Wind Tunnel Test of Wind-induced Snow Drift for Opening Arch Structure Based on Fractal Characteristics

Under the action of wind, snow particles will drift and deposit, which will adversely affect the surrounding area of the structures. For adjacent opening structures, the distribution of wind-induced snow around the structure is more complicated, and is not explicitly included in any design code. This problem is addressed herein by performing wind tunnel tests. Taking the single roof structure with opening and the double opening roof structures as the research object, the wind tunnel tests on the distribution of wind-induced snow were carried out; the influence of the orientation of openings on the distribution of snow on the surface and the surrounding area of the single arched structure was analysed; the influence of structures spacing and relative angle on snow distribution between two models was also analysed. Based on wind tunnel test data, through the comparison of the fractal characteristics of particles in the whole area, the wind-induced snow drift was analyzed quantitatively, which is of random fluctuation in external chaotic motion. The following results have been obtained. The structure opening has a significant effect on the distribution of snow around the roof structure. The snow at the corners of the windward edge of the roof structure is completely eroded, resulting in a horseshoe-shaped vortex. The snow on the leeward side of the structure creeps into the form of ripples. The snow distribution is favorable when the hole is located on the other vertical sides of the test specimen. The wind-induced snow between two structures is not a simple superposition of the individual models. As the spacing between the buildings is reduced, the snow deposition between the two structures is increased. When the opening angle of the two models is 30°, the structural stability is less favorable. Through the analysis of the fractal characteristics of the particle coverage area, the following results are obtained. The structure opening has a significant effect on the distribution of snow around the arch structure than relative angle. The roughness of snow on the central axis and the longitudinal axis is the smallest when hole is located on the other vertical sides of the structure. When the opening angle is 60°, the particle roughness is the largest, whereas the local maximum snow depth coefficient of 60° is lower than 30°. Therefore, the above arrangement should be avoided in the design. © 2022 Editorial Department of Journal of Sichuan University. All rights reserved.