Investigation Of Characteristics Of Wind Load On Double Slope Station And Wind Environment Of Platform

As the span and scale of the building increased,large span roof structure with light dead weight,low stiffness and low damping becomes more and more popular.But at the same time,the long-span roof structure is sensitive to wind load,so wind tunnel experiment and CFD simulation research are very important.Taking a large span double slope roof structure as an example,the wind tunnel experiment of rigid model was carried out,and the wind load characteristics of its roof were studied.By comparing the results of CFD simulation with wind tunnel experiment,the correctness of numerical simulation was verified.Then,according to the flow field simulated by CFD,the wind environment of the platform was evaluated.The main research contents are as follows:（1）The boundary layer of the wind tunnel experiment was type B area.The experiment wind direction was set every 10°to collect wind pressure data ranging from 0°to 360°.After processing the data,the mean wind pressure coefficient contour map and the fluctuating wind pressure contour map under four typical wind direction angles were given,then,the distribution rule of the contour map was analyzed.（2）By analyzing the fluctuating wind pressure signals of the roof,it was found that the regions where the air separation occurs,such as the leading edge area of the windward side,the edge area of the roof and the high slope of the roof,had obvious non-Gaussian characteristics.According to the correlation coefficient of measuring points,the cause of non-Gaussian characteristics of fluctuating wind pressure was preliminarily discussed.The contour maps of skewness value（λ₃）and kurtosis value（λ₄）of wind pressure time history at four typical wind direction angles were given.（3）When the cumulative probability of|λ₃|and|λ₄-3|of wind pressure signal reaches 80%respectively,the critical skewness and kurtosis values were taken as the criteria for dividing Gaussian area and non-Gaussian area of roof.Then,based on the skewness value and kurtosis value of wind pressure time history,the non-Gaussian process was converted into the Hermite series of Gaussian process,and the peak factors of typical measuring points under four wind direction angles were obtained,which were obviously higher than the recommended values in the specification.（4）By comparing the CFD simulation with the wind tunnel experiment results,the correctness of the numerical simulation was verified.In addition,a large average wind pressure coefficient was found at the roof overhang in the CFD simulation,which should be strengthened against wind.Taking the wind speed and wind speed ratio at the pedestrian height of 1.5 m as the wind environment assessment criteria,combined with the flow chart of the flow field,the comprehensive analysis showed that the wind environment in the area between the inside of the column foot of the station and the outer wall of the main station as well as the station platform needed to be improved.