Envelope analysis equations for two-span continuous girder bridges

Abstract

In this paper, envelope analysis equations for two-span continuous girder bridges were presented by deriving the analysis equation for uniformly distributed loading, concentrated loading and moving loads (single and multiple wheel loads). Most bridge engineers are using special software’s to find the moment, shear and deflection envelopes for bridge girder, the complexity for this analysis increasing with the number of spans, most of cases are one-span and two-span continuous bridge, the two-span continuous bridge is more complicated which was presented in this paper, the same methodology can be applied in one-span bridge. The objective of this paper was to give all the bridge engineers direct equations for complete analysis (moment, shear and deflection) for two-span continuous bridge with more accuracy than most bridge software’s by adapting continuous moving of wheel loads rather than using interval check distance to move the concentrated loads as in most of bridge software’s. Pinned end boundary condition was presented here. The results were showed that shear envelope, moment envelope and maximum envelope deflection values were obtained by direct equations for two-span continuous girder bridges under single and multiple moving loads.