Chart development for the estimation of deflection in pre-stressed railway girder
In designing pre-stressed girder, calculating deflection is the necessary and rigorous step which one has to calculate at the end of the design process and tell whether the design girder is serviceable or not. If it is not, the designer has to change the cross-sectional dimension and repeat the step once again. But if the designer can certainly know the deflection of that structure in advance of those steps, he/she can eliminate such iteration. This research is intended to develop a program that plot a deflection chart for simply supported pre-stressed railway girder. To achieve the objective of the research, a simple user friendly and versatile program is developed that plots a deflection chart for simply supported pre-stressed railway girder. With the help of the findings and using the program one can control the deflection or camber of the pre-stressed member with the magnitude of the applied load and varying the eccentricity of the tendon profile both at the support and at the mid-span. And for a given cross-sectional geometry of a bridge, a pre-stressed member has not only a maximum,, but also a minimum span length limit in order to serve the intended function without failure.
Keywords: Tendon, Pre-stressed girder, camber, deflection