Performance Assessment Using Structural Analysis and Spatial Measurement of a Damaged Suspension Bridge: Case Study of Twantay Bridge, Myanmar

Abstract

A performance assessment of the Twantay Bridge, Myanmar, which is a suspension bridge that has been damaged by the movement of anchorages due to the soft soil conditions, was conducted based on simple monitoring, spatial measurements by three-dimensional (3D) terrestrial laser scan, and structural analysis with the finite-element method (FEM). Simple monitoring can capture the present progress of main-tower inclinations. This study proposes a method for capturing the overall deformation of bridges based on spatial measurement by 3D terrestrial laser scan. The FEM analysis was able to appropriately reproduce the deformation history of the suspension bridge after the construction, which was caused by movement of the anchorage blocks. Thus, the deformation of the main towers obtained with FEM was found to almost agree with that measured by the 3D terrestrial laser scan. In addition, by giving external loads, ultimate capacities were evaluated. This study clarified that a combination of simple monitoring, spatial measurements by 3D terrestrial laser scan, and structural analyses by FEM is useful for the safety assessment of and maintenance strategy for damaged suspension bridges.