Study Of Wind Effects On Large-span Structures By Field Measurement And Wind Tunnel Test And Theoretical Analysis

With the development of science and technology and the utilizations of the new lightweight, high strength material, civil buildings have been built larger in span and taller in height. As a result, these buildings tend to be of more long-period and lighted damped and the sensitivity to dynamic excitations by wind has increased. It is thus necessary to investigate the wind effects on these area symbol buildings.The field measurements of wind characteristics and wind-induced responses of the Guangzhou International Convention&Exhibition Center (GICEC) were conducted with the real-time monitoring system of wind effect during the passage of Typhoon Nuri. The vibration modals were determined by means of peak picking method (PP), frequency domain decomposition method (FDD), and random decrement technique (RDT), and comparisons with those calculated from a finite element model of the structure was made to assess the accuracy of the numerical analysis method was made. The amplitude-dependent damping characteristics were discussed in detail by means of random decrement technique in frequency domain, and then the amplitude-dependent damping ratio characteristics were investigated. The characteristics of wind-induced pressures were analyzed in detail based on the synchronization multi-point pressure data measured in the wind tunnel tests. The wind-induced responses from full-scale measurements were compared with these from the wind tunnel tests results to examine the accuracy of the model tests results.The mechanisms of the axis of conical vortex and width of the conical vortex were analyzed in detail based on the synchronization multi-point pressure tests on a large span flat roof under six different approaching turbulence flows. The characteristics of the vortex shedding were estimated based on the spectra of fluctuating pressures, and the Non-Gaussian features were also evaluated with the probabilistic characteristics of the fluctuating pressures.Profiles of Mean wind speed and turbulence intensity of typhoon winds in surface boundary layer were determined based on wind data recorded from anemometers on a100-m meteorological tower under open terrain during land falling of typhoons. The wind filed of typhoon and that of terrain category B specified in the Chinese load code were accurately simulated in a boundary layer wind tunnel, respectively, and then the characteristics of wind loads on a large-span roof structure were analyzed based on a rigid model test resuluts of a large-span stadium structure. Furthermore, the discrepancies of wind loads affected on the structure under two wind fields were evaluated and discussed.Wind tunnel tests on two large-span hyperboloidal roof structures were conducted, and then the shape coefficients of them were studied in detail. The differences of the shape coefficients between the test results and those stipulated in China load code were made. A model test on a large-span station building was also conducted in wind tunnel over open terrain (terrain category B). Base on the tests data, the characteristics of wind-induce surface pressure were analyzed in detail. The influence to the surface pressure features by trains was discussed. And then the peak factors were determined by means of probability analysis.A wind field can be decomposed into principal coordinates only related to time domain and eigenvectors by means of proper orthogonal decomposition method (POD). The program composition with MATLAB for four space interpolation method, such as triangulation with linear interpolation, natural neighbor, inverse distance weighted method, and kriging method, were used for interpolation of the eigenvectors. The combinations of POD technique and space interpolation method were adopted to predict the surface wind pressures, and then the error levels for the four interpolation methods were estimated in time domain and frequency domain as well as by means of probability analysis, respectively. Finally, the program of combination of POD technique and CQC method and SRSS method to calculate the wind-induced responses was introduced.In this study, the combination of the field measurement, wind tunnel test, and theoretical analysis was adopted to investigate the wind effects on large-span structures. The results in this paper are expected to be of considerable interest and of use to researchers and professionals involved in desing large-span structures.