Characteristics of landslides induced by Wenchuan M_S 8.0 Earthquake and preliminary analysis of their relations with ground motion parameters

The MS 8.0 Wenchuan Earthquake,which occurred on May 12th,2008,induced large scale landslides which distributed across wide areas and caused great losses in both economy and casualty.Landslides triggered by Wenchuan Earthquake are obviously affected by the fault and distributed asymmetrically on the two sides of the fault.Analysis shows that the landslides triggered by Wenchuan Earthquake have some relation but not a definite relation with the earthquake intensity.However,there does exist an obvious relation between these landslides and earthquake magnitude or peak ground acceleration (PGA).A basic analysis on the relation between earthquake-induced landslides and PGA parameter is given on the basis of the near 40 groups of records distributed along the Longmenshan faults.The conclusion is:there exists a normal relation between earthquake induced-landslides and PGA;the stability of the slopes is affected more by the horizontal records of the ground motion;and there is a 0.2g boundary among the PGA records with which greater PGA causes more landslides around the Longmenshan faults and its neighbourhood.The results demonstrate that it is useful in both theory and practice to study earthquake-induced landslides with PGA.