Study on Formation Mechanism of Yangjiashan Landslide in Enshi City, China

Engineering geology conditions of Yangjiashan landslide have been investigated and the corresponding geological mechanical model can be established utilizing the remote sensing technique, engineering geological investigation, drilling, laboratory and in-situ test, geophysical exploration, surface nuclear magnetic resonance(SNMR) and monitoring etc. Base on the research presented above, formation mechanism of Yangjiashan landslide is investigated deeper with the engineering geology analysis and numerical modelling method. The results clearly show that: (1)the principal important reason of landslide deformation is that front edge boundary condition change by the erosion caused by rainfalls; (2) the deformation of landslide is resulted from the movement in the front edge of landslide, which is considered as retrogressive landslide; (3) there is impossibility of overall sliding deformation along sliding surface. However, there is possibility of local deformation in some locations due to the steep dip angle of landslide surface. These results lay a solid foundation for decision-making of disaster on prevention and reduction for Yangjiashan landslide as well as the similar landslides in China.