Concrete-steel composite coupling beams. II: Subassembly testing and design verification

As shown in a companion paper, the embedment length of steel-concrete compo site coupling beams inside wall piers should be computed by incorporating t he contribution of the encasement. In lieu of detailed fiber-based analytic al techniques, a simple design-oriented model was developed and verified th rough testing of additional specimens with more realistic loading and bound ary conditions. Moreover, the influence of face-bearing plates and floor sl ab was examined. The developed design method results in longer embedment le ngth, and significantly enhanced energy-dissipating characteristics, streng th, stiffness, and ductility. Additional improvements are possible by using face-bearings plates. The contribution of floor slab toward stiffness of t he coupling beam is lost at small deformations and may be ignored. Slab par ticipation toward the strength of the steel-concrete composite coupling bea ms is different from that anticipated for conventionally reinforced concret e beams because of the amount of equivalent reinforcement provided by the f langes of the steel coupling beam.