Ground Effects on the Static Force Coefficients of a Closed Box Girder

Abstract:

As many existing or underconstruction bridges are of lower height from the ground, the height could probably become a key factor to the windinduced responses of bridges, hence it may have an adverse influence on the aerostatic and aerodynamic performances of bridges under wind loads. In this paper, wind tunnel tests and numerical simulation methods were adopted to study the ground effects on the static responses of a closed box girder. Frist, wind tunnel tests have been conducted to study the variation rules change laws of the static force coefficients correlated with the height from the ground of the closed box girder. It is found that ground effects will adversely affect the static wind stability of the closed box girder. Second， computational fluid dynamics (CFD) numerical simulations have been conducted to study the variation rules of the static force coefficients correlated with the height from the ground of the closed box girder. Through the CFD flow fields of the girder, ground effects mechanism on aerostatic performance of the closed box girder has been analyzed and described.

Key words:ground effects; closed box girder; static force coefficients; wind tunnel test; computational fluid dynamics (CFD); ground effect mechanism