Analysis of the Seismic Vulnerability of Buildings in the Lushan M_s7.0 Earthquake in the Sichuan Province of China

This study is carried out based on field investigation data obtained over more than 20 days after the 20 April 2013 Lushan M_s7.0 earthquake in Sichuan Province, China. The investigation includes detailed seismic damage data from 3,684 buildings in 428 districts. This research summarizes the seismic characteristics of buildings with different structures in this area and systematically analyzes the cause of damage. Based on this analysis, the seismic vulnerability of various structural forms in different intensity regions is systematically assessed. The damage characteristics are summarized for several types of the structures typical in the region: constrained masonry structures designed following current standards, unengineered constrained masonry structures, unreinforced masonry structures, brick-wood structures, brick-concrete structure, traditional Chinese timber frame structures, reinforced concrete frame structures, tall buildings, and industrial plants. Moreover, the causes of damage to these structures are investigated. Furthermore, through statistical analysis, this study develops a vulnerability matrix for the main building types and compares their vulnerabilities of similar buildings in regions with different earthquake intensities. The research results provide an important reference for earthquake engineers to recognize failure modes in different types of structures (especially those reconstructed after the Wenchuan earthquake, Sichuan Province, China), revise seismic design codes, and formulate future disaster-reduction plans.