Shear strength of reinforced concrete circular cross-section beams

a proposed adequation of nbr 6118, item 7.4, related to shear strength of reinforced concrete beams is presented with aims to application on circular cross-section. the actual expressions are most suitable to rectangular cross-section and some misleading occurs when applied to circular sections at determination of vrd2, vc and vsw, as consequence of bw (beam width) and d (effective depth) definitions as well as the real effectiveness of circular stirrups. the proposed adequation is based on extensive bibliographic review and practical experience with a great number of infrastructure elements, such as anchored retaining pile walls, where the use of circular reinforced concrete members is frequent.