【正文】 學(xué) 號(hào)： ********** 指 導(dǎo) 教 師： 2020 年 12 月 25 日 Acrosswind loads and effects of supertall buildings and Structures Abstract Acrosswind loads and effects have bee increasingly important factors in the structural design of supertall buildings and structures with increasing height. Acrosswind loads and effects of tall buildings and structures are believed to be excited by inflow turbulence, wake, and inflowstructure interaction, which are very plicated. Although researchers have been focusing on the problem for over 30 years, the database of acrosswind loads and effects and the putation methods of equivalent static wind loads have not yet been developed, most countries having no related rules in the load codes. Research results on the acrosswind effects of tall buildings and structures mainly involve the determination of acrosswind aerodynamic forces and acrosswind aerodynamic damping, development of their databases, theoretical methods of equivalent static wind loads, and so on. In this paper we first review the current research on acrosswind loads and effects of supertall buildings and structures both at home and abroad. Then we present the results of our study. Finally, we illustrate a case study in which our research results are applied to a typical supertall structure. Introduction With the development of science and technology, structures are being larger, longer, taller, and more sensitive to strong wind. Thus, wind engineering researchers are facing with more new challenges, even problems they are currently unaware of. For example, the construction of super tall buildings is now prevalent around the world. The Chicago Sears Tower with a height of 443 m has kept the record of the world’s tallest building for 26 years now. Dozens of supertall buildings with heights of over 400 m are set to be constructed. Burj Dubai Tower with a height of 828 m has just been pleted. In developed countries, there are even proposals to build “cities in the air” with thousands of meters of magnitude. With the increase in height and use of light and highstrength materials, windinduced dynamic responses, especially acrosswind dynamic responses of supertall buildings and structures with low damping, will bee more notable. Hence, strong wind load will bee an important control factor in designing safe supertall buildings and structures. Davenport initially introduced stochastic concepts and methods into windresistant study on alongwind loads and effects of buildings and other structures. Afterward, researchers developed related theories and methods, and the main research results have already been reflected in the load codes of some countries for the design of buildings and structures. For modern supertall buildings and structures, across wind loads and effects may surpass alongwind ones. Although researchers have been focusing on the plex problem for over 30 years now, the widely accepted database of acrosswind loads and putation methods of equivalent static wind loads have not been formed yet. Only a few countries have accordingly adopted the related contents and provisions in their codes. Therefore, studying acrosswind vibration and the equivalent static wind loads of supertall buildings and structures is of great theoretical significance and practical value in the field of structural design of supertall buildings and structures. The current paper thus reviews the research situation of acrosswind loads and effects of supertall buildings and structures both at home and abroad. Then, the research results given by us are presented. Finally, a case study of acrosswind loads and effects of a typical supertall structure is illustrated. Mechanism of acrosswind loads and effects Previous researches focused mainly on the mechanism of acrosswind load. Kwok pointed out that acrosswind excitation es from wake, inflow turbulence, and windstructure interaction effect, which could be recognized as aerodynamic damping. Solari attributed the acrosswind load to acrosswind turbulence and wake excitations, considering wake as the main excitation. Islam et al. and Kareem claimed that acrosswind responses are induced by lateral uniform pressure fluctuation due to separation shear layer and wake fluctuation. Currently, the mechanism of acrosswind load on tall buildings and structures has been recognized as inflow turbulence excitation, wake excitation, and aero elastic effect. Inflow turbulence and wake excitation are essentially the external aerodynamic force, which