An Investigation of Damage Mechanism Induced by Earthquake in a Plate Girder Bridge Based on Seismic Response Analysis: Case Study of Tawarayama Bridge under the 2016 Kumamoto Earthquake

Abstract

This paper reports a damage survey and seismic analysis of a bridge. In the first part, the damage survey of some bridges that were affected by the 2016 Kumamoto Earthquake was discussed. Among these bridges, the Tawarayama Bridge, which is a plate girder bridge located very close to an active fault line, was particularly considered. This bridge incurred severe damage because of the earthquakes’ epicenters very close to the bridge. The damage mechanism that can occur in this type of bridge was elucidated. During the damage survey, parts of Tawarayama Bridge were examined to determine the damage in order to examine the factors of occurrence and damage mechanism. In the second part, the seismic responses of Tawarayama Bridge were analyzed using ABAQUS software, and beam elements were applied for the structural members. Firstly, the time-history responses were analyzed using both longitudinal and transverse direction earthquake ground motions separately and simultaneously to investigate the dynamic response of the bridge. Both undamped and damped conditions were considered. For the dynamic response analysis, the recorded earthquake acceleration data of Ozu Station were applied for both undamped and damped conditions considering both east-west (EW) and north-south (NS) directions simultaneously and the damped condition for these directions separately. In addition, a damped model was analyzed by applying design earthquake input data obtained from the Japanese Seismic Design Specifications for Highway Bridges. Consequently, five cases were established for seismic response analysis. Subsequently, the seismic responses of Tawarayama Bridge were investigated, and the behavior of the lower lateral members was examined considering the observed buckling of these members during the damage survey. The field survey and dynamic response analysis indicate that the buckling design of the lower lateral members should be considered in the future design of bridges.

Influence of Lower Lateral Bracing on the Seismic Pounding Damage to Slab-On-Girder Steel Bridges

“…It can be confirmed that it is very inappropriate to ignore the role of the lower lateral bracing when analyzing seismic damage to steel bridges, especially in relation to seismic pounding damage. In previous studies [16,17], the lower lateral bracing was also considered in the simulations, albeit simplified to ancillary components. Simplification of the bracing is generally considered only as beam elements in the finite element model, rather than refined plate elements.…”

“…Zheng et al [15] evaluated the pounding interaction between bridge abutments and steel beams under nonuniform seismic excitation. Aye et al [16] discussed the damage survey of the Tawarayama Bridge affected by the Kumamoto earthquake, especially about its lower lateral bracing's severe damage by the earthquake. Mustafa and Miki [17] found that the bottom plate of the end steel beam will rotate inward under the action of an earthquake and damage will occur at the connection with lower lateral bracing.…”

Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR

“…Nozu and Nagasaka (2017) simulated the rupture processes of the mainshock based on the strong ground motion data and proposed that the slip deficit at a deeper part beneath Mashiki town likely caused the generation of large ground motions. A previous damage assessment of infrastructures conducted by Aye et al (2018) reported bridge collapses at the western Aso flank. By using optical satellite images, a concentration of numerous landslides and soil avalanches were identified around the caldera rim and central cone of Aso volcano (Xu et al, 2018).…”

Numerical simulation on seismic pounding damage in a simply-supported steel bridge

“…In addition, buckling and disconnection of stiffeners and lateral braces appeared. Mya Nan et al [ 8 ] investigated the severely damaged Tawarayama Bridge, particularly the buckling of the lower lateral members, suggesting that the buckling design of the lower lateral members should be considered. Gibe et al [ 9 ] discussed the failure process and limit state of steel bearings in the Kumamoto earthquake, especially under loads in the vertical bridge axis.…”