Nonlinear Flexural Behavior of Prestressed Concrete Girder Bridges

Abstract

This paper presents a procedure to improve the accuracy of the classical grillage method for the nonlinear analysis of concrete girder bridges. The procedure uses equivalent element plastic hinge lengths that account for the actual mesh size instead of using a mesh-independent global plastic hinge length. A thorough review of the results of tests conducted on two 1/3-model prestressed concrete girders and a 1/3-model prestressed concrete girder bridge is undertaken in order to model the nonlinear properties of prestressed concrete girder bridges. The purpose of this review is to study the extent of plastification and plastic hinge length development as well as the evaluation of the validity of the grillage method for the nonlinear analysis of girder bridges. An \IL\dp\N transfer model is used to calculate the plastic hinge length for every beam element of the grillage based on the results from the experiments and other empirical models. The \IL\dp\N transfer model allows the use of empirical data obtained from tests on individual girders to model the response of a variety of bridge configurations subjected to different loading conditions. The equivalent grillage element plastic hinge length \IL\Dgp\N is calculated as a function of the grillage mesh size. A number of examples are presented to demonstrate the validity of the proposed method by comparing the analytical results of grillage analysis using the \IL\dp\N transfer model with those of laboratory and in situ tests on full-scale and model-scale prestressed concrete bridges. The proposed approach has a high potential for use in engineering practice because of the simple input requirement and improved accuracy.