Analysis And Assessment Of The Stability Of Loess Landslides In The WuDing Highway

China’s highway gradually extends to the mountainous regions, which not only optimize the structure of the local area transportation, but also effectively promoted the economic development and social progress. However, the negative effects of highway in loess areas in western China are increasingly prominent. The negative effects of highway destroy the regional ecological environment and the natural human landscape, at the same time, which also affect the safety of its operation. The 16 loess landslides along the WuDing highway as the research object, through analyzing the characteristics of the landslides, the stability influence factors and formation mechanism, getting some results:(1) Proposing the classification scheme of the loess landslides along the WuDing highway: the landslide of loess strength control type, the landslide of sand-mudstone strength control type and the landslide of red-clay strength control type.(2) Getting the development rules of the loess landslides along the WuDing highway:(1)The loess landslides along the WuDing highway are mainly for the landslide of red-clay strength control type;(2)The landslides are closely related to Luohe river valley or loess gully,the landslides develop on both sides of Luohe river valley or loess gully, and the main development in the left bank;(3)The landslide type of loess gully development is mainly for the landslide of red-clay strength control type, the both sides of Luohe river valley develop three types of landslides;(4)Most landslides occur in the slope between 30°~50° of slopes;(5)The landslides occur mainly in the slopes that aspects are in the northeast and southwest;(6)The landslides elevation is mainly in between 1300~1550m.(3) Proposing the lateral erosion-cracking mechanism of the loess landslides along the WuDing highway: lateral erosion the bank-collapse and migration-drop under the action of gravity-the back cracking-sliding.(4) Combined with case studies, using qualitative analysis, limit equilibrium method and Geo Studio numerical simulation method to comprehensively assess the stability of 16 loesslandslides, getting the steady state rules of the loess landslides along the WuDing highway:(1)Under the conditions of weight and weight+heavy rains, the landslide of sand-mudstone strength control type is mainly for steady state;(2)the landslide of red-clay strength control type is mainly for metastable state under the condition of gravity, and it is mainly for unstable state under weight+rainstorm state;(3)The stability coefficient of the loess landslides along the WuDing highway is reduced by 7%~14% under the condition of rainfall. And on the basis of the stability of 16 loess landslides, the study area is divided into unstable-basic stability region and stability region.