The Aseismatic Performance Of Multistory Concrete Frame With Buckling-Restrained Braces

Under rare earthquake actions, the steel braces in steel bracing frames are easy to buckle in compression leding to a sharp decline in their stiffness and bearing capacities, thus the braces will no longer have effects. For this reason, some scholars have proposed BRB. Because this brace has constrain units to prevent the overwall buckling, this can ensure the brace in the elastic working stage under frequent earthquake actions and not prematurely buckling under rare earthquake actions. As a result, the BRB can not only provide lateral stiffness, but also consume more seismic energy by hysteretic behaviors of the steel core unit. Currently, because of the excellent significant characteristic of BRB, it is used more and more in engineering application. In order to understand the seismic performance of BRB acting on reinforced concrete frame structure, this paper designs three engineering examples whose structure type are respectively the pure frame, the steel bracing frame and the BRB frame, the comparison results of response spectrum analysis under frequent earthquake actions and time history analysis under frequent earthquake as well as rare eaiihquake actions indicate that:(1) The BRB and steel brace can improve the lateral stiffness of structures significantly.(2) The working performances of BRB and steel bracing frames under frequent earthquake actions are basically same.(3) Under rare earthquake actions, the BRB which can consume seismic energy and has significant damping effects is one good kind of brace types.