Research On Influence Of Aerodynamic Shape And Roughness On Wind Load Characteristics Of Square Super High-rise Buildings With Cross-section Modification

Wind disaster is a common disaster in nature.Light-weight and high-rise buildings are sensitive to wind loads.The wind-resistant design has become an important aspect of super high-rise building design.Studies have shown that the rounded treatment of square-section super high-rise buildings can reduce the structural wind load.However,to pursue the beautiful and novel appearance of the building,some buildings add the design of the arc edge based on the fillet.In addition,the decoration components such as ribs on the surface of super high-rise buildings lead to the increase of surface roughness.The arc edge design of the building and the change in the surface roughness of the structure will affect the wind pressure distribution on the building surface.However,there are few studies on the influence of different arc edge bulge rates and surface roughness on the wind load characteristics of square super high-rise buildings with cross-section modification.China’s relevant building codes and standards have not been described in detail.The design wind load value of the retaining structure is not clear.Therefore,it is necessary to study the wind load characteristics of super high-rise buildings with a combination of round corners and bulge edges comprehensively.It provides a reference for the wind resistance design of such super high-rise buildings.In view of the above problems,this paper completes the wind tunnel pressure test.The effects of arc edge bulge rate,surface roughness,and wind direction angle on the wind load of square super high-rise buildings with cross-section modification are analyzed.The main work and conclusions of this paper are as follows:(1)The super high-rise buildings with a combination of round corners and bulge edges were studied with the changing curvature radius of the edge under rough and smooth walls.The distribution of average and fluctuating wind pressure coefficients on the buildings under different wind directions was analyzed.(2)The overall force coefficient and power spectrum of the super high-rise buildings with a combination of round corners and bulge edges structure were compared and analyzed.The effects of different arc edge bulge rates and different surface roughness on the overall lift and drag and power spectrum of the structure were studied.With the increase of the arc edge bulge rate,the drag coefficient of the squarelike section model decreases gradually,and the peak value of the lift time-frequency power spectrum decreases.(3)The non-Gaussian characteristics of the wind pressure time history of each building were analyzed,and the division standard and distribution area of non-Gaussian wind pressure was defined.(4)The peak factor was calculated by various methods and the results were fitted.The wind load of the building envelope was estimated by using the method of probability statistics and the method of building load code.The variation of extreme wind load along height was analyzed.The recommended values of wind load zoning for each facade under Class C landform were given.