Reconnaissance report on buildings damaged during the Lushan earthquake, April 20, 2013

At 8:02 am on April 20, 2013, an earthquake with a magnitude of seven on the Richter scale occurred in Lushan County, Sichuan Province, China. This paper describes the investigation of the damage to buildings in quake-hit areas. By comparison with “5.12” Wenchuan earthquake that occurred in the same region 5 years ago, the damage modes of the buildings have been analyzed. Public buildings, most of which were reconstructed after the Wenchuan earthquake, exhibited a good performance in regard to the main structures. However, severe damages were identified from non-structural elements. The performance of frame structures supported on rubber isolators was examined, and very few cracks from the infilled walls were observed, unlike the other frame structures. Rural housing suffered extensive damage during this earthquake, due to inadequate structural systems for horizontal-force resistance, lack of construction supervision, and insufficient ground treatment, all of which lead to the tragic destruction. Conclusions were given by presenting several suggestions to enhance the seismic behavior of rural housing.