Ultimate limit state design of reinforced concrete shallow shells under seismic‐type horizontal loads

This paper deals with positive Gaussian curvature reinforced concrete (RC) shallow shells and panel shells, including monolithic connection between the shell itself and its edge elements, such as columns, diaphragms, walls, etc. Connections of such shells with edge elements are subjected to additional bending moments and shear forces due to horizontal loads. Such structures are at particular risk in seismic zones. Mutual work of shell and its diaphragms under ultimate horizontal forces is very important, but research in this field is rather limited. In spite of numerous collapses due to failure in the above‐mentioned connections, there are not enough practical investigations, considering their failure schemes, required for ultimate limit state analysis. Such investigation can be carried out by testing scaled shell models. This study is focused on experimental and analytical investigation of scaled shell models, subjected to horizontal loads that grow up to the failure of the tested specimens. For numerical analysis of the models, limit equilibrium method and mini–max principle are used. It provides a theoretical basis for design of the shell–edge element system to ultimate horizontal loads, considering the limit state of the structure. The edge element type, investigated in this study, is an RC element that has monolithic connection with the shell and able to take horizontal loads. Using the mini–max principle, the real structural load‐bearing capacity in the ultimate state of the structure is calculated without its under‐ or over‐estimation. It is the main reason for improving the accuracy of the analysis. The numerical example demonstrates that analytical results, obtained for the tested models, are close to the experimentally obtained data. The proposed methodology allows more wide application of effective spatial RC structures in seismic regions.