Dynamic formation mechanism of landslide disaster on the Loess Plateau

Landslide disaster is a major geological problem that threatens the safety of people's life and property, and the construction and operation of towns and major projects on the Loess Plateau. Aiming at the dynamic formation mechanism of landslide on the Loess Plateau, based on a large number of investigation, statistics, tests and theoretical analysis, following conclusions were drawn: The regional tectonic stress is the main driving force for high occurrence of landslides. It is the controlling factor for landslides ocurring in different zones and belts and the first internal cause. The tectonic stress of the slope not only creates the structural surface, but also continuously alters and loosens the structural surface and dismembers the integrity of the slope. It is the main driving force for the formation of single landslide and the second internal cause of loess landslide. Loess is a kind of special structural soil with strong water sensitivity, which is prone to disasters under soil stress drive. This disaster-prone property of loess is the internal cause of soil disaster and the third internal cause of loess landslide. A large number of landslides are related to water. Surface water penetrates into the shallow surface of loess in large quantities, which will cause shallow surface collapse and sliding disasters. When water enters the deep loess along the micro, fine and macroscopic dominant channels, it may cause deep-seated landslides. Thus, the seepage of dynamic water is the major external cause of loess landslide. Construction disturbance will not only change the original stress state of slope, but also expand and loosen the existing structural plane. Nowadays, construction disturbance has become an important geological agent to induce geological disasters and is the secondary external cause of loess landslide.