Search

Highlights • A Kalman filter based inverse method for wind force identification is developed. • The method allows simultaneous estimation of wind loads and structural responses based on limited responses. • The feasibility of the method is evaluated based on wind tunnel test results and filed measurements. • The validations show the method can accurately predict wind loads on tall buildings. Abstract An inverse method based on the discrete time Kalman filter is developed to simultaneously estimate the unknown wind-induced responses and wind loads of high-rise buildings using limited response measurements. The accuracy and effectiveness of the presented estimation method are assessed based on both wind tunnel test results and field measurements of wind effects on a super-tall building. The wind-induced responses obtained by wind tunnel test are used to identify the wind loads on the super-tall building and evaluate the effects of crucial factors, such as covariance matrix of noise, initial estimation error, noise in measurements, modelling errors of structural dynamic properties and number of vibration modes, on the identification results. In addition, the wind loads are also estimated based on the field measured displacements during Typhoon Neoguri. Comparisons between the identified wind loads from the field measured displacements and the wind tunnel test results are made to verify the applicability of the inverse technique. The results of this study illustrate that the proposed inverse method is an efficient tool for predicting the wind loads on super-tall buildings from limited measurements of structural responses. [ABSTRACT FROM AUTHOR]

This article presents a Kalman-filter-based estimation algorithm for identification of wind loads on a super-tall building using limited structural responses. In practice, acceleration responses are most convenient to be measured among wind-induced dynamic responses of structures. The proposed inverse method allows estimating the unknown wind loads and structural responses of a super-tall building using limited acceleration measurements. Taipei 101 Tower is a super-tall building with 101 stories and a height of 508 m. Field measurements and numerical simulations of the wind effects on Taipei 101 Tower are conducted. The wind loads acting on the super-tall building are estimated based on the windinduced responses determined from the numerical simulations and the refined finite-element model of the structure, which are in good agreement with the exact results. The stability performance of the proposed algorithm is evaluated. The influence of noise levels in the measurements and covariance matrix of noise on the identification accuracy are investigated and discussed based on the L-curve method. Finally, the wind loads and structural responses are reconstructed based on the field-measured accelerations during Typhoon Matsa. The accuracy of the identified results is verified by comparing the reconstructed acceleration responses with the field measurements. The results of this study show that the proposed inverse approach can provide accurate predictions of the wind loads and wind-induced responses of super-tall buildings based on limited measured responses. [ABSTRACT FROM AUTHOR]

Abstract: This paper is concerned with vertical distributions of mean wind speed and atmospheric turbulence characteristics over a typical urban area. The wind data were measured from more than 30 anemometers installed at 15 different height levels on the 325m high Beijing Meteorological Tower during numerous windstorms. Profiles of mean wind speed are presented based on the field measurements and are compared with empirical models’ predictions. Aerodynamic parameters of atmospheric boundary layer are determined from the measured wind speed profiles. Furthermore, wind velocity data in longitudinal, lateral and vertical directions, which were recorded by ultrasonic anemometers at three height levels during windstorms, are analyzed and discussed. Atmospheric turbulence information such as turbulence intensity, gust factor, turbulence integral length scale and power spectral densities of the three-dimensional fluctuating wind velocity are presented and used to evaluate the adequacy of the existing theoretical and empirical models. A comparative study between the measured profiles of turbulence parameters and those estimated by and is performed. The objective of this study aims to provide useful information on boundary layer wind characteristics for the wind-resistant design of tall buildings and high-rise structures in urban areas. [Copyright &y& Elsevier]

A new inflow turbulence generator was applied to simulate three kinds of inflow boundary conditions of turbulent flow field. A new one-equation dynamic subgrid scale (SGS) model was adopted for the present full-scale size large eddy simulations with extremely high Reynolds numbers (10 x 108). The mean pressures, fluctuating pressures and time-histories of the wind forces on the surface of Shenzhen Pingan IFC in the three flow field conditions were calculated based upon the paralleled technology of Fluent 6. 3 software platform under the Linux system. The equivalent static wind loads and wind-induced responses were obtained by the IWL method in frequency domain analysis. The effects of different turbulent flow fields on the wind pressure coefficients, wind forces and wind-induced response were discussed. The wind fields around the Shenzhen Pingan IFC are significantly different under the uniform and turbulence approaching wind flows. The along-wind loads are mainly dependent on the mean wind velocity. The across-wind loads increase with the increase of the turbulence intensity of approaching wind flow. In terms of the turbulence flow defined by Chinese code, the along and cross wind peak accelerations under 10 years return period at the top floor of the Shenzhen Pingan IFC satisfy the comfort requirement for the occupant. [ABSTRACT FROM AUTHOR]