Study On The Background And Disaster Modes Of Landslide On Loess Plateau

Loess plateau, with special structure, landform and strata, is one of the areas where geological hazards occur frequently. The paper herein studies the development background, inducing factors and failure mode of landslides in loess plateau.After studying the landslide type, distributions, geological conditions, geographical environment, the paper summarizes the forming factors, controlling and inducing factors of landslides in loess plateau, obtaining 8 kinds of failure modes. For each kind of failure mode, selecting typical landslide case to analyze it’s mechanism and kinematics simulation.The loess plateau is located in the composite part of the North China platform and the Tibetan fold uplift belt. In the plateau there are complicated tectonic framework such as differential settlements, tension and extrusion due to the modern tectonic activities. These areas Liupanshan, Ziwuling, Huanglongshan uplift intensively. Fen-Wei graben belongs to modern rift zone. Longzhong, Tianshui, Longdong and most of Shanbei area are the sedimentation basin in Tertiary and smoothly lift in the Quaternary. These tectonic activities control the loess landform and types of landslide disasters.The landform of loess plateau includes mountain, loess platform tableland, loess beam, loess hill, plain, basin, desert etc. The landform affects the type of landslides, and it is one of the main controlling factors of loess landslide. It lays a foundation for studying the landslide disasters in loess plateau from historical and causative perspectives by studying the tectonic structures and landforms of loess plateau.There are three types of slope according to its material, namely soil slope, rock slope and composite slope. Slope types determine the type of landslide disaster. Therefore, there are correspondingly three types of landslide, namely internal loess landslide, loess-rock interface landslide and loess-rock landslideFactors inducing landslides are surface water, groundwater, river erosion, human engineering activities, freezing and thawing, weathering, geotectonic movement and earthquake. Water and groundwater includes infiltration, irrigation and reservoir. Human engineering activities include stack, excavation, mining and extraction of groundwater. Different factors will induce different landslide.The landslide of loess plateau can be classified into 8 modes based on the stratum and motion characteristics, including high-speed remote landslide model(Dongfeng landslide), rapid falling mode(Sanmutai landslide), creep of deep layers mode(Yanlian landslide), creep of shallow layers mode(Luoyugou landslide), high speed remote landslide on the mudstone layer(Saleshan landslide), high-speed landslide-debirs flow on the mudstone layer(Dagou landslide). The factors for each failuer mode are stratum, slope structure types, and triggering factors. For 8 kinds of model, selecting typical case then analysis the mechanism and kinematics simulation.