SEISMIC RESPONSE OF BRIDGES WITH NON-LINEAR SUPPORTS

Seismic response of long bridges with friction type sliding support is investigated. The superstructure (bridge deck) and the substructure (piers) are idealised using one-dimensional bear elements. The response of the system is obtained to real earthquake ground excitation (El Centro ۱۹۴۰). The force-deformation behaviour of the sliding support is modelled as elasto-plastic with very high initial stiffness. The resulting non-linear equations of motion of the system are solved numerically using step-by-step method. The response of the isolaied bridge structure are compared with those without sliding support in order to investigate the effectiveness of the sliding support. In addition, the effects of the coefficient of friction on the response of the system is also investigated. It is shown that the sliding support is quite effective in reducing the seismic response of the bridges.