Seismic Analysis of Slender Coupled Walls

The dynamic response of multistory reinforced concrete coupled walls was evaluated from the perspective of linear models based on response spectra, modal analysis, and reduced effective stiffnesses. This study indicates that: (1) Linear models based on plausible reductions in stiffness and reasonable ductility demands in the structural components can provide an adequate basis for designing reinforced concrete structures; (2) the design of multistory reinforced concrete coupled walls must include the effects of concrete cracking, slip of the reinforcement, and ductility demands in the structural components. Special attention must be given to the redistribution of flexural moments and shear forces between the wall in tension and the wall in compression; (3) natural frequencies of reinforced concrete structures can be significantly reduced by cracking caused by shrinking of the concrete; and (4) to avoid catastrophic collapse in coupled wall systems, the structural system should be designed such that the coupling beams are the only members that suffer severe yield cycles, and their energy dissipation capacity is utilized before the walls are subjected to high or extreme ductility demands.