THE STEEL RESTRAINT INFLUENCE COEFFICIENT METHOD TO ANALYZE TIME-DEPENDENT EFFECT IN PRESTRESSED CONCRETE BRIDGES

The concepts of restraint influence coefficient of steel on the time-dependent effects of prestressed concrete bridges due to creep and shrinkage are present systematically, and the expressions are provided. Then the steel restraint influence coefficient method to analyze time-dependent effect in prestressed concrete bridges is put forward, and a series of formulae which can calculate time-dependent stresses and strains in both concrete and steel and the deflections of bridge are introduced. This method can be used in both statically determinate system and statically indeterminate system, and to calculate time-dependent redistribution of internal force. These formulae give obvious physical meaning and are easy to use. Comparison between theoretical values and experimental results shows that the presented approach achieves higher accurary.