Field Measurement Research On Wind Characteristics And Wind-induced Response Of High-rise Buildings Under Typhoon

Due to the novel structure and increasingly complex shape of high-rise buildings,their characteristics of light weight,high flexibility,and low damping lead to prominent wind-induced response problems.In recent years,the number of landing typhoon in Zhejiang and Fujian has become more and more frequent.Yet,the research about the wind characteristics,wind pressure,and wind-induced response in this area is far from enough,especially the measured research for high-rise building torsion effect induced by typhoons.Furthermore,synchronization measured researches for the wind characteristics,wind pressure,and wind-induced response for a long time in the same building both at home and abroad are very scarce.In this paper,a wind resistance measurement base was established,relying on three high-rise buildings in Xiamen and a high-rise building in Wenzhou.The synchronous measurement research on wind field,wind pressure,horizontal acceleration response,and torsional acceleration response for Typhoon "Matmo","Fung-Wong","Chan-Hom","Dujuan","Soudelor","Nepartak","Meranti","Megi","Talim",and "Maria" was conducted from 2014 to 2018,respectively.The main conclusions are as follows:(1)Based on the measured data of the typhoon wind field,the characteristics of mean wind and fluctuating wind at the top of the building were analyzed,including turbidity,gust factor,turbulence integral scale,and wind speed spectrum.The wind field data at the tops of three buildings in Xiamen under the influence of Typhoon Meranti was recorded.The relationships both among the fluctuating parameters and between the fluctuating parameters and the duration of gusts were discussed.The correlation of wind turbulence at the top of the three buildings was analyzed.The wind field data at the top of buildings in Wenzhou under influence of Typhoon Matmo was recorded,and the wind characteristics at different time intervals were discussed.The differences between Xiamen and Wenzhou wind characteristics were discussed.The results showed that the test building of Wenzhou is located in typical urban landscape,and its wind characteristics are more pulsating.(2)Based on the measured data of the typhoon wind pressure,the fluctuation characteristics of wind pressure,including wind pressure coefficient,probability of fluctuating wind pressure,peak factor,and correlation of fluctuating wind pressure,were analyzed.The differences of wind pressure characteristics between Xiamen and Wenzhou were discussed.The results showed that the difference among the subsamples was small when the data with relatively stable incoming flow direction was selected for analysis.The time history of the pressure coefficient on the windward side was similar and the peak value was larger,while the peak value of the pressure coefficient on the leeward and crosswind side was smaller.Fluctuating wind pressure at each measuring point did not meet the Gaussian distribution characteristics.Under the same target guarantee rate,the measured peak factor was greater than the corresponding code value.(3)Wind-induced torsion response was measured and studied using the torsional acceleration sensor RA013 for the first time.Type 991 C sensor was used to record the horizontal acceleration response under the effect of the typhoon.The Gaussian characters of horizontal acceleration and torsional acceleration responses were analyzed based on the measured accelerations of several floors.The results showed that the wind direction of typhoon has great influence on the Gaussian characteristic of the horizontal acceleration response,while the Gaussian characteristic of the torsional acceleration is related to the mean wind speed.Based on the target guarantee rate,the value ranges of peak factors in horizontal and torsional accelerations were proposed.Under the same target guarantee rate,the code value based on Gaussian characteristic is low.The relationship between root mean square of acceleration and mean wind speed was discussed.The peak value and RMS of acceleration response increase with the increase of wind speed under typhoon.When the amplitude of mean wind speed and acceleration is larger,the exponential relationship between acceleration response and mean wind speed is more obvious.(4)Based on the measured horizontal acceleration response and torsional acceleration response,horizontal and torsional modal parameters of the structure were identified via method of Welch and improved ERA-NEx T.The relationships both between natural frequency and mean wind speed and between structural damping ratio and root mean square acceleration were discussed,which provides a reference for studying the dynamic characteristics of high-rise buildings under the effect of the typhoon.