Static characteristics of bridge deck sections of long-span bridges under simultaneous actions of wind and rain

The wind-rain-induced static characteristics test, was carried out by considering the static performance of a long-span bridge under the joint wind and rain field, taking an double-slotted box girder of bridge as the research object, utilizing the system of simultaneous actions of wind and rain built in the atmospheric boundary layer wind tunnel. Through analysis of the increment of wind-rain-induced static forces in joint wind and rain field comparing to wind-induced static forces in single wind field, the influencing rule of rainfall on the wind-induced static forces of bridge deck sections was obtained. Experimental results display the effect of change of flow field and water film on the surface of bridges on the wind-induced drag force of bridge deck sections is dominant. The effect of impact force of rainfall on the wind-induced drag force of bridge deck sections is less influential. The gravity of raindrops, impact force of rain, change of flow field and water film on the surface of bridges all have certain contribution on the wind-induced lift force of bridge deck sections. The change of flow field and water film on the surface of bridges play a more important role on the wind-induced pitching moment of bridge deck sections comparing to the gravity of raindrops and the impact force of rainfall. The result shows that change of flow field and water film on the surface of the bridge show obvious influencing on static characteristics of bridge.