A Recommended Method for SC Wall Design-Evaluation Regarding the Elasto-Plastic Behavior Under Beyond Design Basis Seismic Loading

Steel Concrete Composite Wall (SC-Wall) is a unique composite structural component designed and used for shield building wall in new nuclear power plants construction. The composite function (action) of steel-plate and concrete is through the use of embedded studs, which are designed in an appropriate pattern to secure the connections between concrete and surface steel-plates. Thus the behavior of studs (primarily shear behavior) determines the composite state and its functions for serving as an integrated one-piece (or monolithic) section. For elastic state (linear) and ultimate state design, ACI 318 / 349 and recent published design specifications provide formula / equations for shear design-evaluations between plate stud and concrete; but for Beyond Design Basis (BDB) loading conditions, since the section behaves in elasto-plastic (or plastic) state, the constitutive relations among plate-stud-concrete have not yet established in current prevailing codes / or standards. Considering this situation, this paper is contributed to investigate the section behaviors of SC wall subjected to above BDB seismic loadings, provide recommendations for constitutive relations to reveal the actual strain-stress conditions and composite states, and further provide criteria suitable for section design and evaluations under such a circumstance. This research and investigation are based on an analytical methodology and physical model.