Generation of Seismic Fragility Curves for RC Highways Vulnerable to Earthquake-Induced Landslides Based on ICT

Abstract

In steep terrains, major highways are laid along steep slopes that are vulnerable to slope failures. More often than not, such mountainous regions tend to be seismically active. Structures located in steep slopes are vulnerable to earthquake-induced landslides and affect the integrity of the highways. We analyze two major landslide events that disrupted major highways in the past and generate fragility curves to estimate the hazard in such a scenario. We derive the curves based on landslides that damaged the highway by measuring the distance from the source of rockfalls. Our results indicate that the RC within 3–5 m from the crest of a landslide tend to be at a greater risk. In an event of higher magnitude, the fragility curves estimate lower probability of damage. This could be because the shaking itself causes enough damage than the triggered landslides. It was also observed for a distance of 10 m from a slope crest in a low-magnitude earthquake, the damage is the most. This shows that the momentum of the triggered rockfall increases due to increased distance and causes substantial damage on the RC highways. Damage caused by Taiwan rockfall event which occurred in April 2019 was assessed using these curves and was found to be moderate. Fragility curves generated in this study can be used to estimate the damage in a future scenario where there are highway constructions along slopes that are prone to rockfalls.