Spanwise deck sectional force correlation of bridge in motion in turbulent flow

Abstract

The response of very long span bridges due to wind action is well recognised to depend on the spanwise correlation of aerodynamic forces on the bridge section in turbulent wind flow. Previous analytical and model studies were often based on the spatial distribution of the incoming gusts and pressure correlation measurements on two-dimensional bridge section models. The bridge deck sectional forces are, however, generally more coherent than the gust eddies due to the wind excited vortices that occur and interact along the span. Wind tunnel model and full scale measurements on West Gate Bridge more than two decades ago had shown that the negative pressures under reattaching shear layers on the surface of the bridge deck were much better correlated than the approach fluctuating wind velocities. This paper further investigates this phenomenon in terms of sectional force correlation, in particular, on a full bridge model in motion with respect to the wind turbulence effects.