Study On The Characteristics And Disaster Mechanism Of Loess Landslides Of He Tan Village At South Jingyang Plateau

Loess landslide is one of special geological disasters of loess area. It threats to the safety of people’s lives and property, water and electricity facilities, transportation and other industrial and agricultural because of characteristics of frequent, widespread, complexity and catastrophic. The South Jingyang Plateau is located in Shaanxi Province, China. Groundwater level in the loess plateau has been significantly raised since 1976 due to long term artificial irrigation. It changes the hydrogeological conditions of plateau region and results loess landslides occurring frequently, which lead to a huge loss of people’s lives and property, while seriously affecting the development of the region. This paper takes loess landslides of He Tan village at South Jingyang Plateau as an example, through actual field investigation, measurement, exploration and laboratory experiments, analyzed the irrigation model of loess landslide characteristics, formation mechanism and the mechanism. The main research content is as follows:(1) Through the actual field investigation, we obtain the geological environmental conditions in the study area, mainly includes of topography and geomorphology, geological structure, weather conditions and hydrogeological conditions. By indoor test, we studied the composition of loess, physical and mechanical properties and structural characteristics. The backscarp forming mechanism, trailing edge cracks and sink are detailly analysed.(2) On the development characteristics of He Tan village loess landslide has carried on the detailed investigation. It is development and mainly has the following characteristics: sliding suddenly, high-speed, sliding distance, serious disaster, landslide movement to block and wavy surface characteristics.(3) The loess landslides of He Tan village are high-speed distance loess landslides and induced mainly by irrigation. That the study area irrigated loess landslides mainly through three stages: crawling- crack stage â†' slight liquefaction- sliding phase â†' severe liquefaction- slip stage drama. The evolution mechanism of Jiang Liu landslide is analyzed, as a result of the previous slide changed the trailing edge geological conditions and the trailing edge cracks for irrigation water provide good infiltration channel, so landslide happens frequently and has the charateristics of evolution.(4) Using FLAC3 D software simulated the Xi He Tan village loess landslides. Studied on the impact of the slope of rising groundwater level, the maximum shear stress occurs in the saturated soil layer, the soil relative displacement in the vertical when shear failure occurs. Trailing edge had cracks and near the slop foot raised uplift. Slope occur curved strip plastic zone, when the entire plastic zone through the whole soil layer, the slope will cut from the saturated soil layer, leading to slope failure damage. Sliding surface shape and cut export are in conformity with the reality. The numerical simulation is more intuitive to analysis of the influence of the slope of rising groundwater level.