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Wind resistance is one of the most important safety targets for high-rise buildings, especially slab-shaped ones with relatively large length–width ratios. In this study, the characteristics of wind pressure on a reduced-scale model of a slab-shaped high-rise building were analyzed experimentally. The experiment was conducted using the DTC Initium electronic scanning pressure measurement system in the wind tunnel at the Xiamen University of Technology, China. The spatial distribution and time-frequency characteristics of the wind pressure signals were analyzed with various wind flow directions under uniform and boundary-layer inflow conditions. The results show that both of the inflow conditions and the wind directions have significant influences on the magnitude and distribution characteristics of the wind pressure on the building surfaces. The wavelet transform-based analysis shows that the wind pressure on the building surfaces presents obvious intermittent characteristics, with the instantaneous energies pulsating intensively in the time-frequency domain, illustrating the unsteady nature of the wind pressure loads on the building. The influence and risk of the unsteady pulsating pressure loads should be considered when evaluating the wind-resistant performances of this type of building. [ABSTRACT FROM AUTHOR]

The rainy and windy weather conditions during the passage of tropical cyclone (TC) usually cause large-amplitude rain-wind induced vibration (RWIV) of stay cables in bridges, threatening the fatigue life of stay cables and even the safety of bridge structures. In this study, the probability analysis of RWIV of stay cables under TC-induced wind and rainfall environment is performed using both wind tunnel test and numerical simulation techniques. RWIV amplitudes associated with various combinations of wind speed and rainfall rate are obtained by wind tunnel test on a prototypic sectional cable model. Surrogate models including polynomial and Kriging methods are introduced to fit the experiment results, allowing for the construction of three-dimensional surface representing RWIV amplitude or the capacity of the stay cable. A case study is performed to the Jintang Cable-stayed Bridge located at the southeast coast of China. Ten-thousand-year synthetic TC tracks around the bridge site are then generated by Monte Carlo technique. Subsequently, wind speeds and rainfall rates at the bridge site for every storm are calculated using the three-dimensional TC wind field model and HuRRDE (Hurricane Rainfall Rate and Distribution Estimator) model, achieving the joint probability distribution of wind speed, wind direction and rainfall rate. The occurrence probabilities of various RWIV amplitudes during TC process are finally calculated to conduct the probability analysis. The framework and results in this study can be utilized as a guideline and reference for the design and early warning of stay cables against RWIV. • Fragility analysis for RWIV of stay cables under TC-induced wind and rainfall environment is performed. • Joint probability distribution of wind speed and rainfall rate is achieved using Monte Carlo technique. • Surrogate models of RWIV amplitudes are developed by fitting experiment results. • A case study is applied to a cable-stayed bridge located at the southeast coast of China. [ABSTRACT FROM AUTHOR]

This study presents an investigation to quantify the aerodynamics of truss bridge-girders via wind tunnel test and kriging surrogate model. Currently, the conventional methods documented in design specifications only take into consideration the mean drag force at null attack angle. To gain an in-depth understanding on the aerodynamics of truss bridge-girders, experiments on simplified bridge-girder models with various geometric parameters were carried out in uniform flow. A total of 15 truss bridge-girder models with aspect ratio (the ratio of width to height) B/D = 1.0, 1.3, 1.6, 1.9, and 2.2, solidity ratio (the ratio of projected to envelope areas) Φ = 0.20, 0.25, 0.30, 0.35, and 0.40, and two typical truss topologies (Warren and Pratt trusses) were examined in the most concerned range of wind angle of attack α = [–6°, 6°]. These truss bridge-girder models cover most of the high-speed railway bridges widely used in China. Experimental results show that the truss topology has limited effects on the aerodynamics of truss bridge-girders, whereas the effects of α, B/D, and Φ are significant. Based on these wind tunnel results, the ordinary kriging surrogate model was utilized to approximate the aerodynamics of truss bridge-girders. In using this model, aerodynamic force values for test cases can be interpolated with zero variance and uncertainties in unsampled design zones where geometric parameters can be quantified with Gaussian variance. [ABSTRACT FROM AUTHOR]

The serviceability of super-tall buildings depends primarily on the wind-induced structural responses, especially accelerations. To mitigate the discomforting structural vibrations, pendulum-type tuned mass damper (TMD) systems are commonly employed in high-rise buildings. However, for a super-tall building with a considerably low fundamental natural frequency, the suspension length of a pendulum-suspended TMD (PTMD) becomes too long to be feasible as it would occupy substantial building space. For the sake of saving valuable space in a super-tall building, a multistage PTMD system is recommended for vibration control. This paper presents a detailed assessment study on the performance of a multistage PTMD system designed for a 600 m high skyscraper located in a typhoon-prone region in China. Wind tunnel tests are first conducted to determine the wind loads on the building for estimation of structural dynamic responses for the scenarios with and without installation of the multistage PTMD system. Optimal design of the multistage PTMD system is then carried out through examining the mitigation efficiency of the PTMD system for a variety of mass and damping ratios. To restrict the strokes of mass dampers in the PTMD system, two-section damping strategy is proposed. The assessment results demonstrate that the multistage PTMD system with two-section damping can function efficiently to suppress the excessive vibrations of the skyscraper, while occupying a minimal space in vertical and horizontal directions. This paper aims to provide an effective and economic design strategy for vibration control of super-tall buildings under wind excitations. [ABSTRACT FROM AUTHOR]

The Maanshan Bridge over Yangtze River in China is a new long-span suspension bridge with double main spans of 2 x 1080 m and a closed streamline cross-section of single box deck. The flutter and buffeting performances were investigated via wind tunnel tests of a full bridge aeroelastic model at a geometric scale of 1:211. The tests were conducted in both smooth wind and simulated boundary layer wind fields. Emphasis is placed on studying the interference effect of adjacent span via installing a wind deflector and a wind separating board to shelter one span of the bridge model from incoming flow. Issues related to effects of mid-tower stiffness and deck supporting conditions are also discussed. The testing results show that flutter critical wind velocities in smooth flow, with a wind deflector, are remarkably lower than those without. In turbulent wind, torsional and vertical standard deviations for the deck responses at midspan in testing cases without wind deflector are generally less than those at the midspan exposed to wind in testing cases with wind deflector, respectively. When double main spans are exposed to turbulent wind, the existence of either span is a mass damper to the other. Furthermore, both effects of mid-tower stiffness and deck supporting conditions at the middle tower on the flutter and buffeting performances of the Maanshan Bridge are unremarkable. [ABSTRACT FROM AUTHOR]

With the rapid increase in China's development, the cities have become immensely more dense putting pressure on design and infrastructure. In the past, most of the China's buildings imitated the foreign architectural styles and had a lack of scientific and meaningful design. These buildings became to be known as the 'the cheap copy buildings'. The primary cause was the shortage of proper technology, such as building wind tunnel test equipment. Therefore, scientific design was not always an option, only reversal or empirical design could be utilized. This meant architects were restricted to construct the same design or imitate foreign buildings. Now that China has access to wind tunnels, building designs can be analysed at a higher level. Forward and scientific designs can be used to improve the buildings' capabilities with low cost. [ABSTRACT FROM AUTHOR]

Based on field measurements and wind tunnel test for wind pressure along the surface of a super-tall building on the coast of Xiamen city, this paper presented some important characteristics and distribution regularities of measured instantaneous wind pressure, mean wind pressure, mean wind pressure coefficients and fluctuating pressure coefficients on super-tall building during passage of typhoon Fanabi. The results clearly demonstrate that the mean wind pressure characteristics and its distribution regularities on super-tall building revealed by field measurements are roughly agree with the correponding results of wind tunnel test; the mean wind pressure coefficient results of field measurements is obvious larger than that of wind tunnel test on the windward side, nevertheles, the difference between the mean wind pressure coefficients of field measurements and that of wind tunnel test on other sides is relative small. [ABSTRACT FROM AUTHOR]

Wind tunnel test on mitigation of wind induced response (WIR) of the Shenzhen Kingkey Finance Tower (KFT) was conducted using aero-elastic model technique in the boundary layer wind tunnel. A cantilever device arranged in the top-level of the model of KFT was designed to evaluate the effectiveness of tuned mass damper (TMD) for suppressing cross WIR of KFT. The effect of different parameters of TMD on the mitigation of WIR was researched in the test, and the results of aero-elastic model were compared with those of the numerical calculation in which the rigid building model based high frequency pressure integration ( HFPI) was applied to calculate the WIR of the building. The results show that the maximum reduction of WIR is achieved when the frequency of TMD is close to the fundamental frequency of the structure, where the optimal TMD frequency is slightly less than the frequency of the structure due to the existing structure damping. The maximum reductions of acceleration response of top story of the two TMD damping ratios of 3. 83% and 1. 67% are 20% and 15% respectively. However, WIR may keep unchanged when TMD damping ratio is less than or equal to 0. 07%. [ABSTRACT FROM AUTHOR]

Wind tunnel tests of wind loads acting on the roof of Shenzhen new railway station were conducted in a boundary layer wind tunnel at Hunan University, for the conditions without train and with trains inside the station. In addition, the effects of wind speed amplify in the station were also investigated. This paper presents the results of the mean and RMS wind pressure coefficients, and comparisons of the maximum mean negative wind pressure coefficients and fluctuating wind pressure coefficients for the case of without train and with trains were made. Furthermore, the characteristics of probability density functions of wind pressures measured from typical pressure taps were analyzed, and the peak factors of that were estimated under a probability significance level of 99.999%. On the other hand, the results obtained from numerical simulations were also presented in the paper, and the results were compared with the wind tunnel test data. The outcomes of the combined experimental and numerical study indicate that: (1) The maximum mean negative wind pressure coefficients on the roof occur at the windward leading edge region, where the maximum fluctuating wind pressure coefficients occur also in this region; (2) There are some differences of the maximum mean negative wind pressure coefficients and RMS wind pressure coefficients under conditions with different number of trains inside the station, but such effects on the overall pressure distributions on the whole roof are negligible; (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; (4) Wind flow was found to be congregated inside the holes at the structure, and the maximum wind speed amplify coefficient is up to 1.34; And (5) the results obtained from the numerical simulations are in good agreement with these of the wind tunnel test, illustrating that the Large Eddy Simulation (LES) approach and Discretizing and Synthesizing Random Flow Generation (DSRFG) technique are effective tools for numerical simulations of wind effects on the complex long-span roof structures. [ABSTRACT FROM AUTHOR]

This paper presents work on validating the dynamic wind load predicted by a wind tunnel model with the values identified from full-scale field vibration data of a super-tall building in Hong Kong. Dynamic wind load in this work refers to the power spectral density (PSD) of the modal force near the natural frequency of a particular mode of the building, in the context of random vibration with stationary loading and response. This quantity reflects the turbulence characteristics integrated over the building body and is of importance in wind engineering design. This study presents a method to predict the modal PSD of wind load of the first two translational modes of a tall building. The method combines wind tunnel test information and mean wind data available in the free field; the latter taken to be at the Waglan Island station maintained by the Hong Kong Observatory. On the full-scale side, although the modal PSD is not directly observable, it is identified from field vibration data measured at the building top during strong wind events. A Bayesian modal identification method is used for determining the most probable value and the uncertainty of the modal parameters including the natural frequency, damping ratio, and the modal PSD. A number of recent strong wind events are analyzed. Reasonable agreement is observed between the wind tunnel model predictions and the values identified from field data. Factors that can potentially lead to discrepancy are discussed. As the same random vibration modeling consistent with conventional wind engineering design has been used in the wind tunnel prediction model and field identification model, the results are directly transferable among these three disciplines. [ABSTRACT FROM AUTHOR]

On the April 9 of 2000, a gigantic rapid rock slide-debris avalanche occurred in Bomi, Tibet. Some 280-300 × 10 m of material travelled 10 km within 10 min and dammed the Yigong River, forming a 2.9 × 10 m³ barrier lake. Wind tunnel testing was undertaken to determine the aerodynamic parameters involved, from the initial rock slide-fall to its point of impact. The paper reports the numerical analyses undertaken and discusses the significance of the air-cushion effect. It is concluded that Yigong rapid rock slide-debris avalanche 'flew' in the air for about 12.9 s from its detachment from the source to its collision with the floor of the Zamunong gully at 3,317 m asl. The velocity of the avalanche mass at the point of detachment was some 81.8 m/s and the collision velocity approximately 117 m/s. [ABSTRACT FROM AUTHOR]

Based on the field measurement and wind tunnel test for wind pressure on the surface of a super-tall building on the coast of Xiamen city, this paper discussed the wind pressure characteristics and its distribution on super-tall building during the passage of typhoon Megi. The results clearly demonstrate that the wind pressure characteristics ( mean wind pressure coefficient and extreme wind pressure coefficient) and its distribution on super-tall building revealed by wind tunnel test are roughly agree with the field measurement. The mean wind pressure coefficient results of field measurement fit with wind tunnel test very well on the windward side, while the value of field measurement is smaller than wind tunnel test on the leeward side obviously. There is a relative large difference in extreme wind pressure coefficient results between wind tunnel test and the field measurement except for some single test point. [ABSTRACT FROM AUTHOR]

The full-scale measurements are compared with the wind tunnel test results for the long-span roof latticed spatial structure of Shenzhen Citizen Center. A direct comparison of model testing results to full-scale measurements is always desirable, not only in validating the experimental data and methods but also in providing better understanding of the physics such as Reynolds numbers and scale effects. Since the quantity and location of full-scale measurements points are different from those of the wind tunnel tests taps, the weighted proper orthogonal decomposition technique is applied to the wind pressure data obtained from the wind tunnel tests to generate a time history of wind load vector, then loads acted on all the internal nodes are obtained by interpolation technique. The nodal mean wind pressure coefficients, root-mean-square of wind pressure coefficients and wind pressure power spectrum are also calculated. The time and frequency domain characteristics of full-scale measurements wind load are analyzed based on filtered data-acquisitions. In the analysis, special attention is paid to the distributions of the mean wind pressure coefficients of center part of Shenzhen Citizen Center long-span roof spatial latticed structure. Furthermore, a brief discussion about difference between the wind pressure power spectrum from the wind tunnel experiments and that from the full-scale in-site measurements is compared. The result is important fundament of wind-induced dynamic response of long-span spatial latticed structures. [ABSTRACT FROM AUTHOR]

This paper presents the field measurement results of wind effects on a super-tall building (CITIC Plaza, 391 m high) located in Guangzhou. The field data such as wind speed, wind direction and acceleration responses were simultaneously and continuously recorded from the tall building by a wind and vibration monitoring system during two typhoons. The typhoon-generated wind characteristics including turbulence intensity, gust factor, peak factor, turbulence integral length scale and power spectral density of fluctuating wind speed were presented and discussed. The dynamic characteristics of the tall building were determined based on the field measurements and compared with those calculated from a 3D finite element model of the building. The measured natural frequencies of the two fundamental sway modes of the building were found to be larger than those calculated. The damping ratios of the building were evaluated by the random decrement technique, which demonstrated amplitude-dependent characteristics. The field measured acceleration responses were compared with wind tunnel test results, which were found to be consistent with the model test data. Finally, the serviceability performance of the super-tall building was assessed based on the field measurement results. [ABSTRACT FROM AUTHOR]

We carried out a wind tunnel test to measure cladding loads for a high-rise building of 295 m in height, which would be located in the business center of Chongqing Municipality, P. R. China. The rigid model was used to determine fluctuating local pressures on the exterior surfaces of the building. The wind tunnel test results show the critical zone of wind pressures on building surfaces in both standalone and interference conditions. The computational fluid dynamics (CFD) was conducted by using the FLUENT Code to compare with the wind tunnel test results, and the steady three-dimensional turbulent flow with Realizable k-ε as a turbulence model was used. The CFD results are agree with the wind tunnel test results in regards to distributions of wind pressures over a high-rise building’s surfaces. [ABSTRACT FROM AUTHOR]

Abstract: The Jin Mao Building located in Pudong New Area, Shanghai, which has a height of 420.5m and 88 floors, is currently the tallest building in Mainland China. This paper presents some selected results obtained from the full-scale measurements of wind effects on the Jin Mao Building during the passage of Typhoon Rananim in August, 2004. The field data including acceleration responses, wind speed and wind direction were simultaneously and continuously recorded during Typhoon Rananim. Detailed analysis of the field data was conducted to investigate wind effects on the super tall building. The characteristics of typhoon-generated wind and wind-induced responses of the 88-storey building are presented and discussed. Dynamic properties of the building are determined based on the field measurements, and comparison with those calculated from the finite element model of the building is made. The amplitude-dependent characteristics of damping that were obtained using the random decrement technique on the basis of the field measurements are investigated. Furthermore, wind tunnel experiment is conducted to study wind effects on the Jin Mao Building through force balance model test, and the full-scale measurements are compared with the wind tunnel test results for verification of wind tunnel test techniques. Finally, the serviceability of the super tall building under typhoon conditions is discussed. [Copyright &y& Elsevier]

Abstract: The Jin Mao Building with a height of 420.5 m and 88-storeys, located in Shanghai, is the highest tall building in Mainland China. This paper presents selected results from a combined wind tunnel and full-scale study of wind effects on the super tall building. In the wind tunnel test, mean and fluctuating force components on the building model for the cases of an isolated Jin Mao Building and the building with existing surrounding condition were measured by a high-frequency force balance technique under suburban and urban boundary layer wind flow configurations, respectively. Force coefficients, power spectral densities, displacement and acceleration responses were then presented and discussed. A detailed comparative study was conducted to investigate the influences of incident wind direction, upstream terrain conditions and interferences from the surroundings on the wind effects on the building. Serviceability of the super tall building under strong wind action was analyzed on the basis of the experimental results. On the other hand, full-scale measurements of wind effects on the Jin Mao Building were conducted under typhoon conditions. The field data, such as wind speed, wind direction and acceleration responses were simultaneously and continuously recorded during the passage of Typhoon Rananim in August, 2004. Analysis of the field data was carried out to investigate typhoon effects on the super tall building. Finally, the wind tunnel test results were found to be in good agreement with the full-scale measurements, illustrating that the wind tunnel tests can provide satisfactory predictions of wind-induced vibrations of the super tall building under typhoon conditions. [Copyright &y& Elsevier]

Di Wang Tower located in Shenzhen has a height of approximately 325 m and was the tallest building in Mainland China when it was built several years ago. The aspect ratio between the building’s height and transverse width is about 9, which has largely exceeded the criteria in the current design codes and standards in China. This super tall building may be susceptible to severe vibration induced by strong winds. This paper describes some results obtained from the full-scale measurements of wind effects on Di Wang Tower under typhoon condition. The field data, such as wind speed, wind direction and acceleration responses were simultaneously and continuously measured from this building during the passage of Typhoon Sally in 1996. Detailed analysis of the field data was conducted to investigate the typhoon effects on the super tall building. The characteristics of the typhoon-generated wind and the structural responses of the building are presented and discussed in detail. Dynamic characteristics of the building are reported, and comparisons with those from the analysis of the three-dimensional finite element model of Di Wang Tower are made. The serviceability of this super tall building under typhoon conditions is assessed based on the field measurements. The damping ratios of the building during the typhoon are evaluated, and the amplitude-dependent characteristics of damping that were obtained using the random decrement technique are presented on the basis of the field measurements. Furthermore, the full-scale measurements are compared with the wind tunnel test results to verify the reliability of wind tunnel experimental techniques. [Copyright &y& Elsevier]

A large amount of dust particles produced by the wind in an open-air pile is one of the important reasons for air pollution. Studying the law of dust diffusion in local areas is of great significance for the atmospheric particulate control. In this study, a pile of sodium carbonate in a large open-air pile in Weifang, China, is regarded as the research object. The dispersion characteristics of dust particles around the pile under the action of unidirectional wind are studied through wind tunnel test and numerical simulation. The complex atmospheric environment is simplified as unidirectional wind, and the influence of different wind speeds on the dispersion of particles with diverse sizes in the pile is studied. Although a large gap exists between the assumption and the real atmospheric environment, this study provides a reference for the evaluation of the pollution scope of blowing dust and prevention and control of pollution. Results show that a high-concentration range of the dust exists near the pile behind the wind direction and may continue to spread to the height due to the influence of a whirlpool, and the dispersion distance and width can increase with the increase in wind speed. The increase in particle diameter increases the kinetic energy loss of particles for the fluid. Under the same starting speed, the dispersion distance of dust decreases with the increase in particle diameter. With the increase in particle diameter, the dust concentration distribution presents the trend of interior hollowing and high-concentration area fragmenting., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Summary: A field monitoring program on an experimental low‐rise building with gable roof has been established and implemented at a typhoon‐prone area in China. This paper presents the field measurements obtained during two tropical cyclones in 2009. The characteristics of near‐ground winds during the tropical cyclones are reported and discussed, including wind velocity spectra and profiles of mean wind speed, turbulence intensity, and turbulence integral length scale. This paper focuses on analysis of the external surface pressures measured on the central cross section of the gable roof for winds normal to the ridgeline. Pressure coefficients, probability density functions, and power spectra of the measured wind pressures are analyzed in detail. In addition, wind tunnel experiment of pressure measurements on a 1:50‐scaled model of the experimental building is conducted. Comparison of the field measurements and the model test results is then performed. The paper aims to provide reliable full‐scale measurements for further understanding of wind pressures on the roof of a typical low‐rise building during tropical cyclones and as benchmarks for comparisons with wind tunnel experimental and numerical simulation results. [ABSTRACT FROM AUTHOR]