Abstract
This paper deals with the composite system composed of unbonded steel plate braces and a reinforced precast concrete panel. The concrete panel should be designed to prevent buckling of the steel plate in order to use the steel plate as the seismic elements. The required stiffness and the strength of concrete panel, that is the lateral bracing condition, is derived as the solution of the equilibrium problem. The bracing condition is affected by the distribution of bracing force and especially by the initial deflection of the steel plate. The analytical results were confirmed by the buckling test which is devised to measure directly the lateral bracing forces.
