Abstract:A Ms. (surface wave magnitude)6 .0 earthquake occurred on September 16th, 2021, and affected 18 towns in Luxian County, Sichuan Province with different impacts. Through an on-site survey, we quantitatively analyzed the damage of the earthquake to residential houses in affected areas, assessed relationships among the house structures, epicentral distance, and degree of residential damage. This led to the development of a matrix of residential housing vulnerability to show the earthquake-affected areas in the Sichuan Basin with different intensities. Based on this analysis, the study compared the difference in average earthquake damage indexes between the affected areas and other regions that had previously experienced earthquakes of the same magnitude. In doing so, we were able to identify some of the key characteristics and factors that contributed to the degree of housing damage observed in the study areas. The following results were drawn: (1) housing vulnerability ranked from high to low involving brick-concrete structure, brick-wood and other structures (civil, wood and stone masonry structure), steel-concrete structure; (2) the areas within 6,600 meters from the epicenter experienced 90% of the earthquake damages; (3) earthquakes of similar magnitude cause 1~2 times less damage to residential housing within the Sichuan basin than areas in the mountainous regions. The results herein can be used as scientific references for the rapid assessment of damages, planning, and reconstruction of residential housing in the post-earthquake period in the Sichuan Basin and other settings prone to earthquakes .
