Methodological Study of the Ultime Limit Section in Reinforced Concrete Under Biaxial Bending and Axial Compression

The complexity of the geometrical shape in reinforced concrete amplified the difficulties ofshearing resistance in the boundaries limits state in particular for a section, which issubmitted to the eccentrited biaxial loading (biaxial force plus bending).The difficulties in this study results in the determination of the ultimate forces Nu, Muxand Muy and the relationship between them. These difficulties are essentially du to thegeometrical shape, the steel disposition and the law behaviour of the concrete and steel. The main objectif of this paper is to present a methodological study based on the integration numerical method that would determine the equations of the interaction curves fitting for the determination of the steel sections and the verification of the shearing resistance.