Reinforced Concrete Skewed Rigid-Frame and Arch Bridges

This paper presents a method of analysis and design by which the effects of skew on a barrel arch or rigid-frame bridge may be evaluated separately. The skew problem is thus resolved into a sort of secondary stress analysis in which the ordinary stresses for a rectangular structure are used as primary stresses. The procedure is extended so that final steel areas of reinforcement and unit stresses are determined as functions of the areas and unit stresses for the rectangular structure. Equations and transformations are derived for all applied loads and for volume changes. Criteria are presented for the effects of skew. For single-span or double-span structures with less then critical skew, no skew analysis is required. For structures with greater than critical skew, an independent adjustment is shown for analysis and design.