Creep and Shrinkage Analysis of Composite Truss Bridge with Double Decks

Abstract

Abstract An innovative large span composite bridge with double concrete decks and steel truss webs was proposed to resolve the traffic jam in cities in this paper. Based on a practical application of simply supported composite truss bridge with a main span of 96.0m, the time-dependent structural behaviors due to creep and shrinkage effects were investigated, by using a hybrid finite element (FE) model. One of the web-deck composite joint was modeled by shell and solid element and embedded into the whole bridge model to investigate the local behavior of such composite joint structure. The exponential model of concrete creep and the implicit solution of concrete equations were introduced into ANSYS, and the concrete strain at any time can be solved by the hybrid finite element model. With time passed by, the deflection at midspan and maximum steel stress increases rapidly in the first year and the variation trend takes a more gentle course since most of the creep and shrinkage effect has been finished. The concrete stress and shear forces of headed studs gradually decreased. The decreasing velocity slowed down after one year. All the analysis results in this study could provide references for the design and construction of such composite truss bridges with double decks.