A probabilistic approach for performance-based assessment of highway bridges under post-earthquake induced landslides

Abstract

The seismic vulnerability of reinforced concrete (RC) highway bridges in the vicinity of landslides is usually evaluated without considering the impact of sliding mass flow-type. The paper presents a probabilistic approach for assessing the performance of highway bridges under combined ground shaking and earthquake-induced flow-type landslide. This approach combines the displacement-based hazard analysis of the landslide, the modified Cloud method for considering the effect of post-earthquake induced landslide and the development of fragility curves for bridges. Firstly, the slope displacement and instability probabilities under ground shaking were obtained based on the intensity levels of the bridge site. Then, the velocity of the flow-type landslides at the bridge site was estimated by the computational fluid dynamics theory, which was adopted to compute the impact force on the bridge columns. The impact of the flow-type landslide was included in the modified Cloud analysis by utilizing Monte Carlo simulations and the logarithmic polyline-based regression. Finally, seismic fragility curves of the RC highway bridge subjected to seismic loadings and landslide impact forces were derived with the consideration of various sources of uncertainty, including the aleatory variability on the material, geometry, structural demands and capacities. The proposed approach was illustrated by a typical RC highway bridge under both the earthquake and landslide hazards. The importance of considering the seismic-induced flow-type landslides on bridge vulnerability is highlighted. •A probabilistic approach was proposed for bridges under impact of earthquake-induced landslides; •The impact of landslides was included in Cloud analysis by Monte Carlo simulations; •The logarithmic polyline-based regression was adopted for establishing EDP-IM relationship; •Various uncertainties of earthquakes and landslides were considered in fragility analysis of bridges.