The use of this system greatly reduces the residual displacements and the seismic damage. Also, due to the use of prefabricated elements, the construction speed of the bridge is significantly increased. This paper compares the seismic performance of one type of the self-centering structural system with the conventional structural system for three typical highway bridges constructed in Iran. An analytical model for simulating nonlinear behavior due to the rocking motion in the self-centering system is first developed and verified by comparing the analytical response with the experimental results. Then, the concrete bends of the three typical bridges in Iran are modeled and analyzed once as a conventional system and once as a self-centering system, and the seismic performance of these two systems is compared with each other. The results of this study indicate that in spite of a modest increase in maximum lateral drifts, the residual drifts are substantially reduced when the conventional system is replaced by the self-centering system.