Desing of Prestressed Post-Tensioned Bridge Girder

Abstract

Prestressed concrete is ideally suited for the construction of medium and long span bridges. It has been widely used for simply supported, continuous, balanced cantilever and suspension bridges. Here prestressed post tensioned bridge superstructure with Box girder and Igirder sections are analyzed and designed. Cost comparison for both the type of superstructure is done also. The contents of study is divided in the following six chapters Chapter 1: Covers the definition of prestress, methods of prestressing and application of prestressed concrete in the field of structural engineering. Various type of bridge superstructure are discussed at length. Chapter 2: Theoretical background of the study is given in this chapter. The design procedure i.e. preliminary dimensioning, properties of section, distribution of loads, finding of bending moment and shear, losses in prestress, checking of stresses and check for ultimate strength are explained step by step. Chapter 3: In this chapter longitudinal analysis of box girder as well as I girder is explained. It contains detailed sectional property calculation, load calculation, cable layout, calculation for prestress losses and finally check for flexural stresses and shear checks. Chapter 4: This chapter deals with detailed transverse analysis and design of both the type of super structure. It contains mathematical modeling, load calculation, transverse analysis and reinforcement design. It covers design of diaphragm and anchor block also. Chapter 5: This is a chapter in which complete rate analysis, quantity estimation for concrete, prestressing steel and HYSD steel and calculation of bill of quantity for both the type of superstructure are covered. Chapter 6: This chapter includes the important part of the work. Summary and conclusion of the present study and future scope of the work are discussed here. Appendix A: Covers tables for the freyssinet system. Appendix B: Staad.pro input files and analysis results are given in this chapter. Appendix C: General arrangement drawing, details of pretressing cables and reinforcement details are covered in this appendix.