Study on the vertical temperature gradient model of tied-arch bridge in alpine region

The temperature effect is one of the main causes of structural cracks and other damage in bridges. There are no temperature gradient patterns and recommended values for bridges in different regions. The temperature gradient model and its recommended value in China’s General Specifications for Design of Highway Bridges and Culverts (which references the American Association of State Highway and Transportation Officials’ LFRD Bridge Design Specifications) are not divided by geographic location. Based on field temperature test data and 50 years of meteorological data from the Qiqihar tied-arch bridge, a thermal conductivity model of the temperature field is established using the finite-element analysis method. The vertical temperature gradient model and its recommended value for a 100-year service life in alpine regions are determined. The model parameters are rigorously grounded in the statistical range of observed regional climate data, ensuring the fundamental validity and local representativeness of the model. The rationality of the findings is verified by comparing with the specifications of China, the United States and Japan, providing a technical support for engineering applications in alpine regions.