Analytical Evaluation of Diagonally-Reinforced Concrete Coupling Beams Under Lateral Loads

This thesis evaluates various geometrical, reinforcement, material, and loading parameters that affect the behavior of diagonally-reinforced concrete coupling beams under reversed-cyclic lateral loading. To isolate the primary load-resisting components inside the beams, a two-dimensional nonlinear strut-and-tie analytical model is developed based on comparisons with measured coupling beam behavior from previous research. Most of these previous experiments were conducted on coupling beams free to displace axially, ignoring the axial restraining forces that develop in a coupled wall structure. The thesis shows that these boundary conditions can produce an unconservative evaluation for the design of the beams, in particular with respect to the diagonal strut in compression. The development of the horizontal beam reinforcement across the beam-to-wall joints can also induce critical conditions for the compression strut. Following the coupling beam analyses, multi-story coupled wall analyses are conducted to investigate the forces that develop in the beams and the wall piers.