ANALYSIS AND DESIGN OF SLAB BRIDGES FOR IRC LOADS

Abstract

Bridges, which are most important structures in present day life, may be of short span or long span . A slab deck bridge prOves to be economical for relatively shorter spans. Various methods are available for analysis of slab bridge decks. Among these methods, Grillage Analogy Method is a popular computer oriented method, since it is easy to use and comprehend, relatiVely inexpensive and is reasonably accurate for a variety of bridges: In this method, the bridge deck is idealized into a grid which has members in both directions. The load acting on deck is to be converted into equivalent nodal loads. The structure is then analyzed by matrix method using stiffness approach. A computer program has been developed for this purpose which has a data base for IRC live loads also. The program generates IRC vehicle and moves it on the deck gradually in longitudinal direction. Effect of impact is also taken into account. The interpretation of results obtained by analysis with the help of computer program has been discussed to enable the engineer to design the deck slab. Effect of span on design moments and depth requirement has been studied. Also effect of different loadings has been observed.