Experimental study of connection between floor system and lateral force resisting system

This paper presents results from the experimental study a full-scale deformable connection used to connect the floor system of the gravity load resisting system with the lateral force resisting system (LFRS) of an earthquake-resistant building. Two configurations of the connection are studied. The first configuration consists of a buckling restrained brace (BRB) and steel-reinforced low damping laminated rubber bearings (RB), denoted as BRB+RB. The second configuration of the connection consists of a friction device (FD) and carbon fiber-reinforced low damping laminated rubber bearings (RB), denoted as FD+RB. The connections have stable, repeatable, and well-defined hysteretic nonlinear force-deformation responses that can limit the earthquake-induced horizontal inertial forces transferred from the floor systems to the LFRS. The BRB+RB post-elastic response is mainly controlled by the yielding force of the BRB, the isotropic hardening of the BRB, the dynamic effects on the BRB force-deformation response, and the RB force-deformation response. The FD+RB post-elastic response is controlled by the FD friction force, the effects of the sliding history on the FD friction force, and the RB force-deformation response. The BRB+RB has smaller elastic stiffness than the FD+RB. The steel-reinforced rubber bearings and the carbon fiberreinforced bearings have approximately linear-elastic force-deformation response. The post-elastic stiffness of the BRB+RB and the FD+RB is mainly determined by the RB stiffness.