MANUAL ANALYSIS AND DESIGN OF POST TENSIONED PRE-STRESSED CONCRETE T-BEAM SEGMENT BRIDGE USING PROTO-TYPE MODEL

The report examines in detail the application of segmental precast T-Beam girder construction in achieving long spans in bridge structures. Numerous examples from throughout the world indicate that such construction can provide an effective means of achieving long span in the range of 100 to 500 ft. Used segmental pre-cast bridge structure member is manufactured in a number of short units which during erection are joined together, end to end, and post-tensioned to form the completed superstructure. Cantilever concrete T-Beam girder bridges composed of precast reinforced and pre-stressed concrete beams with a T- cross section and a cast-inplace top slab are frequently used for medium spans due to their competitiveness. The service behaviour of such bridges is very much influenced by their segmental construction, due to time-dependent materials behaviour that makes it difficult to accurately predict the stresses, strains, and deflections. A 1:2 scale model of a twospan cantilever bridge was tested in order to study its behaviour during the construction process and under permanent loads. The analysis results were compared with analytical predictions obtained by means of a prototype model developed for the nonlinear and time-dependent analysis of segmentally erected, reinforced and prestressed concrete structures. Generally good agreement was obtained, showing the adequacy of the model to reproduce the structural design of the different elements in the post-tensioned pre-stressed bridge structure.