Numerical and physical simulation and full-scale measurement of local wind environment around slotted box girder with wind barriers

Abstract:

To reasonably assess the local wind environment around bridge decks, the CFD method was used to simulate the wind fields around a slotted box bridge with wind barriers. Experiments on the local wind environment of the model of Xihoumen Bridge girder were carried out, and field measurements of the bridge were conducted for verification. The wind barriers of the bridge deck were optimized and compared, and the wind environment characteristics of the slotted box girder with wind barriers were analyzed. The CFD method was adopted for simulating the local wind environment of the bridge deck installed with different types of wind barriers. The variation rules of wind speed at different positions of lanes along different heights were analyzed, and the influences of types, heights, and porosities of wind barriers on the crosswind reduction factor were quantified. Results show that the CFD method could provide highly accurate results and reveal more detailed characteristics of actual flow-fields around the bridge deck. The deviation was between 3% and 9%, which met the accuracy requirement of engineering application. Wind barriers had significant effects on reducing the wind speed under the condition of crosswind, and wind speed reduction on different lanes was about 30%–50%. The effective wind reduction regions of wind barriers were closely related to the height-width ratios, heights, positions, and porosities of the barriers, among which porosity was the crucial factor that decided the crosswind reduction effects of wind barriers. In addition, compared with integrated box girder, the wind speed on the downstream surface of the slotted box girder was obviously lower than that on the upstream surface due to the dredging effects of the center slot.