Abstract:

There are a series of landslides developing along Pingding-Huama fault zone. The properties of these landslides are evident. The origin of these lanslides is similar. In fault zone landslide generally consists of one or more secondary landslides. The sliding mass has two layers or three layers, which are composed of deposited loess, strong weathering zone of fault and fault broken zone. The landslides slip along fault strike generally and re-slip time after time historically. According to deformation measurement data in recent years, the landslide is a stage of constant speed creeping deformation at present. The processing of their deformation presents to be creeping to tensile fracture (plastic flow tensile fracture) and then to junior landslide slipping. The landslide formation is in coupling of endogenic and exogenic geological processes that are fault action, earthquake, rainfall and human engineering activity. The long time activity of Pingding-Huama fault provides precondition for these landslides formation. The rocksoil mass characteristics are material basis of landslides activity for ages, while rainfall, earthquake and slope toe excavation are mainly factors that trigger these landslides to lose their stability. Therefore, it is necessary to further study the mechanism of fault zone landslides in coupling of endogenic and exogenic geological processes so as to provide a scientific basis for the prevention and early warning of landslide disaster.

Key words: Bailongjiang River, Pingding-Huama active fault, fault zone landslide, creep, rainfall, earthquake