Comparative analysis of time-series InSAR bridge deformation analysis and structural simulation for a hinged PC bridge

Abstract

This study compares bridge deformation analysis based on time-series InSAR with structural simulation based on finite element analysis for a hinged PC bridge, and discusses the accuracy verification of InSAR displacements. In the past, the steel bars supporting the girder ends of this PC bridge broke, resulting in steps. To efficiently extract the structure-derived InSAR displacements from the limited number of reflection points on the bridge, a temporal displacement modelling method using temperature variation is employed. As a result, the following was found: 1) The SAR vertical displacement per 1 °C on the central span up to three years before the step event was close to the vertical displacement per 1 °C in the structural simulation, 2) In the time-series displacement of the central hinge, a deviation from the simulation results was observed two years before the event, with a gradually increasing trend of sagging.