A Damage-Controlled Structure Using Buckling-Restrained Knee Braces

Abstract The basic concept of a damage-controlled (DC) structure is that by clearly separating the main frame from the energy absorption members, the main frame is kept within the elastic range and the seismic energy force is collectively absorbed by the members. The uniquely developed structural system embodying this concept is defined in this paper as a DC structure. Even when exposed to large earthquakes, the beam-to-column connections of the DC structure, being equipped with rotation capacity, allow seismic force to be absorbed by buckling-restrained knee braces designed to function as seismic-response-controlled members. Thus, the main frame can continue to be used by replacing only earthquake-damaged knee braces where necessary and the structural members can also be reused. In this paper, we discuss the designing process of the DC structure. First, the design flow is presented, as well as methods for designing the beam-to-column connection and buckling-restrained knee braces developed based on the results of previous tests. Next, a trial design of the DC structure is implemented based on the proposed designing methods.