Analysis of Seismic Performance of Suspension Bridge in Myanmar

After the collapse of Myaungmya Bridge in April 2018, the safety of infrastructure became an urgent task and attracted increased public interest in Republic of the Union of Myanmar. After the incident, monitoring systems were installed in several suspension bridges, of the same structure type as Myaungmya Bridge, recording unwanted bridge movements. The observations indicate that a large deformation occurred, rendering the current bridge condition different from its original design, though the safety of the current condition is unclear. Therefore, in this study, numerical models are simulated utilizing the data from detailed observations made by the monitoring system, to confirm the safety of the bridge. Twantay Bridge was chosen as the bridge analysis target. Linear time history analyses were performed on Twantay Bridge, in which the seismic performance was evaluated by comparing the stresses generated in the main members with the allowable stresses. Moreover, by comparing the analysis results obtained from two models – a design drawing model of the Twantay Bridge, and a model that reproduced the present condition of the bridge – the current bridge performance was confirmed. The information obtained from this analysis is useful in the field of maintenance and will allow Myanmar officials to effectively plan and take corrective action for the requisite maintenance of the damaged bridge.