WIND TUNNEL TEST ON WIND-SAND FLOW FIELD AND WIND-SAND LOAD OF BUILDINGS

Wind tunnel tests are carried out to study the characteristics of wind-sand flow field, including wind speed, turbulence and sand concentration distribution. Three cases are tested with the same wind speed and different amounts of sand falling. Based on the results of flow field analysis, the wind tunnel high frequency dynamic balance force test is carried out to explore the law of wind pressure and sand impact force on the windward face of buildings in the wind-sand flow field, and the variation law of wind-sand load along the direction of building height is studied by using the method of dividing windward face into equal parts. The results show that the distribution of sand concentration under the wind-sand flow field is related to the falling sand amount and the height of windward surface. Sand particles have a certain weakening effect on wind speed and a certain enhancing effect onturbulence, and the greater the sand concentration is, the more obvious the weakening and enhancing effect will be. The sum of the wind pressure and sand impact force on the windward face of the building under the wind-sand flow field increases with the increase of the height of windward surface and sand concentration. The wind pressure increases with the increase of the height of windward surface but decreases with the increase of sand concentration; while the impact force of sand grains decreases with the increase of the height of windward surface, but increases with the increase of sand concentration.