Study On Aseismic Performance Of Buckling-restrained Brace In The Bridge

The bridge is an important part of traffic hub, which plays an important role for economic development and people trips. If a seismic occurs, it will lead the destruction of bridge; not only this can threaten people’s life and property security, but also will influence relief of disaster work after the shake. Buckling-Restrained Brace as a seismic response damping device, because of its remarkable advantage, it has been widely used in the field of construction engineering. However, its application is less in bridge, so this paper proposes buckling-restrained brace is installed on the bridge, then we can draw the conclusion that the buckling-restrained brace can be used as a bridge seismic design concept.In this thesis, with a 3 span equal section continuous beam bridge and a 3 span variable cross-section continuous beam bridge as example. At first, shock absorption effect of buckling-restrained brace is installed on the equal section continuous beam bridge is investigated with the finite element software Midas, in addition, brace damping effect to equal section continuous beam bridge with different angle of braces, different section area of braces, different length of braces, different kinds of earthquake wave are compared. Based on analysis above, the best scheme of damping is found out; secondly, double column piers with herringbone type of buckling-restrained braces is analyzed in the earthquake wave. Then, shock absorption effect of buckling-restrained brace is installed on the variable cross-section continuous beam bridge is investigated with the finite element software Midas, including the damping effect of the variable cross-section continuous beam bridge with brace and different angle and number of braces. In addition, brace damping effect to variable cross-section continuous beam bridge with different supporting style of brace.The results show that: the hysteretic curve of buckling-restrained brace is full, it has a good energy dissipation performance, the bearing and displacement of fixed pier and beam body under earthquake action are reduced obviously, and the different scheme of brace has an obvious influence on the damping effect. Because different earthquake wave will lead different bridge responses, so choosing the reasonable scheme of brace should base on the real seismic date and seismic risk assessment, which helps to achieve more satisfactory damping effect.