| With the characteristics of light weight,high flexible and lightly damped,high-rise buildings are prone to translational and torsional wind-induced response during the passage of typhoons.It is estimated that 94 tropic al cyclones landed in Hainan from 1964 to 2018.However,full-scale measurements on wind-field characteristics,translational and torsional wind-induced responses of high-rise buildings in the South China Sea during the passage of typhoons are still far fr om enough.Especially few full-scale measurements have been conducted to obtain wind-field characteristics and wind-induced responses of the same high-rise building for many years during typhoons with different inflow-wind directions.The measured high-rise building,with a height of 108 m,has 32 stories and is supported by giant space trusses with 4 huge columns.Wind-field characteristics,acceleration responses along translational and torsional directions are monitored synchronously and continuously during the passage of Typhoon Rammasun,Kalmaegi,Mujigae,Sarika and Khanun from 2014 to 2018.The characteristics of wind-field,translational and torsional wind-induced response are investigated.The amplitude-dependent modal damping ratios and frequencies along translational and torsional directions are investigated.Based on AR model,the linear filtering method is used to simulate the along-wind and cross-wind fluctuating wind characteristics of different floors along the height direction,the wind-induced response of longitudinal,lateral and tosional directions are calculated,and the influence of modal parameters on wind-induced response of the measured building are discussed.The following research results have been achieved in this paper:(1)Based on the wind-field measurements during five typhoons,the mean and fluctuating wind characteristics during the passage of typhoons are analyzed with a interval of 10 min.The main parameters including t urbulent intensity,turbulent integral scale,peak factor,gust factor,probability density function,fluctuating wind speed spectrum,etc.Meanwhile,the intrinsic correlations between these parameters and average wind speed as well as wind direction are investigated in detail.The effects of different terrain-types on turbulent intensity,turbulent integral scale and ratio of longitudinal and lateral turbulence intensities are systematically compared.The relationships between gust factor and sample durat ions and gust duration are revealed,and the empirical formula between gust factor and turbulence intensity is proposed.The PSD functions of along-wind and across-wind fluctuating wind during typhoons at different stages are investigated.(2)The time-history of torsional angular acceleration of four floors of the measured building is recorded by RA013 rotational accelerometer for the first time in China,and the translational acceleration of different floors is obtained by the translational accelerometer.Taking 10 min as the basic time interval,the variation trends of the root-mean-square of accelerations and peak values along both the longitudinal,lateral and tosional directions with floor height and mean wind speed are discussed.The frequency domain characteristics of translational acceleration and torsional angular acceleration of the measured floors during typhoons are analyzed.The Probability characteristics of translational acceleration and torsional angular acceleration of different floors are investigated.The total probability convergence method is adopted to calculate peak factors of the measured translational acceleration and torsional angular acceleration under different target guaranteed rates.The peak of acceleration self-power spectrum at the first mode at the first three modes of the high-rise building with respect to speed wind in different stages of typhoon landing is revealed.(3)Based on different identification results of modal parameters under different wind speeds,the amplitude-dependant translational and torsional modal parameters(mode shapes,damping ratio & frequency)under different wind speeds are identified.The measured results reveal that wind speeds and RMS of accelerations are correlated with the modal frequency,thus the estimation formula of fundamental frequency considering the influences of the wind speed and RMS of acceleration is proposed respectively.The field measurement data and statistical parameters provide useful information on the wind-resistant design of high-rise buildings in typhoon-prone regions.(4)The along-wind and cross-wind fluctuating wind loads of different floors along the height direction are simulated,the wind-induced response of longitudinal,lateral and tosional directions are calculated,and the results are compared with the measured wind-induced acceleration responses.The influence of modal parameters on wind-induced response of the measured building are discussed. |
