The Ms 8.0 Wenchuan earthquake of 12 May 2008 reconnaissance report

Abstract

On 12 May 2008 at 2.28 pm Beijing Time, an Ms 8.0 earthquake occurred in the Wenchuan County of Sichuan province, China. The associated fault ruptured over 240 km on the ground surface. The resulting damage was very severe and widespread, with casualties of almost 70,000, another 18,000 missing and 370,000 injured. The New Zealand Society for Earthquake Engineering reconnaissance team observed the effects and the recovery from this massive earthquake. The team studied the damages caused to the natural and the built environment due to fault rupture, seismic shaking, huge landslides and rockfalls. Maximum shaking intensity of MM XI significantly exceeded design intensity of MM VII for the area. Earthquake induced landslides had a major and catastrophic impact on development and infrastructure in this earthquake. Site selection was demonstrated to be critical. Brittle or non-ductile and irregular buildings performed very poorly especially in a seismic overload situation. Well engineered structures and dams performed well. Lifeline facilities were severely damaged, which resulted in interruptions to key transportation routes, inhibited rescue and recovery operations.