Improved Design and Analysis of Prestressed Concrete Girders

摘要

A design program and an analysis program were written to take advantage of more exact analytical methods. Both programs employ a very accurate analytical model that uses the actual stress-strain relationships for concrete and prestressing steel. The model also includes the effect of additional prestressing steel strains that occur during live loading. In addition, the analysis program incorporates the fact that the strength properties of prestressed concrete bridge girders are not deterministic, but rather are random variables. Both programs can accept several standard cross-sections or any girder cross-section made up of a combination of rectangular and triangular areas. The design program, named MXPSD (More eXact PreStress Design), designs for flexural stresses at midspan. The analysis program, named PROCAT (PRObabilistic Capacity Analysis Tool), performs either a deterministic, mean-value analysis or a probabilistic analysis.