Punching shear design with control perimeters subjected to asymmetrical bending

Abstract

Abstract A numerical procedure is proposed for asymmetrical plastic shear diagrams in punching control perimeters. Asymmetrical diagrams occur for edge and corner columns and for internal columns with biaxial unbalanced moments. The procedure intends to support the use of NBR 6118, which covers asymmetrical shear distributions due to internal moments of edge and corner columns. The study of columns in different positions of the slab proves the robustness and numerical efficiency of the proposal. The practical application of the procedure is tested against Model Code 1990, Eurocode 2, NBR 6118, and with combinations of criteria from these codes. The estimated capacities are compared with experimental data from the literature. Eurocode 2 initially presents better results, but this code does not consider moments with internal eccentricities in edge and corner columns. The Eurocode 2 evaluations are significantly improved by the inclusion of NBR 6118 criteria that partially apply these moments, whose asymmetrical shear diagrams can be determined by the proposed procedure.

Keywords

• flat slabs
• punching shear
• unbalanced moments
• plastic analysis