Experimental Study On Wind Load Characteristics Of Tall Buildings With Opening

With the improvement of design and construction level,numerous tall buildings have been springing up on the ground and wind loads gradually become the main control load.In order to satisfy the demand for structural and aesthetic function,opening in tall buildings has become a common The wind load calculation of tall buildings with openings is more complicated,and there is no clear design basis.To study the effects of opening locations,opening rates,side ratios,terrain categories and opening forms on wind load of tall buildings,B、C and D terrain categories were simulated in boundary layer wind tunnel,series of plain models and opening models with different structural sizes were tested by synchronous pressure measurement technology in this paper.The main work of this paper is the following:(1)Study on wind load amplitude characteristics of tall buildings with openings: The effects of factors such as opening rate,side ratio and terrain category on the wind load amplitude characteristics of tall buildings were studied from the aspects of mean and RMS wind pressure coefficient,local wind force coefficient and base moment coefficient.(2)Study on frequency domain characteristics of wind loads in tall buildings with openings: The effects of factors such as opening rate,side ratio and terrain category on the frequency domain characteristics of wind loads of tall buildings were studied from the aspects of power spectrum,correlation and coherence functionThe results are as follows.1)After opening on the tall building,the mean wind pressure coefficient in the area near the opening on the windward surface reduces,while the RMS wind pressure coefficient in that increases;the RMS wind pressure coefficient and the absolute value of mean wind pressure coefficient decrease as a whole on the leeward surface;The local mean and RMS drag coefficient in the opening level decreases significantly,and the mean base moment coefficient in the along-wind direction decreases.In the opening level,the peak value and low-frequency energy of the local lift spectrum decrease,and the local torque power spectrum shows broadband characteristics.The correlation coefficient of the local wind force between cross direction and torsional direction decreases significantly.2)Opening in the upper of building is more conducive to reducing the wind load on tall buildings.3)With the increase of the opening rate,the local mean drag coefficient and RMS drag coefficient of the opening level decrease significantly.The cross-torsional correlation both local wind force and base moment decreases gradually.4)As the side ratio increases,the mean along-wind force increases first and then decreases;the RMS along-wind force decreases gradually,the local RMS crosswind force increases gradually,and the RMS torque decreases first and then increases.The cross-torsional correlation both local wind force and base moment decreases.5)Compared with the models which opening in the front and back faces,the mean along-wind force,the RMS along-wind force and the RMS cross-wind force of the models which opening in all faces are reduced.6)From B to D terrain categories,the mean along-wind force decreases gradually,while the RMS along-wind force increases gradually.The local RMS lift coefficient on the upper part of models increase gradually;and the RMS torque increased slightly.The crosstorsional correlation coefficient of base moment decreases gradually.7)The formulas for calculating the base moment coefficients in along-wind,cross-wind and torsional direction variation with the opening position,opening rate and side ratio are fitted.