Study On Wind Load Characteristics On Facades Of Rectangular High-rise Buildings With Different Corner Cuts

Based on a wind tunnel test,the wind load distribution characteristics on the facade of high-rise building with different corner cuts are studied in this paper.The distribution characteristics of wind pressure is discussed in both horizontal and vertical direction.A discriminant method of multi-sample fusion is proposed.The Non-gaussian characteristics of fluctuating wind load on different sections and peak factors of typical taps are analyzed in detail.Combining with practical engineering cases,this paper makes a detailed comparative analysis of the relevant provisions on wind load of facades and summarizes the similarities and differences between the codes of China and the United States.It can provide reference for relevant researchers or designers.The wind tunnel test data of the rectangular high-rise building with different corner cuts is compared with the CAARC model and code values.It is found that setting shallow grooves at the corner of rectangular section can weaken the positive wind pressure of the whole upwind wall obviously.And grooves can reduce the difference of wind pressure between the corner and the middle of the negative pressure area,which is beneficial to the facade structure.In the height direction,the trend of negative wind pressure along the upwind side is different from the exponential trend of the code,and the most dangerous cross-section of the wind-resistant design is at 1/3～ 2/3 building height.At the same time,the norm value can not completely envelop the negative pressure extreme value of the taps in the wall area in wind tunnel test.It is necessary to properly improve the shape coefficient of negative pressure of the wall area.The negative pressure at the corner of the windward side and the leeward side increases obviously with the "L" angle,and the wind pressure increases obviously at the positive angle with the increase of the depth of the "L" angle.The code value can not completely envelop the wind pressure of all the corner taps,which may lead to potential safety hazards.For the cross section,it is found that the local concave distortion is beneficial to weaken the wind pressure of the cross section.For the symmetrical taps,when analyzing their Non-gaussian characteristics in different methods,it is found that the third and fourth statistics are unstable,so only a single sample will lead to a misjudgment of the Gaussian characteristics.A method of discriminating the Gauss characteristic by fusing the data of different wind directions is proposed,which can improve the accuracy of discriminating.After fusion discrimination,it is found that shallow grooves at the corner have no significant effect on the Non-gaussian characteristics of rectangular section.But for rectangular section with L-shaped corner cuts,the Non-gaussian distribution of fluctuating wind pressure is obviously affected by the depth of corner cuts.When the corner cuts are small,the Non-gaussian area on the windward side is pushed to the trailing edge,and the overall Gaussian property of the cross-section is better.When the corner cuts are large,the positive angle taps show very obvious Non-gaussian characteristics at all wind directions.The Non-gaussian characteristic of cross section of the positive angle taps is obvious.Generally,the Gaussian characteristic of negative angle taps is better than that of positive angle taps,which should be treated differently in the building facade structural design.It is found that the peak factors calculated by single sample are also unstable.For symmetrical structure,it is suggested to fuse multiple samples to calculate the peak factor.The peak factors of corner,groove and corner cuts are larger than that of wall area.Thus,it is suggested to increase the peak factors of corner.