Considering the nonlinear behavior of bearings and elastic-plastic behavior of piers

the finite element model of a five-span simply supported girder bridge with unequal pier height is established.The longitudinal seismic responses of bridge due to different seismic waves are calculated by using a nonlinear time-history analysis method.The parameter influence of stiffness ratio of the adjacent span and collision of superstructure on longitudinal seismic displacement and internal force responses of simply supported girder bridge with unconventional configurations is researched respectively.The research shows that stiffness ratio of adjacent span has significant influence on the pier shear force

pier bending moment

top displacement of pier

girder displacement

relative displacement between pier and girder

and relative displacement between girders.With the increase of the difference of dynamic characteristic between adjacent spans

the influence of the adjacent span stiffness ratio on bridge response is more significant and bridge is easy to be unseating failure.Considering the collision effect

the effect of the stiffness ratio of adjacent span on bridge response depends on seismic wave and the collision between girders does not always aggravate the unseating failure.