Study On Wind Loads And Wind-induced Dynamic Response Of Parallel Rounded-corner Arc-edge Triangular High-rise Twin Towers

The acceleration of urbanization has promoted the rapid development of high-rise buildings everywhere.Generally speaking,high-rise buildings tend to adopt regular sections,such as rectangular and circular sections.However,in recent years,there has been more and more rounded-corner and arc-edge triangular high-rise buildings,including Shanghai Tower,Guangzhou West Tower and so on.At present,there are relatively few researches on rounded-corner and arc-edge triangular high-rise buildings,most of which focus on the single building.Recently,quantities of engineering projects appear in the form of twin towers,such as the twin towers of Hangzhou New World Global Center which has prominent problems of wind load interference.Therefore,it is of great theoretical significance and application value to study wind load,wind-induced dynamic response and interference effect of triangular high-rise buildings with rounded corners and arc edges.In this paper,wind tunnel tests are carried out on round-corner and arc-edge triangle rigid models to measure the surface wind pressure time histories of the single model and the parallel twin tower models.54 interference conditions including 9 layouts and 6 relative distances of twin towers are designed.The influences of interference effects on wind loads,wind-induced dynamic response and non-Gaussian characteristics of fluctuating wind pressure under different conditions are analyzed,results of which are compared with those of single tower condition.The paper studies the distribution characteristics of the mean wind pressure coefficient on surfaces,the variation law of the along-wind shape coefficient in different heights,and the self-power spectrum characteristics of fluctuating wind loads of the base in the along-wind,across-wind and torsional direction under various twin-tower conditions.Besides,the paper investigates the influences of interference effects on peak acceleration and peak displacement of the top floor,as well as the equivalent moment and shear of the base of the interfered building.Furthermore,the paper analyses and compares non-Gaussian characteristics of the fluctuating wind pressure of the interfered building under typical conditions,and separates Gaussian and non-Gaussian wind pressure zones accordingly.The paper then choose Sadek-Simiu method as the most reasonable method on calculating non-Gaussian peak factor to calculate the extreme wind pressure of the enclosure structure,giving the value suggestion.The main conclusions of this paper are as follows:(1)The influence of interference effects on the mean wind pressure on surfaces of the interfered building is generally unfavorable,increasing the mean wind pressure coefficient of local areas.When the relative spacing ratio of twin towers is no more than 3,the interference effect is the severest,and at the same time the mean wind pressure in the acrosswind direction is the most affected.(2)Generally speaking,the interference effects have little influence on the self-power spectrum of fluctuating wind loads of the interfered building’s base in along-wind,acrosswind and torsional direction.The along-wind spectrum is dominated by the low-frequency background component.While the across-wind peak energy may decrease greatly and the torsional energy tends to shift to low frequency.(3)The influence of interference effects on the dynamic response in the across-wind direction is more significant than that in the along-wind direction.When the relative spacing ratio of twin towers is no more than 3,the interference effect is the severest,where the interfered building generally reach the most unfavorable peak acceleration,peak displacement,equivalent base moment and equivalent base shear in the along-wind and across-wind direction.(4)Generally,the interference effects have a significant influence on the skewness and kurtosis of the wind pressure coefficient of the lee side and the rounded-corner area of the interfered building,but has little influence on the non-Gaussian and Gaussian zones of the wind pressure on all surfaces where the non-Gaussian wind pressure zone dominates.When the relative spacing ratio of twin towers is no more than 3,the interference has the severest effects on the extreme wind pressure of the rounded-corner area of the interfered building.