Multi-hazard vulnerability of code non-conforming RC buildings under earthquake followed by cascading landslide

Earthquakes can trigger landslides in unstable slopes leading to a sequence of loading in structures. Although seismic vulnerability and landslide vulnerability are considered in many analyses, cascading multi-hazard analysis is not commonly reported in the existing literature. Thus, to replicate the more realistic scenario of multi-hazard cascade, earthquake only and earthquake and triggered landslide vulnerability analyses of representative code non-conforming reinforced concrete (RC) building are performed. Aggravation due to the post-seismic occurrence of landslide debris is quantified for both bare and infill frames. Fragility functions are developed for single and multi-hazard scenarios for bare and infill frame cases. The results reflect that infills can effectively control displacement, which signifies the beneficial effects of infills. It is concluded that the static loading (height of debris) is more sensitive for bare frames, whereas dynamic loading (velocity of flow) is more sensitive for infill frames. The sum of findings highlights that the effects of cascading hazard would be prominent basically at stronger ground shaking rather than the code recommended shaking scenarios.