Predominant Direction and Mechanism of Landslides Triggered by Lushan Earthquake

Based on Lushan earthquake records, drainage systems and 1 754 earthquake-induced landslides, control factors of the directions of landslides triggered by earthquake were researched. The dominant direction of landslide number and the dominant aspect of natural slopes were compared; the direction of new tectonic stress field in the Lushan seismic area was determined from the antagonism principle; the certainty factor for landslide in each sub-area was determined by GIS spatial analyses. The research shows that the predominant direction of natural slopes is a control factor of the directions of landslides triggered by an earthquake, but the asymmetry of mountain slope landform should be considered; the direction of new tectonic stress field is a global factor of the directions of landslides; the direction of the maximum cumulative acceleration at a seismic station also control the sensitivity directions of landslides in the station area; to an earthquake resulted from a blind fault, it may be a universal law that the above three factors control the direction of earthquake-triggered landslides.