Analysis On Genetic Mechanism And Stability Of The Chigou Landslide

According to the loess-red beds interface lanslides in such typical loess landslides, relying on the EHV transmission line project, the Chigou landslide located in Changhe town of Tongwei county was studied. The development characteristics of the landslide were identified through drilling, geophysical, reconnaissance and the other technique methods. The forming reasons and influencing factors were analysed, and the evolution mechanism of the landslide was investigated. The stability in current state and the stable state under the influence of transmission project were analysed based on qualitative and quantitative methods. The thesis aims to provide a scientific basis for project location and design, and provide a reference for research on similar landslide and engineering applications.The main research results as following:(1) The structure of "double heterostructure" form by loess and red layers, rain and earthquakes are the main causes of the landslide. The loess with poor permeability and the red beds with good permeability all belong to the easily-sliding strata, the seasonal rainfall and frequent earthquakes are the major factors, the erosion of river and the human activities such as are secondary factors.(2) The status of landslide formed through loess-red beds interface sliding repeatedly of the original slope. The landslide slide along the loess-red beds interface almost which with the anti-dip beds and gentle slope angle, some are loess-red beds cutting layer landslides in the local. The irregular shapes posterior wall and tall scarps and other features formed under the influence of sliding repeatedly and natural erosion prolonged.(3) The stability of the landslide with transmission line project is better overall. Stability under influence of the project is worse compared with it in the natural state, and some slopes prone to collapse in steeper parts, there may be slide again under the influence of storm or earthquake, etc. The stability of the project will improve when the base of the project is located in red beds.