Wind characteristics at bridge site in a deep-cutting gorge by wind tunnel test

Abstract To study the wind characteristics at bridge site in a deep-cutting gorge, a gigantic bridge site terrain model was made in a wind tunnel. The effects of different oncoming wind directions on the wind characteristics over the bridge site were investigated in the simulated atmospheric boundary layer. Results show that the perpendicular wind speed profiles along the bridge main beam can be generally divided into two parts. The shapes of the wind speed profiles at the two bridge towers are much closer to the power law and log law than those of the bridge main beam. The wind attack angle required for the wind resistant design of the bridge should be determined in the range of −6° to 2°, which obviously exceeds the range of −3° to 3° that is usually considered in the homogeneous terrain. When the oncoming wind is from southwest, the wind power spectra at 1/4 span, mid-span and 3/4 span points match well with the spectra values by the Kaimal model. For two measurement points of the same distance, the decay factor of the coherence function varies along the bridge main beam as well as the bridge towers depending on their positions.

[1]  Leighton Cochran,et al.  A physical modeler's view of Computational Wind Engineering , 2011 .

[2]  P. J. Mason,et al.  Flow over an isolated hill of moderate slope , 1979 .

[3]  Satoru Iizuka,et al.  Performance of various sub-grid scale models in large-eddy simulations of turbulent flow over complex terrain , 2004 .

[4]  Y. Ge,et al.  Numerical study on turbulent boundary layers over two-dimensional hills — Effects of surface roughness and slope , 2012 .

[5]  Xinyu Xu,et al.  Numerical simulations of the mean wind speeds and turbulence intensities over simplified gorges using the SST k-ω turbulence model , 2016 .

[6]  Satoru Iizuka,et al.  Large-eddy simulations of turbulent flow over complex terrain using modified static eddy viscosity models , 2006 .

[7]  H. F. Xiang,et al.  Wind turbulence characteristics study at the Stonecutters Bridge site: Part II: Wind power spectra, integral length scales and coherences , 2009 .

[8]  Paul Carpenter,et al.  Investigation of wind speeds over multiple two-dimensional hills , 1999 .

[9]  José M. L. M. Palma,et al.  Numerical simulation of the atmospheric flow in a mountainous region of the North of Portugal , 1998 .

[10]  Leighton Cochran,et al.  Modeling of topographic wind speed effects in Hawaii , 2005 .

[11]  Guoqing Huang,et al.  The appropriate shape of the boundary transition section for a mountain-gorge terrain model in a wind tunnel test , 2015 .

[12]  Liao Haili.  Shape of boundary transition section for mountains-gorge bridge site terrain model , 2013 .

[13]  J. Kaimal,et al.  Spectral Characteristics of Surface-Layer Turbulence , 1972 .

[14]  T. Kármán.  Progress in the Statistical Theory of Turbulence , 1948 .

[15]  Alan G. Davenport,et al.  Guidelines for the calculation of wind speed-ups in complex terrain , 1998 .

[16]  H. F. Xiang,et al.  Wind turbulence characteristics study at the Stonecutters Bridge site: Part I-Mean wind and turbulence intensities , 2009 .

[17]  Jon A. Peterka,et al.  Development of a Powerful Hybrid Tool for Evaluating Wind Power in Complex Terrain: Atmospheric Numerical Models and Wind Tunnels , 2004 .

[18]  A. Davenport.  The spectrum of horizontal gustiness near the ground in high winds , 1961 .

[19]  C. Li,et al.  Wind tunnel modeling of flow over mountainous valley terrain , 2010 .

[20]  Hans A. Panofsky,et al.  Recent spectra of atmospheric turbulence , 1968 .

[21]  Chen Airong,et al.  Experimental Study of Wind Field in Bridge Site Located in Mountainous Area , 2006 .

[22]  F. Porté-Agel,et al.  On Monin–Obukhov Similarity In The Stable Atmospheric Boundary Layer , 2001 .

[23]  T. Uchida,et al.  Large-eddy simulation of turbulent airflow over complex terrain , 2001 .

[24]  J. Hunt,et al.  Turbulent wind flow over a low hill , 1975 .

[25]  T. Tamura,et al.  LES analysis of turbulent boundary layer over 3D steep hill covered with vegetation , 2007 .

[26]  P. Welch.  The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , 1967 .

[27]  J. Hunt,et al.  Turbulent shear flows over low hills , 1988 .

[28]  Robert N. Meroney,et al.  Wind-tunnel simulation of the flow over hills and complex terrain , 1980 .

[29]  A. J. Bowen,et al.  Modelling of strong wind flows over complex terrain at small geometric scales , 2003 .