GENESIS MECHANISM AND STABILITY ANALYSIS OF THE XIAOHELONG LANDSLIDE IN YANJI CITY

Since the planning of a road expansion at the front edge of the Xiaohelong landslide, it is necessary to conduct an analysis of its genesis mechanism and evaluate the stability of the landslide with a view to preventing it from posing a risk to the safety of the proposed road and pedestrians. This paper carried out a detailed geotechnical investigation to clarify the engineering geological conditions within the survey area of the Xiaohelong landslide, and analysed the factors affecting the formation of the landslide as well as the deformation process. After that, this research employed FLAC^3D software to make an analysis of the stability of the landslide under either natural or rainfall conditions on the basis of strength reduction theory. The research indicates that:1) The influencing factors of the Xiaohelong landslide consist of internal factors such as topography and geomorphology, stratigraphic lithology, together with external inducing factors such as meteorological conditions and human engineering activities. 2) The research area is originally a natural side slope of forest land. However, due to the manual excavation, the right side of the slope collapses and gradually destabilizes over time, resulting in a landslide. Simultaneously, the rear edge of the slope on the left side produces scarps and cracks, which, together with the the excavation of the front edge, causes the rear part to lose support, forming a traction landslide. 3) By evaluating the stability of the landslide, this research obtains the landslide stability form, the slope strain distribution law and the slope deformation law. According to the calculation, the safety coefficient under natural conditions is 1.1 while that under rainfall conditions is 1.08, both of which are ranging from 1.05 to 1.15 with metastable state. The results of this paper can provide reference for the analysis of the genesis mechanism and stability evaluation of analogous landslides.