Analysis of Stress Inhomogeneous Coefficient of a Continuous Rigid Frame Bridge during Construction Stage

The box section which can meet the requirements of wider deck is widely used in the construction of continuous rigid frame bridge. However, the shearing force lag is very obvious, which causes the inhomogeneous distribution of stress in the cross section, and it may threaten the safety of the bridge structure when it is serious. Taking a continuous rigid frame bridge located in Yunnan, China as an example, this paper establishes the finite element calculation model of the bridge to analyze the stress inhomogeneity in the construction stage. The results show that the shear lag coefficient of the section is constantly changing during the dynamic process of construction, with the increase of the length of the cantilever, the shear lag coefficient gradually converges to 1; prestress is the most important factor that causes the lateral inhomogeneity of the positive stress.