This paper analytically examines the load-carrying capacity formula corresponding to the limit state 3 for steel I-girders subjected to shear force and the structural details on which the formula is based. The analysis result show that the ultimate strength can be calculated on the safe side by considering the aspect ratio correction and the bending-shear interaction in the Basler formula. In addition, formula for the required stiffness of vertical stiffeners to ensure the ultimate strength is proposed. A comparison with the proposed formula indicates that the vertical stiffeners have sufficient stiffness even under the current standards.
