Comparative fragility assessment of hillside RC buildings under pulse-like ground motions with novel intensity measures

Hillside buildings often experience torsional effects due to uneven foundation height and uneven distribution of mass and stiffness, thereby amplifying the dynamic response of the structures. To accurately evaluate the seismic fragility of hillside buildings, the present study innovatively proposes six novel seismic intensity measures which depend on spectral acceleration and participation mass coefficient of mode. Model analysis of four typical frame buildings are selected to validate and obtain the superior intensity measures. The performance of Practicality, Efficiency, Proficiency, Correlation, and Sufficiency of the intensity measures are evaluated contrastively. The novel intensity measures I W1 , I P and I W2 stand out, and the correlation degree between them and the response of structural displacement and shear force can reach more than 0.9, which become relatively excellent parameters suitable for the evaluation of hillside buildings. In addition to model HB-2, under Rare earthquake, the probability of the other three hillside buildings in Life Safety performance is about 68 %, Collapse Prevention performance is about 9 %, and the maximum probability of collapse is only 0.53 %. The seismic hazard analysis method based on Chinese code presented in current study, which provides substantial reference for fragility assessment under specific site conditions. Further research shows that the more prominent the structural irregularity, the greater probability of the structural damage.