Study on Strategy of Optimizing Long Span Bridge Aseismic System

Long span bridges play an important role in the transportation system. It will cause great economic losses and casualty when long span bridges break down under an earthquake. To meet the specified objects of long span bridges under complex environmental conditions, the existing researches of long-span continuous girder bridges, rigid frame bridges, arch bridges, and cable supported bridges were reviewed. The structural characteristics and typical earthquake damage of different bridge systems were summarized. It is found that the dynamic characteristics of structures are essential to solve problems, such as excessive lateral displacement of the girder end and seismic resistance under different ground motion spectrum characteristics. Then feasibility of designing the dynamic characteristics through the control of mass, stiffness distribution and boundary conditions was discussed. Finally, the development of the seismic system of long span bridges was prospected. The results can provide references for seismic design of bridges.