The Effects of Earthquakes on Rock Slopes

Many recent earthquakes caused many large scale rock slope failures, some of which are wrongly named as landslides. The scale and the impact of rock slope failures are very large and the form of failure differs depending upon the geological structures of slopes. First the author describes some model set-ups and experiments to investigate the effects of shaking or faulting due to earthquakes on rock slopes. Then fundamental characteristics of the rock slope failures induced by the earthquakes are described and evaluated according to some empirical and theoretical models. Furthermore, the observations for slope failures in relation to earthquake magnitude and epicenter distance were compared with several empirical relations available in literature. Some of major rock slope failures induced by earthquakes are selected and the post-failure motions are simulated and compared with observations. In addition the effects of tsunamis on rock slopes are explained through the recent mega-earthquakes and are discussed.