Topic: New progress in research on roof snow load for long-span structures

Prof. Feng Fan, Professor, the recipient of National Science Foundation for Distinguished Young Scholar, the vice-president of Harbin Institute of Technology, the director of Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, and the chief structural engineer of Chinese national science project “Five-hundred-meter Aperture Spherical radio Telescope (FAST)”, who has been engaged in the research in the realms as diverse as the wind and snow loads of the long-span spatial structure, the static and dynamic stability of the long-span spatial structure, the seismic performance and the failure mechanism of the long-span spatial structure under the strong earthquake, the innovative study and application of the long-span spatial structure, the mechanism of resistant blasting and impacting, and key technologies of structural analyses of the FAST. And has won awards including but not limited to the Second Award of the Second Prize of State Scientific and Technological Progress, the China Youth Science and Technology Award, and the Zhan Tianyou Civil Engineering Award.

Abstract: Roofs in cold regions with heavy snowfalls could experience unbalanced or non-uniform snow loads caused by snow drifting or sliding, which could cause significant damage or collapse to the roof. The unbalanced snow load patterns recommended by the Chinese design code have been calibrated several times, but documents to support such codifications are unclear. Besides, the provisions are mainly specified for regular-sized roofs but not long-span space roofs. With the growing of applications of long-span space roofs in recent years in China, there are practical demands for investigations of unbalanced snow loads on them since such investigations are rarely available. Therefore, an investigation of the unbalanced snow loads on roofs, especially for long-span space roofs, is warranted. This lecture summarizes some of the research activities on this subject at Harbin Institute of Technology (HIT). Firstly, relying on the advantages of low temperature and snowy climate in Harbin, the snow distribution of various full-size and scaled roofs has been measured and studied for 12 years. A large number of detailed data about the distribution characteristics of roof snow and meteorological conditions have been obtained and been successfully applied to the revision of Chinese load code. Secondly, based on the traditional multiphase flow theory, an innovative mixture numerical approach was developed and applied to the study on wind-induced snow drift on building roofs. The snow particulate property, snow drift process, and the melting & recrystallization process of roof snow caused by building heating and sunshine were studied by using the proposed approach. Finally, a set of wind-snow joint test system was independently developed, a similarity criterion of wind-snow joint test was proposed, and a large number of studies were carried out on snow distributions for different kinds of roofs. Furthermore, a new special facility, i.e., Simulator of Natural Action of Wind-Rain-Heat-Snow for Space Structures, has been built to more comprehensively consider the drifting, melting and recrystallization processes of roof snow.