Kota Dobashi, Yuichi Ito, Kouichi Takeya, Eiichi Sasaki

Abstract: Movable bearings are expected to respond to bridge expansion and contraction due to temperature changes and train loads. However, due to the friction within a bearing, actual bearing movement tends to be smaller than theoretical prediction. This discrepancy between actual situation and theoretical evaluation can suggest that girder expansion or contraction is constrained, thereby causing stresses and frictional reaction forces at the bearing seat. Although bearing friction is expected to increase with age, there is no standardized method for evaluating the friction coefficient, making it unclear when preventive maintenance actions should be implemented. This study aims to estimate the friction coefficient of bearings in actual bridges using finite element method (FEM) analysis and field measurements. The measurements have revealed a characteristic behavior whereby the bearings initially stick and then slip. This bearing behavior was then reproduced using numerical simulation, demonstrating the feasibility of estimating the friction coefficient of movable bearings under in-service conditions.

Keywords: Bearing Friction, Friction Coefficient, Bearing Behavior, Temperature Change.

Date Published: December 22, 2025
DOI: 10.11159/ijci.2025.023

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