Understanding the Mechanism of Large-Scale Landslides

Abstract

We review recent work on large-scale landslide research that has been carrying out by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, SKLGP. Based on intensive field investigations of large-scale landslides, several failure modes of gravitational and earthquake-induced landslides were proposed, which are widely applied in landslide hazard assessment and mitigation in China. For the gravitational landslides (including the rainfall-induced ones), a locking-section that resists landslide deformation has been commonly observed in many cases. The failure of the locking-section under the natural or human forces often causes the sudden failure of the whole slope, producing large-scale and high-speed landslides. Another failure mechanism “toppling” is not a new term, but the deep-seated large-scale toppling failures have been rarely studied. The slopes composed by anti-inclined lamellar weak strata or weak-hard rock intercalated strata are characterized by this type of failure. The toppling degree and stability are closed related to the strength and thickness of rock strata. The rock strata may experience large flexible bending deformations and failure only occurs when the deformation accumulates to a certain critical value. A deformation zone classification is proposed to assess the deformation stage and degree of toppling failure, which is also a key to evaluate the stability and mitigation of such type of landslides.