Bedding Landslide Formation Mechanism and Traits in Lesser Khingan Mountain

Abstract

In China’s Heilongjiang Province, Bei’an to Heihe expressway utilizes the original second-class highway to widen and expand for freeway. Subgrade of some sections located at the tailing edge of the landslide, influenced by landform, geological condition and climatic factors are in unstable states, thus poses great difficulty in widening and expansion programs. In the process of this study, the authors identified the space form of the landslide; analyzed the failure mechanism of the landslide; evaluated the stability condition and the development tendency of the landslide; and determined the prevention and treatment measures. This study concentrated on the K178+530 section landslide located on Bei’an to Heihe freeway, and employed field survey, topographic mapping, geological drilling, laboratory tests, numerical simulation, field monitoring and theoretical analysis methods to carry out integrated study of the failure mechanism of the landslide. Study results show that the K178+530 landslide belongs to translational landslide, rupture surface is located at the bottom of sub-grade spoil and silty clay; during survey, the landslide is in the limit equilibrium state, directly affects the stability of sub-grade slope; atmospheric precipitation, snowmelt water and seasonally frozen soil thawing water provide a continued water source for landslide, surface water and ground water supply the Quaternary pore water by infiltration and lateral runoff through surface cracks and shallow high permeability rock and soil, low permeability rock and soil under the loose overburden form aquiclude, rock and soil of the aquiclude are saturated to be soften form rupture surface; the landslide have seasonal, gradual, low angle characteristics.