Comparative Study on Temperature Actions in Structural Design Codes

Temperature action is a primary environmental load that infrastructure endures during long-term service, and it is also one of the key causes of structural performance deterioration. With global warming and the increasing frequency of extreme weather, the temperature actions on structures are becoming increasingly complex and severe. Whether current design codes can adapt to environmental climate changes, particularly regarding how to effectively respond to the impact of extreme temperatures, has become a critical concern in engineering. Based on the current structural design codes of major countries and regions (including China, the United States, New Zealand, Japan, Europe, and Hong Kong, China), this paper reviews and analyzes their calculation methods and specifications of temperature actions. The basic temperature definitions and thermal parameter selection for building structures of Chinese and European codes are compared. The requirements and distinctions regarding uniform temperature and temperature gradients in bridge design codes are analyzed. The temperature distribution characteristics for tower structures under complex solar radiation are explored. The differences in the selection of partial factors and combination values for temperature actions under the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) are discussed. The study reveals that each code possesses distinct characteristics in terms of theoretical depth and engineering application. The European code establishes a refined non-linear temperature gradient model covering buildings, bridges, and towers, emphasizing the physical mechanisms of load effects and their actual engineering impact. The American code adopts a more scientific approach in limit state design by distinguishing between displacement and force effects and assigning different partial factors accordingly. The Hong Kong code (SDM), based on meteorological measurements and prediction data, has upwardly adjusted design temperature differences in response to global warming. The review and analysis of temperature actions can provide a reference for the practical application and improvement of codes in various countries, as well as an important technical basis for project owners, design units, and operation and maintenance management departments.