Stress Variation of External Tendons under Live Load in Prestressed Concrete Bridges

By using a computer program especially developed for externally prestressed concrete bridges, the stress variation of external tendons under live load in several typical spans of externally prestressed concrete box-girder bridges is analysed. The influence of span-to-depth ratio, the level of bonding between external tendons and the structure, and the spacing between deviators on externally prestressed concrete simply-supported bridges is discussed. The influence of the construction method, the ratio of external tendons to internal tendons, the number of continuous spans, and the layout of external tendons on externally prestressed concrete continuous bridges is investigated. The comparison of results between externally prestressed concrete bridges to similar conventional internally prestressed concrete bridges is also made.