No abstract

In recent years, many large span roofs of airport waiting room and garage were destructed in the tropic storm, which have the characteristics of light mass, high flexibility, slight damping and low natural frequency. Wind loads general control the design of such structures. Thus, the tests of wind pressure with the rigid scale model in boundary layer wind tunnel were conducted in the structural design stage. This paper presents the results of characteristics of wind loads on large-span roof structure of the Guangzhou International Convention & Exhibition Center (GICEC) in frequency domain. The power spectrum densities, correlation coefficients, coherence functions and probability density function (PDF) were analyzed in detail. The results can be summarized as follows: (1)The power spectrum densities of fluctuating wind loads have the characteristics of vortex shedding and the Strouhal number is about 0.295; (2)The coherence coefficients decrease with the frequency and the spatial distance increase at both the along-wind and across-wind direction; (3)There are clearly negative skewed distributions for some pressure taps at the windward leading roof edge and much longer negative tails are observed, which follow Non-Gaussian distributions. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing complex long-span roof structures.

This paper presents some selected results obtained from the field measurements of wind effects on Guangzhou International Sports Arena (GISA) during the passage of Typhoon Fanapi in September, 2010. The field data such as wind speed, wind direction and acceleration responses, etc., were simultaneously and continuously recorded during the typhoon. The measured acceleration data are analyzed to obtain the information on dynamic characteristics and wind-induced response of the large-span roof structure. The first four natural frequencies and vibration mode shapes of the roof are identified on the basis of the field measurements using the stochastic subspace identification (SSI) method and comparisons with those calculated from the computational model of the roof are made. The damping ratios of the roof are also identified by the SSI method and compared with those estimated by the random decrement method, and the amplitude-dependent damping characteristics are presented and discussed. Furthermore, the field measurement results are compared with the wind tunnel test results to examine the accuracy of the model test results and the adequacy of the techniques used in wind tunnel tests.

Guangzhou West Tower (GZWT) is the second tallest building in China with 432m height. Based on the 3-D finite element model of this building, a reduced finite element model was first established for the wind-induced vibration analysis in the paper. Several models for the amplitude-dependent structural damping and aerodynamic damping ratio were adopted to evaluate the nonlinear damping effects on the wind-induced response of this building by using the surface wind pressure record in wind tunnel test. Wind-induced responses evaluated by amplitude-dependent damping were compared with those obtained from constant damping ratio assumption through the comprehensive studies for several wind load cases.