The next generation of coupling beams

A collection of experimental, parametric, and analytical studies was carried out to further the understanding of the behavior and constructability of coupled core wall (CCW) systems. The research presented in this document focuses on a design approach of coupled core wall systems which concentrates on minimizing steel congestion while maintaining satisfactory structural behavior.; Several different configurations of coupled core wall systems were examined. The experimental portion of this research entailed reverse cyclic testing of representative subassemblies consisting of a coupling beam connecting two wall piers. The subassemblies are considered to be approximately ½ scale of a typical coupled core wall structure and the four different types of beams tested are: (1) a diagonally-reinforced concrete coupling beam (DBCB), (2) an unencased steel beam (SCB), (3) an unencased steel beam with a steel fuse link located at mid span of the beam (FCB1 and FCB2) and, (4) a composite steel/concrete beam utilizing a vertical web shear plate with headed shear studs (SPCB). Specimens (1) and (2) are types of coupling beams common to CCW structures. Specimens (3) and (4) are new proposed types of coupling beams.; The steel coupling beam (SCB) demonstrated superior stiffness and energy dissipation characteristics over all the other coupling beams. The confined core of the DBCB remained intact through 3% rotation, suggesting that at rotational demands of 3% or less it is not necessary to provide ACI-compliant confining steel to the diagonal bar groups. The fuse coupling beam demonstrated stable hysteretic behavior similar to that of the SCB specimen, and yielding of the fuse web was achieved while the main section of the beam remained elastic. The SPCB test failed to achieve sufficient composite action between the steel web plate and surrounding concrete. Further work is necessary to better engage the steel plate.; To investigate the overall structural behavior of coupled core wall systems with wall piers and coupling beams designed based on the recommendations of this research, nonlinear time-history analyses were performed on two prototype structures. Both structures had the same plan dimensions, number of stories, slab thickness, wall thickness, and floor-to-floor heights. The first structure was designed using a steel coupling beam, and the second was designed using a diagonally-reinforced concrete coupling beam. The need for special boundary elements in the wall piers was based on maximum concrete compressive strains at design loads. Properties of the coupling beams used in the analyses of the two structures were based on measured behavior obtained during the experimental phase of the research. (Abstract shortened by UMI.)...