Impact of cumulative damage on fragility of rc framed buildings subjected to earthquake-induced landslides

Numerical studies and field missions have shown that seismically-induced slides and rock falls are secondary events of earthquakes with very high destructive potential. In many cases, the loss induced by the landslide phenomenon has significantly exceeded the impact of earthquake shaking Recent studies proposed fragility models for 2D reinforced concrete (RC) framed buildings on the crest of the slope subjected to slow-moving landslide. In this paper, a new fragility model is proposed for RC framed buildings located downstream of the slope, and hence subjected to landslide impact loading. A two-storey structure, which was designed only to gravity loads, was selected as case study. According to Monte Carlo simulation method, one thousand realizations of the structure were randomly generated by considering uncertainties on both landslide parameters and structural properties. The peak ground acceleration was chosen as intensity measure (IM) for earthquake ground shaking, whereas the landslide impact velocity was selected as landslide IM. The novelty of this paper includes the consideration of (i) the uncertainty on landslide width and impact angle, and (ii) damage accumulation due to earthquake shaking and landslide impact. Both the generation of random load-capacity models and post-processing of analysis results were performed in Matlab, whereas sequential structural analyses were carried out with OpenSees. The inter-storey drift ratio was assumed as engineering demand parameter and two limit states were assumed, producing as many fragility curves of the structure.