Abstract
A three-span continuous beam bridge can be designed most reasonably if considered as a beam of gradually varied cross sections. But it is designed in most cases, as a beam of a uniform section, because of the complexity of general equations determining bending moments of beam of gradually varied cross sections, indicated in bibliographies. In this paper the auther proposes, as an aid to designing bridges, a simplified method to calculate bending moments of a three-span continuous beam of gradually varied cross sections by using nomograms.
