An Analytical Study of Existing Railway Bridge to Determine the Effect of Increasing Speed on Dynamic behavior

Abstract

In past few years, the interest in dynamic behavior has increased due to introduction of high speed train
all over world. Currently HST (High Speed Train), is under construction more than ten countries including India.
Existing bridges in India are not designed for HST. Under current design practice, dynamic impact factor is used for
consideration of dynamic impact but it is a function of loaded length only. However dynamics response of bridge
involves a number of parameter like frequency characteristics of bridge structure (i.e. the length, mass, rigidity of
individual member), the frequency characteristics of vehicle (i.e. the sprung and unsprung masses, the stiffness of
spring), the damping in bridges and vehicles, track irregularities, and the velocity of vehicle and so on. This paper
presents the result of analytical study undertaken on existing Railway Bridge which concludes that the dynamic
analysis is required after cutoff velocity of vehicle.