Thermal actions on bridges

摘要

The European Committee for Standardisation (CEN) develops a system of new building standards for construction works (Eurocodes) which based on a new safety concept. This concept requires careful assessment of safety and reliability in structural design. The probabilistic approach realised in the paper, corresponds to this safety concept given in the Eurocode 1, ENV1991-1 "Basis of design and actions on structures". The influence of climatic actions (air temperature, solar radiation) on the temperature profile in concrete bridges is considered. The representative values of thermal actions (the uniform temperature component and the linear temperature difference) are determined by means of the representative values of climatic actions. The last ones are obtained with the help of statistical analysis and the theory of extremes. The combination factors Ψ, used in the different load combinations, are also calculated. The results are included in the pre-standards ENV1991-2-5 "Thermal actions" and ENV1991-3 ,"Traffic Loads on Bridges".