With increasing urban density, aerodynamic interference among adjacent super high-rise buildings has emerged as a significant design concern. Although rounded-corner aerodynamics has been widely investigated, the combined influence of aerodynamic interference and aeroelasticity on design-relevant wind loads of roundedcorner super high-rise buildings remains insufficiently documented. This study investigates a rounded-squaresection super high-rise building with a 10% corner radius ratio via wind tunnel experiments using both rigid and aeroelastic models, systematically comparing wind loads under side-by-side, tandem, and staggered configurations. Results show that side-by-side and upstream interference configurations exert the strongest influence on pressure distributions. Under certain interference arrangements, aeroelastic effects cause non-negligible deviations in local pressure coefficients relative to rigid-model results. For cladding wind loads, modified peak factors indicate that side-by-side interference may noticeably increase local extreme suctions in representative cases, whereas aeroelastic effects exert a comparatively minor influence. For overall structural loads, representative interference arrangements can noticeably alter mean base-moment coefficients, indicating that aeroelastic effects should be considered when evaluating wind loads under aerodynamic interference. This study quantifies the combined effects of aerodynamic interference and aeroelasticity, offering a scientific basis for designing wind-resistant super high-rise buildings in dense urban environments.

The three-dimensional Large Eddy Simulation (LES) method is conducted to investigate the flow characteristics around the square cylinder under a Reynolds number of Re = 2000. The considered corner chamfered ratio C/D ranges from 0% to 50% with an interval of 5%, where C is the chamfered corner dimension and D is the cylinder width. The focus is given on how C/D influences the flow structure, wake recirculation region, flow separation bubbles, Strouhal number and aerodynamic forces of the cylinder. The numerical results indicate that with increasing C/D, the mean drag coefficient, fluctuating lift coefficient, mean pressure coefficient and fluctuating pressure coefficient decrease. Concurrently, the Strouhal number exhibits an initial increase followed by a decrease with a rise in C/D. Significant changes in the recirculation length and wake width are observed within 0% <= C/D <= 50%. The introduction of corner chamfers induces wall-attached evolution of the separated shear layers and suppresses three-dimensional instabilities, significantly attenuating the pressure fluctuating on the surfaces, thereby reducing both mean drag and fluctuating lift coefficients. As the chamfered ratio increases, the wake topology undergoes a transition from disordered fragmented structures to spanwise highly coherent periodic vortices, leading to a narrowband spectral transformation of the power spectra density. Finally, the mathematical relationships between the corner chamfered ratio and the aerodynamic force coefficients and Strouhal number are established.

To examine the impact of mutual interference between buildings on the wind loads acting on disturbed structures, a study was conducted using two identical square-section ultrahigh-rise buildings with a height-to-width ratio of 6:1. The wind tunnel pressure test considering aeroelastic effect was carried out. The results indicate that the influence of the aeroelastic effect is significant when the interfering building is positioned obliquely upstream or in a juxtaposed configuration. Then, the presence of upstream buildings reduces the mean pressure coefficient (CP, mean) of the disturbed building. However, when the interfering building is positioned directly upstream, the interference effect leads to an increase in the root mean square of the pressure coefficient (CP, rms) at most corner points of the disturbed building. Regardless of how the wind angle changes, except for some locations upstream of the interfering building, the extreme value of the wind pressure coefficient of the disturbed building often appears near the corner of the windward side of the building. The interference from different positions has varying effects on the mean aerodynamic force coefficients. Specifically, interference from an upstream oblique position increases the mean lift coefficient (CL, mean) of the disturbed building, whereas interference from a downstream oblique position increases the mean drag coefficient (CD, mean). The power spectrum of the aerodynamic force coefficients is most notably influenced by a building positioned directly upstream. Furthermore, as the wind direction angle increases, the changes in the power spectrum become more pronounced.

The unsteady Reynolds-averaged Navier–Stokes method is carried out to investigate the flow over two tandem 5:1 rectangular cylinders for a fixed spacing ratio of L/D = 6 with a Reynolds number of 4.4 × 104, where L is the distance between the leeward side of the upstream cylinder and the windward side of the downstream cylinder and D is the cylinder depth. The aerodynamic behaviors, including aerodynamic force coefficients, pressure distribution, vortex shedding frequency, and flow structure, are studied with angles of attack α = 0° to −15°. The numerical results indicate that the separated flow is highly sensitive to α and the flow structures are classified into three patterns: separated-reattached (α = 0°), fully separated (α = −2° to −8°), and separated-shrunk (α = −10° to −15°) flow. As α declines, the absolute value of the aerodynamic force coefficients of the upstream cylinder overall monotonically increases but that of the downstream cylinder changes non-monotonically. The Strouhal number decreases first and then keeps constant with the decrease in α. Both aerodynamic forces and vortex shedding frequency exist as a mutation at the transition of flow structure. As α wanes, the separation bubble around the top surface of the upstream cylinder gradually decreases, while that around the bottom surface grows first and then weakens, which does not reattach as α ≤ −2° and shrinks at α ≤ −10°. Meanwhile, the complex variations of separation bubbles around the downstream cylinder are analyzed. This study provides a reference for the wind-resistant design of parallel twin-deck bridges under high angle of attack.

The coal shed serves as a critical infrastructure in industrial operations, ensuring the protection and efficient handling of coal, thereby enhancing operational efficiency and environmental compliance. To examine the impacts of adjacent structures, interference distances, and wind angles on the wind loads acting on large-span coal sheds, a comprehensive experimental study was conducted using a coal shed with dimensions of 460 m x 157 m x 50 m. In this study, two distinct dimensions of interference buildings and five distinct interference distances were established. Wind tunnel pressure measurement tests were then carried out at 19 distinct wind angles to evaluate the influence of these variables on the wind load acting on the coal shed. The findings reveal that when the interfering structures are positioned downstream, the interference leads to an augmentation ranging from 0.15 to 0.30 in the mean shape coefficient of the disturbed coal shed. Notably, variations in building structure dimensions and interference distances exert insignificant influence on this coefficient. Conversely, when the interfering building structures are situated upstream, they exhibit a shielding effect. Specifically, under the influence of a larger structure, the mean and fluctuating shape coefficient of the coal shed undergo the most substantial alteration at 0.125D, whereas for a smaller structure, the most significant effect is observed at 0.75D. The perturbation of the adjacent building structure induces positive wind pressure on the windward surface of the disturbed coal shed, and the wind suction at the wake of the disturbed coal shed increases by 1.6 times. The overall force acting on the disturbed coal shed decreases in the presence of interference effects. However, the impact of the larger structure leads to an increase in the overall force experienced by the disturbed coal shed within a wind angle range of 80 degrees to 120 degrees, attaining a maximum increment of 26%. At equivalent distances, the influence exerted by the larger building is more pronounced. Consequently, the results of this study provide a valuable reference for the wind resistance design considerations of such structures.

Grid-generated turbulence is one of the most commonly used methods for simulating turbulent wind environments in wind engineering, and the conventional large eddy simulation approach that entity grids should be built and meshed in the computational domain for grid-generated turbulence suffers from prohibitive computational costs. To this end, a virtual grid-generated turbulence method that employs mathematical functions to precisely control inlet velocity distributions is proposed in this study. The influence of boundary conditions, incoming wind speed, kinematic viscosity, and grid size (width and spacing) on turbulence characteristics is systematically investigated. Furthermore, the aerodynamic forces and flow field mechanism of a 4:1 rectangular cylinder with different turbulence intensities are also comprehensively studied. The results indicate that the turbulence field generated by the proposed virtual grid-generated method exhibits excellent uniformity and isotropy. The effect of boundary conditions, incoming wind speed, and kinematic viscosity on turbulence field characteristics can be negligible. With the increase in turbulence intensity, vortex shedding from the rectangular cylinder is significantly suppressed, leading to reductions in the mean drag coefficient and the base suction coefficient but amplification in the fluctuating lift coefficient. This study not only provides a convenient and efficient LES turbulence generation method for structural wind-resistant analysis under turbulent conditions but also offers important theoretical support to estimate the aerodynamic performance of bluff bodies in complex wind fields.

To make an accurate prediction of the non-Gaussian characteristics of wind pressure for the airport terminal, this study combines the Proper orthogonal decomposition (POD) technique, convolutional neural network (CNN), and long short-term memory (LSTM) network to propose a novel POD-CNN-LSTM framework. Then, the proposed framework was well validated based on the wind tunnel testing of an airport terminal structure, and some error criteria, such as mean square root error and correlation coefficient, were adopted to evaluate the prediction accuracy of the non-Gaussian characteristics. Furthermore, two other methods, POD-CNN and POD-LSTM, were also used to conduct a comparative study. The obtained results illustrate that compared to POD-CNN and POD-LSTM, the proposed framework can achieve better performance on the fluctuating wind pressure coefficient. For predictions of non-Gaussian characteristics, the output results of the proposed POD-CNN-LSTM show fewer errors, which means the predictions are close to the measured results, including skewness, kurtosis, and wind pressure probability density distributions. To summarize, the proposed POD-CNN-LSTM framework shows superiority over others, which means the proposed framework has good potential for the practical application of non-Gaussian prediction of the engineering structure.

To make an accurate prediction of the non-Gaussian characteristics of wind pressure for the long-span roof, this study combines the proper orthogonal decomposition (POD) technique, convolutional neural network (CNN), and long short-term memory (LSTM) network to propose a novel POD-CNN-LSTM framework. Then, the proposed framework was well validated based on the wind tunnel testing of a long-span roof structure, and some error criteria, such as mean square root error and correlation coefficient, were adopted to evaluate the prediction accuracy of the non-Gaussian characteristics. Furthermore, two other methods, POD-CNN and POD-LSTM, were also used to conduct a comparative study. The obtained results illustrate that compared to POD-CNN and POD-LSTM, the proposed framework can achieve better performance on the pulsating wind pressure coefficient. For predictions of non-Gaussian characteristics, the output results of the proposed POD-CNN-LSTM show fewer errors, which means the predictions are close to the measured results, including skewness, kurtosis, and wind pressure probability density distributions. To summarize, the proposed POD-CNN-LSTM framework shows superiority over others, which means the proposed framework has good potential for the practical application of non-Gaussian prediction of the engineering structure.

This study investigated the statistical properties of the pressure fluctuations on a square cylinder across three distinct turbulence fields characterized by varying turbulent integral scales. The effect of turbulent integral scale on the non-Gaussian characteristics and extreme surface wind pressure acting on square cylinders beneath the separating flow were studied in detail. The findings indicated that the pressure distribution on the windward surface generally conformed to a Gaussian distribution, whereas notable non-Gaussian characteristics were observed in the pressure distribution on the side and leeward surfaces. The fluctuating pressure, skewness, kurtosis, peak factor, and extreme pressure increase with an increasing ratio of turbulent integral scale to structural depth (Lux/D), whereas the mean pressure remains unaffected by variations in Lux/D. As Lux increased, the energy of the internal vortices in the shear layer also increased. As a result, the non-Gaussian features of the pressure caused by vortex breakdown become more pronounced. Compared with Lux/D = 1.96, the underestimated value of the extreme pressure on the square cylinder had a maximum difference of up to 15.4% at Lux/D = 0.53. Therefore, the corresponding turbulent integral scale should be accurately simulated when measuring wind loading on a structure through wind tunnel tests.

This paper investigates the VIV responses and triggering mechanisms of a closed-box girder by wind tunnel experiments and computational fluid dynamics (CFD) simulations. The effects of handrails, gantry rails, and guide vanes (GVs) on the mitigation of VIV are analyzed. The results show that large-scale vortices shed from handrails and gantry rails result in large heaving VIV responses. The torsional VIV occurs due to the alternate vortex shedding in the wake. A handrail with a higher porosity near the upper deck surface is highly effective in suppressing VIV responses, especially for heaving VIV. Gantry rails installed at the medial position of the lower deck surface can mitigate torsional VIV to a large extent. GVs installed inside the gantry rails can mitigate torsional VIV much more significantly than one installed outside. For the girder with high-porosity handrails and GVs installed inside the gantry rails, the large-scale vortices generated by the handrails disappear, and the scale of the vortices induced by the GVs is notably reduced, thereby eliminating the heaving VIVs. Additionally, the vortex scale is reduced in the wake region, while the distance between the girder and vortex shedding increases. This effect significantly reduces torsional VIVs.

The turbulence integral scale significantly impacts the fluctuating pressures on buildings, but current wind tunnel tests do not adequately simulate this scale, potentially leading to structural hazards. In four turbulence flows, measurements are taken on a CAARC-scaled model (a standard tall building proposed by the Commonwealth Advisory Aeronautical Research Council). These flows, approximately of the same intensity (12%) but with different integral scales, are generated using a uniform grid to explore the turbulence integral scale's influence on the side surfaces' fluctuating pressures. The results indicated that the fluctuating pressure coefficients increase with the ratio of turbulence integral scale to model thickness Lux/D, while the mean pressure coefficients are minimally affected by the turbulence integral scale. A larger turbulence integral scale imparts more energy but does not change the energy distribution. The power spectrum and the aerodynamic admittance of fluctuating pressure exhibit a peak around the vortex-shedding frequency. An empirical model of aerodynamic admittance that considers this peak and the ratio of turbulence integral scale to model thickness Lux/D is proposed to correct the simulated errors in wind tunnel tests. Although the simulated root mean square (RMS) of fluctuating pressure coefficients deviates by up to 26% and 37% when the simulated integral scale is approximately 0.26 and 0.40 times the target scale, respectively, the error margin of the modified RMS remains within 5%.

Aiming the issue of wind pressure distribution characteristics of airport terminal glass curtain walls in mountainous areas, wind tunnel tests have been conducted to investigate glass curtain walls in airport terminals under different terrains (at mountain heights of 0, 30, 60, 90 m [H1, H2, H3, H4] and under surrounding high mountains of 80, 130, 150 m [H5, H6, H7]). Based on experimental data, a comparative analysis was conducted on the effects of different terrains on the mean and pulsating wind pressures, non-Gaussian characteristics, peak factor, and extreme wind pressure. The results show that the larger values of the mean and pulsating wind pressures under different terrains appear at the corners of the curtain wall edges. Furthermore, the skewness, kurtosis, and wind pressure probability density function values at the corners of the curtain wall edges significantly deviate from the standard Gaussian distribution, exhibiting significant non-Gaussian characteristics. The majority values of peak factors range from 3.5 to 5.0, far higher than the recommended value of 2.5 in Chinese specification and code (GB 50009-2012). Moreover, the values of extreme wind pressure under terrains H1, H2, H3, and H4 were greater than that under terrains H5, H6, and H7. At mountain heights H1, H2, H3, and H4, the increasing mountaintop height has a certain increasing effect on the extreme wind pressure. The maximum increase of 96.5% and 82.8% in mountain height H3 and H4 compared to H1. However, the increase in the height of surrounding mountains has a reducing effect on the extreme wind pressure. Research can provide useful suggestions and references for the design, construction, and site selection of terminals in similar airports.

Supertall buildings and long-span bridges are significantly affected by wind-induced vibrations, and the wind fields in mountainous areas are highly complex and influenced by the oncoming wind speed and turbulence intensity. To accurately determine the variation patterns of wind characteristics in mountainous areas under different oncoming wind speeds and turbulence intensities, large eddy simulation (LES) was employed to analyze wind fields over simplified hill and ridge models. By setting different basic wind speeds (5, 10, 15, and 20 m/s) and turbulence intensities (1%, 3%, 5%, and 10%) at the inlet, the variation patterns of wind characteristics over the simplified hill and ridge under atmospheric boundary layer inflow were studied, revealing wind field flow mechanisms. The results indicate that the wind characteristics on the leeward side of the simplified hill and ridge are significantly influenced by the oncoming wind speed and turbulence intensity. Increasing the oncoming wind speed and turbulence intensity leads to decreased wind profile deceleration, reduced changes in wind direction and attack angles, and increased wind speed amplification factor. In addition, the turbulence fluctuations, power spectra, and coherence function between two points on the leeward side increase with the oncoming wind speed and turbulence intensity. The turbulent integral scale decreases with an increase in the oncoming wind speed and turbulence intensity. As the wind speed and turbulence increase, the size of the recirculation bubble gradually decreases, with its center moving closer to the wall surface. In the vorticity field, the number of smaller-scale three-dimensional turbulent vortices near the hill and ridge increases. These differences in flow characteristics are the fundamental causes of the changes in wind characteristics. High wind speeds and turbulence intensities typically result in higher kurtosis and skewness, with significant non-Gaussian characteristics in the fluctuating wind. Traditional wind load design specifications for building architecture based on a Gaussian distribution may not be applicable to mountainous terrain. In practical engineering, the influences of the oncoming wind speed and turbulence intensity on wind characteristics should be fully considered.

To investigate the wind pressure distribution characteristics of a long-span roof in a mountainous area with different terrains (at mountain heights of H1, H2, H3, and H4, and under the surrounding high mountains of H5, H6, and H7), a series of synchronised pressure tests were conducted on a rigid model of an airport terminal roof. The effects of different terrains on the mean wind pressure, fluctuating wind pressure, skewness, kurtosis, probability density function, peak factor, and extreme wind pressure on the roof were compared and analysed. The results reveal a significant increase in the mean and fluctuating wind pressure coefficients at the windward leading edge of the roof at higher mountain heights. Furthermore, increasing mountain height causes the skewness, kurtosis, and probability density functions to deviate from the standard Gaussian distribution, exhibiting strong non-Gaussian characteristics. Most pressure taps on different terrains exhibit peak factors between 4 and 4.5, surpassing the recommended Chinese code peak factor of 2.5. Moreover, the absolute values of the minimum extreme negative pressure on terrains H1, H2, H3, and H4 at all wind angles are greater than those on terrains H5, H6, and H7. The maximum increase was 44.9 % for terrain H4 compared with terrain H1. Hence, topographic effects should be carefully considered when estimating extreme wind loads on long-span roofs using wind tunnel tests.

On the basis of the definition and the three-dimensional characteristics of an integrated transfer function, the transfer function identification method based on reasonable technical means considering the three-dimensional effect was proposed. An original method to predict the bridge buffeting responses directly using the integrated transfer function is presented and investigated by means of segmental model vibration tests. Taking a suspension bridge as the background, the integrated transfer function was identified using segmental model vibration tests, and the effect of span-width ratio on it was studied. The buffeting response test of a full-bridge model was carried out in two different wind fields. Further, the identified integrated transfer functions were applied to predict the buffeting responses of the full-bridge model. By comparing the results, it is demonstrated that the method using reasonable segmental model vibration tests to obtain the integrated transfer functions to predict the bridge buffeting responses was highly accurate. The feasibility of the proposed method according to segmental model vibration tests was verified through tests for the first time. The method can effectively improve the deviation of results arise from the inaccurate simulating of turbulent characteristics in the tests, and avoid the many limitations of pressure and force measurement methods.

The prediction of bridge buffeting response is inseparable from wind tunnel test technology. Unfortunately, there is an inevitable deviation between the fluctuating wind characteristics simulated and that of the atmospheric boundary layer, resulting in obvious errors in the predicted bridge buffeting responses. In addition, there is no case report of successfully predicting the bridge buffeting response based on segmental model vibration tests. To increase the precision of response prediction of actual bridge, a definition of integrated transfer function and its identification method based on reasonable measuring means was proposed. Furthermore, an original method to predict the bridge buffeting responses was presented. Taking a suspension bridge as the background, the integrated transfer functions were identified and the effect of structural span-width ratio was studied. It is demonstrated that the method using reasonable segmental model vibration tests to identify the integrated transfer functions to predict the bridge buffeting responses was highly accurate.

In this paper, the fluctuating lift and drag forces on 5:1 rectangular cylinders with two different geometric scales in three turbulent flow-fields are investigated. The study is particularly focused on understanding the influence of the ratio of turbulence integral length scale to structure characteristic dimension (the length scale ratio). The results show that both fluctuating lift and drag forces are influenced by the length scale ratio. For the model with the larger length scale ratio, the corresponding fluctuating force coefficient is larger, while the spanwise correlation is weaker. However, the degree of influence of the length scale ratio on the two fluctuating forces are different. Compared to the fluctuating drag, the fluctuating lift is more sensitive to the variation of the length scale ratio. It is also found through spectral analysis that for the fluctuating lift, the change of length scale ratio mainly leads to the variation in the low frequency part of the loading, while the fluctuating drag generally follows the quasi-steady theory in the low frequency, and the slope of the drag spectrum at high frequencies changes with the length scale ratio. Then based on the experimental data, two empirical formulas considering the influence of length scale ratio are proposed for determining the lift and drag aerodynamic admittances of a 5:1 rectangular cylinder. Furthermore, a simple relationship is established to correlate the turbulence parameter with the fluctuating force coefficient, which could be used to predict the fluctuating force on a 5:1 rectangular cylinder under different parameter conditions.

o investigate the non-Gaussian properties of fluctuating wind pressures and the error margin of extreme wind loads on a long-span curved roof with matching and mismatching ratiosof turbulence integral scales to depth (????????????/????), a series of synchronizedpressure tests on the rigid model of the complex curved roof were conducted. The regions of Gaussian distribution and non-Gaussian distribution were identified by two criteria, which were based on the cumulative probabilities of higher-order statistical moments (skewness and kurtosis coefficients, Skand Ku) and spatial correlation of fluctuating wind pressures, respectively. Then the characteristics of fluctuating wind-loads in the non-Gaussian region were analyzed in detail in order to understand the effects of turbulence integral-scale. Results showed that the fluctuating pressures with obvious negative-skewness appear in the area near the leading edge, which is categorized as the non-Gaussian region by both two identification criteria.Comparing with those in the wind field with matching????????????/????, the range of non-Gaussian region almost unchanged with a smaller ????????????/????, while the non-Gaussian features become more evident, leading to higher values of Sk, Kuand peak factor. On contrary, the values of fluctuating pressures become lower in the wind field with a smaller????????????/????, eventually resulting in underestimation of extreme wind loads. Hence, the matching relationship of turbulence integral scaleto depthshould be carefully considered as estimating the extreme wind loads of long-span roof by wind tunnel tests

为了研究板桁结合加劲梁悬索桥的颤振稳定性,以国内某大跨悬索桥为背景,通过节段模型风洞试验分别研究了上、下中央稳定板以及水平稳定板的制振效果,并考察了阻尼比对主梁颤振临界风速的影响,最后对比研究了原设计方案和安装上中央稳定板的板桁结合加劲梁的三分力系数.研究结果表明:上中央稳定板可以有效抑制板桁结合加劲梁颤振,且颤振临界风速增长率随稳定板高度的增加呈非线性变化;安装于桥面下方的下中央稳定板不能改善主梁的颤振性能,但安装于下平联处的下中央稳定板可以在一定程度上提高主梁的颤振临界风速;安装于桥面板边缘处的水平稳定板会恶化主梁的颤振稳定性;将上、下中央稳定板联合使用时主梁可以取得更好的颤振性能.阻尼比对以扭转颤振为主的板桁结合加劲梁具有显著影响;安装与栏杆等高的上中央稳定板在小攻角范围内对主梁三分力系数的影响很小.

To study the effects of the turbulence integral scale on the non-Gaussian properties and extreme wind loads of surface pressure, the surface pressures for two Commonwealth Advisory Aeronautical Research Council (CAARC) scaled models were measured in three turbulent flow fields with different turbulence integral scales. The results show that the surface pressure distribution on the windward surface is fundamentally Gaussian, while the surface pressures on the side and leeward surfaces are markedly non-Gaussian. The deviation from normality strongly depends on the ratio of the turbulence integral scale to the windward width (Lux/D). With changing Lux/D, the fluctuating pressure, skewness, kurtosis, probability density distribution, non-Gaussian peak factors, and extreme wind loads vary significantly. In addition, the surface pressure nonnormality becomes more evident for lower Lux/D wind fields, increasing Sk, Ku, and the fluctuating pressure's peak factor. In contrast, the fluctuating pressure decreases with decreasing wind-field Lux/D, resulting in the underestimation of extreme wind loads. Further, the extreme wind load maximal error margin reaches 30.7% when the simulated turbulence integral scale error margin is 70%, even for nonnormal surface pressures. Hence, nonnormality of the surface pressure and the effects of the turbulence integral scale should be carefully considered when estimating extreme wind loads for CAARC standard tall buildings using wind-tunnel tests. (c) 2022 American Society of Civil Engineers.