ABSTRACT
In mountain and submontane regions of Uzbekistan it is revealed about 2 thousand sliding sites, displacement of landslides is fixed 8181 cases. Thus, 77% of landslides developed in loess and sandy-clay soils, 23% in clays. The landslides caused by snow melting, rainfalls and ground water-65%, historical and modern earthquakes 20-25%, technogenous factors 10-15%. Mud flows in mountain regions of Central Asia, widespread in loess soils, occur in reach water years, are the most dangerous, are suddenly formed, movement occurs some minutes with high speed of displacement and the large extending. Places of formation of landslides are connected with modern and ancient covered depressions in which there is movement of ground waters. In nature of destruction of loess soils depending on conditions of a local watering of slopes and the reasons of the beginning of the starting mechanism of landslide are selected three aspects of their strength loss: underground washout, tixotropic liquefaction and shattering.
