To investigate the dynamic response characteristics of steel bridges under seismic loads in complex environments, this paper uses ABAQUS finite element software to establish a three-dimensional structural model of a steel bridge. One synthetic seismic wave and two natural seismic waves (Chalfant Valley and San Fernando) are selected as input to simulate the dynamic response characteristics of the steel bridge along the X and Y axes under different seismic waves. Subsequently, the design of the secondary seismic defense line was completed by installing trans-rubber supports and anti-drop beam devices. The steel structure bridge was reinforced using the method of increasing the cross-sectional area, and its seismic performance was further optimized. The stress of reinforcing bars and concrete under frequent earthquakes and the bending moment at the pier base under rare earthquakes both meet the design requirements. The steel structure bridge designed using the seismic design method in this paper exhibits excellent seismic performance, meets the design requirements for steel structure bridges under different seismic actions, and complies with the seismic design optimization requirements of actual engineering projects.
