Seismic loss assessment for regional building portfolios considering empirical seismic vulnerability functions

Assessing the actual seismic economic losses of regional building portfolios is essential to quantify the seismic resilience of urban and rural areas. Various building clusters indicate different damage levels under real earthquakes of different intensities, which directly leads to apparent anomalies in the actual economic losses of various building portfolios. This paper proposes an economic loss assessment model for large-scale regional building portfolios, considering the damage probability matrices. The traditional empirical vulnerability quantification method is optimized and updated by combining the analysis methods of probability risk, reliability, macroseismic intensity, and instrument intensity. Five typical building sample sets (total survey area: 56,937.1893 × 10⁴ m²) of 57 typical cataclysmic earthquakes that occurred in Yunnan Province, China, from 1993 to 2022 are collected and processed, and an updated fragility dataset is established. The calculation model considering empirical structural vulnerability and economic loss quantitative parameters is innovatively developed. Combined with the quantitative approaches of the multidimensional nonlinear fitting model and the established regional empirical structural vulnerability database, the seismic loss evaluation model of large-scale regional structures is established. Ultimately, the earthquake loss point cloud and matrix of typical building portfolios in the large-scale zone are developed using cloud analysis and the proposed seismic loss evaluation model.