Taking a CFST and spacial composite trussed continuous bridge with pier height of 50 m as the engineering background

the elastic-plastic three-dimensional FEA model was proposed by using OpenSees

the responses were analyzed based on IDA method by using 10 earthquake ground motion records from PEER seismic database.Curvatures of the most unfavorable section corresponding to the material damage were chosen as damage indices

and the regression analysis of the log function of capacity-demand ratio was performed.Then the expected damage probability was computed

and the vulerability curves of column and abutment were presented.We formed the system vulerability curve of bridge on the basis of the joint probability method.Several models were established for comparison to analyze the influence of pier span ratio and curvature radius on the vulnerability of the bridge.It is observed that when the difference between the height of the CFST lattice piers is not significant

the motion response of the first CFST lattice pier appears to be larger.A large number of rubber bearings between the pier and beam form the elastic connection and the hinged damping

can effectively reduce the bridge complete failure probability.Higher pier span ratio could lead to the rise of complete damage probability of bridge system.With the increasement of the bridge curvature radius

the damage probability increases;the arch structure of curved bridge is also beneficial for resisting the earthquake along the bridge.