LAUSR

Snowfall is one of the environmental factors that can cause effects on the identification of structural modal parameters. For the steel structure roof of the Harbin Railway Station, effects of snow load to the modal parameters were investigated. A single-span simply supported beam was analysed from the theoretical perspective to study the principles. FEM-based analyses were conducted for the steel structure roof to illustrate the significance of the snow load effects to modal parameters. Uniformly and nonuniformly distributed snow loads were regarded as the essential factors influencing modal frequencies and mode shapes. Monitoring response data are collected and analysed to confirm the accuracy of analytical results. It is concluded that snowfall-induced variations on structural stiffness and mass matrices reduce the modal parameters and alter the mode shapes. The differences between the change regulations of the various modes are closely related to the distributions of snow loads. The theoretical and numerical analytical results are validated to be feasible and credible using temperature, axial strain, and acceleration measurements from the Harbin Railway Station field monitoring system.