EAAI Journal 2026 Journal Article
Seismic fragility assessment of curved girder bridges under vehicle-induced risks: A specialized deep learning-based neural network approach
- Wei-zuo Guo
- Wei-you Guo
- Yan Gong
- Shu-mao Qiu
The special horizontal alignment of curved girder bridges often leads to higher seismic demands than those of straight bridges, resulting in greater seismic fragility. With the continuing growth in transportation and logistics demand, the likelihood of heavy vehicles being stranded on bridges during earthquakes further increases, amplifying the seismic risk of curved girder bridges. However, existing data-driven seismic fragility assessment methods generally neglect the additional risks introduced by vehicle loads. Therefore, this study develops a specialized deep learning model—the seismic fragility embedding neural network under vehicle-induced risks for curved girder bridges (SFENR)—to assess their seismic fragility under combined vehicle–earthquake effects. An automated parametric finite element (APFE) program is developed to efficiently simulate the vehicle–curved girder bridge system and batch-produce nonlinear dynamic responses, thereby providing essential data support for training the SFENR model. A case study is then conducted on a typical three-span continuous curved box girder bridge to systematically investigate how vehicles with different weights and positions affect the seismic fragility of bridge components. The results demonstrate that the proposed SFENR model substantially outperforms conventional neural networks in terms of both memory efficiency and prediction accuracy. Specifically, the SFENR achieves a nearly 50% reduction in memory usage while improving Accuracy by 2–10%, with both Precision and Recall consistently maintained above 70%. Furthermore, the fragility curves of structural components exhibit greater sensitivity to variations in the tangential rather than radial positions of vehicles on the bridge deck. The presence of vehicles induces a non-monotonic effect on the seismic fragility of curved girder bridges—meaning that vehicles increase fragility at lower ground motion intensities but reduce it at higher intensities. This highlights the importance of considering vehicle effects in seismic risk evaluation and advances the development of more reliable fragility assessment for highway bridges.