Study On Formation Mechanism And Movement Process Of Large Loess Landslide

Landslide is one of the loess slope region one of the most rare geological disasters， Andone of the most serious disasters what cause casualties。In our country, a wide range of theloess plateau is pregnant with many large loess landslides. With the enhancement of humanengineering activities, as well as the frequent rains in recent years, landslide disaster has beenbecoming serious.The two landslide in the text located in Zizhou County of Shaanxi Province,which aretypical loess landslides. Landslide in Lao Jun Dian occurred in three stages,and the sizesreduced in turn. There are different degrees of cracks on landslide mass. Foreland has beencreeping, and presents the growing trend, threat the farmland and spillway before the slope;Former of Xi Gou landslides appear some cracks on both sides of the slope, the stability ispoorer. Slump happened on the foreland during the survey period, and destroyed the cementroad.Taking the above two landslides for example, the text analyzed geological environmentcondition in what loess landslide formation happened, and on this basis analyze factors,sensitivity,what affect the stability of the landslide; Through the finite element method (fem)simulation, analyzes the formation mechanism of the landslide; to simulate the movementprocess of landslide by discrete element method; Finally, we get the best treatment plan to thetwo landslide based on comprehensive fuzzy evaluation.Following are the main results of thetext:(1)By analysissing the reasons why the landslide happened,the landslide was caused bythose factors,like internal friction angle,cohesion,groundwater,slide weight degree and load.Then we know that the groundwater is the most sensitive factor by sensitivity analysis.(2)Using the finite element method and geo-slope software,the text established the modelof the slope in Shi Pan flute of Lao Jun Dian town without sliding.sets up slope (old stonetemple side ditch landslide sliding three periods of time in front of the slope model,calculating stress and displacement of landslide, the forming mechanism is analyzed, the maximum shear stress of slope body and focus on the stratigraphic boundary, and inside theslope on a convex tendency; X-displacement from the toe to the top in turn decreases, and thedisplacement contour and nearly vertical slope; Xi Gou landslide is due to the slope foot longbefore the lateral erosion to gradually become steep slope toe, slope maximum shear stresscontour nearly parallel to slope surface, local convex upwards. Focus on the most obvious inthe maximum shear stress in the slope body part, in the upper slope body also has the obviousconcentration; X direction displacement and slope nearly parallel to slope surface, slightlyconcave, displacement, surface displacement, the largest and situated in smaller and smaller.(3)Using the discrete element method and2d-block software,the third sliping of thelandslide in Shi Pan flute of the Lao Jun Dian town went through four stages:the starting stage,accelerated movement stage, decelerated motion stage and stop sliding-slide bodyaccumulation stage;the landslide in Former Xi Gou of the Huai Shu Cha town went throughfour stages:the starting stage, accelerated movement stage, decelerated motion stage and stopsliding-the back of slide body accumulation stage.(4)According to the characteristics of the two landslides,the author set three controldesign schemes for each one.Using the entropy multi-object decision method,the besttreatment plan of the landslide in Shi Pan flute of the Lao Jun Dian town is Anti-slidepile+Drainage ditches and Gutter+Blind ditch+Simple observation；the other one is Anti-slidepile+Drainage ditches and Gutter+Water collecting well+Three-dimension vegetationnetwork+Observation by Setting up sites.