Investigation of civil building damage and its spatial characteristics under 2019 ML6.0 Changning earthquake

Abstract

An ML6.0 earthquake occurred at 22:55 on June 17, 2019, in Changning County, Yibin City, Sichuan Province, China. The Changning earthquake killed 13 people and affected an area of 3075 km2. The disaster caused by the earthquake is mainly the damage of civil buildings in the affected area. A field investigation on civil building damage was conducted by the authors after the earthquake occurrence. The destruction forms and damage area of civil buildings in 44 villages from different seismic intensity regions were collected and it was found that there are significant differences in the severity of building damage of different structure types. In order to analyse the spatial correlation between building damage and influencing factors, nine indicators are selected including structure type, PGA, elevation, slope angle, population density, per capita GDP, distance to river, distance to fault and NDVI, and damage ratio is defined to measure the degree of building damage in each village. The spatial correlation between civil building damage and influencing factors is analysed in GIS using histogram statistics and correlation analysis. The results show that PGA has the strongest correlation with civil building damage. In the area with greater seismic motion, the civil building damage is more serious. Structure type and economy level also have significant linear relationship with building damage.