Designing Refinement Of Wind Pressure On Glass Curtain Wall Of High-rise Building

Glass curtain wall has become the mainstream envelope structure of highrise buildings due to its many advantages including well lighting,lightness,beautiful appearance and small space occupation and convenient installation.As the world’s largest country of production and use of glass curtain wall,China has high requirements for wind resistance and cost control of glass curtain wall.The design wind pressure,which is the controlling load of the glass curtain wall of high-rise building,directly determines the safety and economy of the curtain wall design.However,there are some deficiencies in the load code of our country on the design wind pressure of building envelope.In view of these deficiencies,it is necessary to put forward suggestions for improvement based on the study and analysis of measured data,so as to provide a basis for the reasonable determination of wind load in the design of glass curtain wall.This paper mainly carries out research from the following aspects:The determination of the basic wind speed does not take the wind direction effect into account,so it is conservative to a certain extent.For this,the wind speed and direction distribution characteristics were studied based on the daily wind speed observation data of six major cities in China.The classical extremum theory and the transcendence threshold theory were used to carry out extremum analysis on the wind speed of each direction.The results show that the threeparameter Weibull distribution is better than the Gumbel distribution in most wind directions,the POT method based on small sample size underestimates the wind speed of some wind directions of typhoon affected cities.The improved Cook method and POT-Copula method were used to calculate the extreme wind speed of each direction considering the correlation of wind direction for a given return period.Combined with the wind direction frequency,the wind direction reduction factors of wind speed for each city were obtained.As there is some underestimation of the local non-gaussian wind pressure on the building surface in the design wind pressure of envelope structure stipulated in the code,the distribution of non-Gaussian wind pressure on high-rise buildings is studied based on the wind tunnel test data.The distribution of skewness and kurtosis of sampling data shows that the non-Gaussian wind pressure is closely related to the flow around the blunt body.In order to obtain more accurate wind pressure extrema based on finite time-length sampling data,five non-Gaussian time-history peak factor calculation methods are compared,and the results show that Johnson transformation method is the best method.The distribution of wind pressure on the crosswind side and leeward side of buildings with different shapes is studied.According to the results,the most adverse wind pressure is located in the middle and lower part of the facade.The building height has little influence on the extreme wind pressure distribution of the square column’s crosswind side,while the wind pressure distribution of the rectangular building’s facades with different aspect ratios has great difference.The wind direction reduction factor of wind load considering the building shape and orientation under different wind environments is further calculated.Based on the extreme wind pressure distribution of buildings of different shapes,the fine partitioning of local shape coefficients considering non-Gaussian characteristics was completed.The finite element model of the hidden frame glass curtain wall panel was established.Through parameter sensitivity analysis,it was found that the variation of parameters such as glass thickness and elastic modulus of silicone glue had great influence on the deflection response of the model.Based on the sampling time history of wind tunnel test,the maximum deflection response time history of each working condition model was obtained,and the corresponding failure probability was calculated.The results show that the external wind pressure of the envelope based on the local shape coefficient considering nonGaussian characteristics can satisfy the safety of the glass curtain wall under nonGaussian wind pressure.