Temperature field of long-span stiff skeleton arch bridge subject to temperature variation

Temperature variation causes thermal deformations and stresses in bridges, thereby compromising the safety and comfort of bridges and trains. This article focuses on the temperature field of a long-span stiff skeleton arch bridge in the steep valley area of Sichuan-Tibet Railway. Finite element models were established and calibrated using field data measured from a meteorological station. The model incorporated uneven thermal boundary conditions and was utilized to predict temperature fields within the bridge. Daily temperature variation laws were derived under seasonal working conditions. Results showed that deformations caused by transverse temperature gradient are predominant compared with deformations caused by vertical temperature gradient. Temperature gradient models were developed from the daily temperature field of the arch ring of the bridge. The temperature gradient results from the proposed model were validated using relevant codes. The outcomes of this research provide useful tools for the design of bridges subjected to large temperature variation.