A Method for Concrete Creep Analysis Based on Viscoelasticity Theory

Long span and super width are the basic characteristics of a number of bridges in China nowadays. The behavior of these structures is obviously spatial,which leads to complicated creep effect in concrete.Precise results are usually unavailable when using 1-D finite element model due to its limitation.Solid-shell element is a solid degenerated shell element,which combines advantages of both convenient geometric description for solid element and simple model for shell element.Based on solid-shell element,the creep characteristics of concrete were taken into consideration by employing the generalized Maxwell viscoelastic model.With the creep model provided in China Code of 2004 Highway P.C.Bridge,the parameters of viscoelastic model were fitted.The viscoelastic constitutive relationship of solid-shell element was derived.Numerical examples showed the validity and efficiency of the proposed method and the necessity of 3-D creep analysis for concrete structures under complicated loading.