In order to investigate the conditions of damage and failure of concrete-filled steel tube(CFST) arch bridges

considering the structural and mechanical characteristics of CFST arch bridges

the dual damage criteria assessment models of the various components based on deformation or strength and energy were developed. The nonlinear seismic response of CFST arch bridges was analyzed by finite element method and the fuzzy evaluation method of seismic damage based on fuzzy theory and analytic hierarchy process was studied. Finally

taking a long-span CFST arch bridge as example

the damage index of the bridge was 0.150

0.152

0.172 and 0.318 respectively when the seismic peak acceleration was respectively 0.1g

0.2g

0.4g and 0.8g. The results show that the CFST arch bridge is slightly damaged under the earthquake when the seismic peak acceleration is 0.4g

and the bridge is damaged moderately when the peak acceleration is 0.8g.