Wind Interference Effects Of A Ventilated Supertall Building On Its Neighboring Supertall Building

Super high-rise buildings usually have a large height-width ratio,light weight and high flexibility,and are very sensitive to wind loads.Therefore,wind loads have become one of the main controlling loads in the structural design of super high-rise buildings.Some studies have shown that using aerodynamic measures such as opening local ventilation slots to reduce the wind load and structural response of super high-rise buildings is a low-cost and effective method to improve the wind resistance of super high-rise buildings.However,the super high-rise buildings in the core area of the city are dense,and the partial ventilation slots of a building may have a wind interference effect on the adjacent super high-rise buildings.This wind interference effect may be beneficial or unfavorable to the wind resistance of the adjacent super high-rise buildings.Especially when there is an adverse effect on the local or global wind load of the super high-rise buildings,ignoring the interference effect of the open ventilation slots on the surrounding buildings may lead to underestimation of the wind load and structural response of the surrounding super high-rise buildings,resulting in a risk of wind resistance design.Based on the existing literature search,there are very few literatures that study the effect of local ventilation slots in super high-rise buildings on the wind load and wind effect of super high-rise buildings nearby.In this paper,two methods of numerical simulation and wind tunnel test are used to study the wind interference effectof the imaginary prism super high-rise building and the actual super high-rise building with local ventilation slots on the surrounding super high-rise buildings,including:(1)First,the numerical simulation method is used to conduct numerical simulation of the surface wind pressure on the international common high-rise building standard model(Commonwealth Advisory Aeronautical Research Council,CAARC)and comparative analysis with the data of the wind tunnel test,so as to obtain reliable numerical simulation parameters.Including: Reynolds number,turbulence model,mesh thickness,mesh type,etc.The results show that the SST turbulence model is close to the results of the wind tunnel test;coarse meshes often lead to convergence failure.When the mesh is refined to a certain degree,it can achieve mesh independence,that is,dense mesh will not affect Calculation results.For simple geometric models,structural grids can easily and quickly generate good-quality grids while meeting the calculation accuracy requirements,saving calculation costs.Finally,the results of the numerical simulation of the adjusted parameters are compared with the results of the wind tunnel test,and the error is within the acceptable range,thus verifying the rationality of the selected calculation parameters of the numerical simulation in this paper.(2)After verifying the feasibility of numerical simulation using the CAARC standard model,this paper carried out experiments on models with different shapes and different spacing.Open the ventilation slots at 1/2 and 2/3 of the model,and study the relationship between the average wind pressure coefficient on the surface of the downstream building and the distance between the two buildings in tandem.Extract the profile of the simulated wind field and analyze the flow lines between the buildings.It is concluded that different building spacing will affect the flow field changes between the two buildings,resulting in the presentation of different wind pressure coefficient results.The results show that when the two buildings are within 4 times the width of the building,the ventilation slots of the upstream building can reduce the surface wind pressure coefficient of the downstream building.In different working conditions of single-layer slotting and double-layer slotting,it is found that when the upstream building opens two-layer ventilating slot,because the ventilating slot destroys the integrity of the airflow and disrupts the wake frequency of the wind,this situation is most conducive to reducing the surface wind pressure coefficient of the downstream building.(3)Taking two adjacent super high-rise buildings Guangzhou International Financial Center(IFC)and Guangzhou Chow Tai Fook Financial Center(CTF)as examples,the wind tunnel test of high-frequency base force balance(HFFB)with interference effect is carried out,and the influence of the equipment layer of the open Guangzhou international financial center as the wind trough on the wind-induced response results of the basement overturning moment response of its Guangzhou Chow Tai Fook financial center is mainly discussed.The results show that IFC can reduce the mean base bending moment coefficient in y-axis and peak base bending moment coefficient in x-axis by 29.65% and 15.1% respectively after opening all the ventilation slots,which also has a significant effect on the acceleration response.While the average bending moment coefficient of CTF is almost not affected by IFC,but the peak bending moment coefficient of x direction can be increased by 16.04%,the peak overturning moment coefficient of y direction can be increased by 15.413%,and the peak acceleration can be reduced by 28.477%.However,in the same case,the decrease of peak acceleration is accompanied by the increase of CTF transverse bending moment response.The reason for this is that when CTF is located directly below IFC,the high-energy frequency band of the power spectral density of the crosswind aerodynamic load of CTF is obviously shifted to a lower frequency by the design of the ventilation slot on IFC.It can be seen that the wind-induced response of CTF will be amplified or reduced,and the specific change depends on the reduced natural frequency of CTF's own structure.