A simplified formulation to assess shear capacity of circular RC cross-sections

Reinforced concrete (RC) members with circular cross-sections are widely used in structural and geotechnical engineering (e.g. columns in frame structures, foundation piles, etc.). Generally, for such members, the analysis is more complex than for rectangular cross-sections and the problem is not sufficiently investigated in literature. Circular shapes and uniform distribution of reinforcement along the perimeter cause some difficulties for a simple assessment of bending and shear capacity. This paper discusses a new formulation to estimate the shear strength of RC elements with circular cross sections investigating the cases with and without shear reinforcements. The proposed formulations are based on the significant contribution (improvement) given by the longitudinal bars homogenously distributed along the cross-section circumference (i.e. dowel effect) to shear strength.