INVESTIGATION OF PERFORMANCE OF BRIDGE ABUTMENTS IN SEISMIC REGIONS

Bridge abutments designed using the conventional strength-based approa ch have performed satisfactorily when located above the water table. O nly some of the assumptions used in the conventional approach are inde ed conservative. This paper attempts to quantify the extent of the inf luence of various assumptions on permanent abutment displacement. Abut ment displacements were computed by modifying an existing rigid-plasti c model to take into account the increase in residual lateral thrust c aused by cyclic loading. A database of displacements for typical short and tall abutments designed using the conventional approach was gener ated from 22 recorded excitation histories obtained in earthquakes wit h a magnitude of 6.5 to 7.0. The study shows that the abutments design ed according to the conventional approach will not undergo large displ acements in moderate to large earthquakes.