Design Wind Speed Estimation for Long Span Bridges in Korean Southern and Western Coasts

Recently, many long-span cable supported bridges, including the cable stayed bridges and the suspension bridges, have already been constructed or are planned for construction. Because the meteorological values used to estimate the wind load for designing the long-span bridges were based on data from the 1960s through 1995 in Korea, it is necessary to reconsider the proper design wind load for long-span bridges. In this paper, the research area is confined to the southern and western coasts of Korea where many long-span bridges have been built. The method of moment and the least-squares method are used to estimate the expected wind speeds of a 100-year return period for girder bridges; Gumbel’s distribution is used to estimate the expected wind speeds of a 200-year return period for long-span bridges. As the return period wind speed on the land surface is revised because of recent high-speed velocity, the revised return period wind speed is increased by 17%. The compatibility of return period wind speed is also evaluated using the RMS (root mean square) error method. This paper concludes that the least-squares method is more compatible than the method of moment for the case of the southern and western coasts of Korea.

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Wind Tunnel Studyon Vortex-Induced Vibration Characteristics of Long-Span Suspension Bridges with Single Cable Plane

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.633-634.1263 ◽

2014 ◽

Vol 633-634 ◽

pp. 1263-1266

Author(s):

Huang Yu

Keyword(s):

Wind Tunnel ◽

Suspension Bridge ◽

Wind Tunnel Experiment ◽

Vibration Characteristics ◽

Torsional Stiffness ◽

Suspension Bridges ◽

Vortex Induced Vibration ◽

Long Span Bridges ◽

Wind Speeds ◽

Long Span

For modern long-span bridges, both the optimization of aerodynamic shape and the increase of torsional stiffness according to the result of the wind tunnel experiment could avoid the flutter instability.Vortex-inducedvibration with relatively large amplitude happens easily at low wind speeds. In this paper, based on wind tunnel experiment, by studying on the vortex-induced vibration characteristics of a long-span suspension bridge with single cable plane, aerodynamic measures for easing the vortex-induced vibration are given.

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A predictive critical flutter wind speed modeling for long-span bridges

Advances in Structural Engineering ◽

10.1177/1369433219900977 ◽

2020 ◽

Vol 23 (9) ◽

pp. 1823-1837

Author(s):

Kun Lin ◽

Minghai Wei ◽

Hongjun Liu ◽

Huafeng Wang

Keyword(s):

Wind Speed ◽

Wind Tunnel ◽

Dimensional Space ◽

Three Dimensional ◽

Wind Tunnel Tests ◽

Long Span Bridges ◽

Wind Speeds ◽

Long Span ◽

Aerodynamic Model ◽

Proposed Model

In this article, a two-dimensional Lighthill aerodynamic model is first extended to three-dimensional space, and then combined with the larger Von Karman plate deformation theory, a model for predicting the critical flutter wind speeds of long-span bridges in the primary design is proposed. The predictions of the presented model are compared to the results of wind tunnel tests for five long-span bridges with different main girder section forms. After that, based on the proposed model, the effects of width to span ratio and thickness to span ratio on the critical flutter wind speeds of long-span bridges are investigated. The results show that the differences between the proposed model and wind tunnel tests are only 7%–14%. Therefore, the presented model can assess the flutter wind speed in preliminary design stages of a bridge. The results also reveal that width to span ratios between 1/30 and 1/10 and thickness to span ratios between 1/300 and 1/100 are optimal for long-span bridges.

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Basis for recommending an update of wind velocity pressures in Canadian design codes

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2013-0287 ◽

2014 ◽

Vol 41 (3) ◽

pp. 206-221 ◽

Cited By ~ 10

Author(s):

H.P. Hong ◽

T.G. Mara ◽

R. Morris ◽

S.H. Li ◽

W. Ye

Keyword(s):

Wind Speed ◽

Wind Velocity ◽

Return Period ◽

Least Squares Method ◽

Gumbel Distribution ◽

Generalized Least Squares ◽

Generalized Extreme Value Distribution ◽

Design Codes ◽

Distribution Fitting ◽

Wind Speeds

Reference wind velocity pressures corresponding to specified return period wind speeds are provided in several Canadian design codes. A review of the two most recent editions of the National Building Code of Canada (NBCC) indicates that significant changes in some 50-year return period wind speeds, vAH-50, were introduced in the 2010 version of the NBCC-2010 compared to the previous NBCC-2005. The changes are due to analysis approaches, available wind records, and a re-examination of anemometer histories. To potentially improve the estimates of vAH-50, wind records in the Environment Canada HLY01 digital archive were processed. Two hundred and thirty-five meteorological stations are considered in the analysis, and height and exposure corrected annual maximum hourly-mean wind speed, VAH, are extracted. Statistical analysis and distribution fitting were carried out using the Gumbel distribution and generalized extreme value distribution and several fitting methods were employed. The results indicate that it is preferable to treat VAH as a Gumbel variate, and to carry out the fit using the generalized least-squares method. Wind speed contour maps for Canada are developed based on the estimated vAH-T for T equal to 50, 500, and 1000 years. A comparison of the maps of vAH-50 to those inferred from NBCC-2005 and NBCC-2010 shows that the developed map retains some of the smoothness of the wind speeds exhibited in NBCC-2010, while maintains the localized wind speed features presented in NBCC-2005. Results also show that the wind speed corresponding to the factored design wind load in NBCC-2010 is associated with a return period ranging from 200 to 5000 years, but for 90% of stations considered, the range narrows to 300 to 900 years.

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Suppression of Bridge Flutter Using Suction Control

Advances in Civil Engineering ◽

10.1155/2021/1788691 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Shibo Tao

Keyword(s):

Wind Speed ◽

Leeward Side ◽

Suction Velocity ◽

Long Span Bridges ◽

Wind Speeds ◽

Long Span ◽

Suction Control ◽

Long Span Bridge ◽

Section Model ◽

Derivatives Of

To verify the effectiveness of the suction-based method for improving flutter stability of long-span bridges, the forced vibration experiments for extracting the flutter derivatives of a section model with and without suction were performed, and the corresponding critical flutter wind speeds of this structure were calculated out. It is shown by the experiment that the flutter stability of the bridge depends on suction configuration. As the suction holes locate at the leeward side of the model, the critical flutter wind speed can attain maximum under the same suction velocity. In the analytical results, it is remarkably effective that the suction control improves the long-span bridge flutter stability.

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Analysis of Wind Field Fan Based on Performance Enhancement Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.986-987.235 ◽

2014 ◽

Vol 986-987 ◽

pp. 235-238

Author(s):

Xiao Long Tan ◽

Jia Zhou ◽

Wen Bin Wang

Keyword(s):

Wind Speed ◽

Wind Turbines ◽

Performance Enhancement ◽

Aerodynamic Performance ◽

Wind Load ◽

Wind Speeds ◽

Enhancement Method ◽

Changes Over Time ◽

Load Simulation ◽

Single Constant

For the simulation of wind turbine, the wind speed is extremely important parameters and indicators to measure the output power of the unit is the wind load. Therefore, in the airflow dynamics and simulation of wind loads before establishing an accurate wind speed model is crucial. At present, the application for wind turbines COMSOL fan, fan blades and wind load simulation field, the extremely important wind speed model is not perfect, most of the research is confined to a single constant wind speed, wind speed virtually ignored the magnitude and direction of change, on changes over time and space at the same time is one of the few studies of wind, so find a way to accurately describe the range of wind speeds, and can be combined well with COMSOL method can greatly improve the aerodynamic performance of wind turbines the overall level of .

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Influence of Wind Speed, Wind Direction and Turbulence Model for Bridge Hanger: A Case Study

Symmetry ◽

10.3390/sym13091633 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1633

Author(s):

Yang Ding ◽

Shuang-Xi Zhou ◽

Yong-Qi Wei ◽

Tong-Lin Yang ◽

Jing-Liang Dong

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Wind Field ◽

Solid Mechanics ◽

Von Mises Stress ◽

Long Span Bridges ◽

High Rise ◽

Long Span ◽

Cfd Models ◽

Von Mises

Wind field (e.g., wind speed and wind direction) has the characteristics of randomness, nonlinearity, and uncertainty, which can be critical and even destructive on a long-span bridge’s hangers, such as vortex shedding, galloping, and flutter. Nowadays, the finite element method is widely used for model calculation, such as in long-span bridges and high-rise buildings. In this study, the investigated bridge hanger model was established by COMSOL Multiphysics software, which can calculate fluid dynamics (CFD), solid mechanics, and fluid–solid coupling. Regarding the wind field of bridge hangers, the influence of CFD models, wind speed, and wind direction are investigated. Specifically, the bridge hanger structure has symmetrical characteristics, which can greatly reduce the calculation efficiency. Furthermore, the von Mises stress of bridge hangers is calculated based on fluid–solid coupling.

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Frequency Distribution Model of Wind Speed Based on the Exponential Polynomial for Wind Farms

Sustainability ◽

10.3390/su11030665 ◽

2019 ◽

Vol 11 (3) ◽

pp. 665 ◽

Cited By ~ 1

Author(s):

Lingzhi Wang ◽

Jun Liu ◽

Fucai Qian

Keyword(s):

Wind Speed ◽

Frequency Distribution ◽

Least Squares Method ◽

Wind Farms ◽

Rayleigh Distribution ◽

Distribution Model ◽

Exponential Polynomial ◽

Distribution Models ◽

Wind Speed Data ◽

Wind Speeds

This study introduces and analyses existing models of wind speed frequency distribution in wind farms, such as the Weibull distribution model, the Rayleigh distribution model, and the lognormal distribution model. Inspired by the shortcomings of these models, we propose a distribution model based on an exponential polynomial, which can describe the actual wind speed frequency distribution. The fitting error of other common distribution models is too large at zero or low wind speeds. The proposed model can solve this problem. The exponential polynomial distribution model can fit multimodal distribution wind speed data as well as unimodal distribution wind speed data. We used the linear-least-squares method to acquire the parameters for the distribution model. Finally, we carried out contrast simulation experiments to validate the effectiveness and advantages of the proposed distribution model.

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