Study On Distribution Law And Mechanism Of Fault-controlled Landslides

Effect of fault-controlled landslide is the issue which geological and geotechnicalengineering reashers have been concerned but not very well solved for years. The relationshipbetween fault and landslides has always been one of the subject of much interest of scholarsboth at home and abroad. The study on distribution law and mechanism of fault-controlledlandslides has the very vital significance on prevention and reduction of natual disasters andhuman engineering activities such as engineering construction.First, this paper collected a large number of instances about fault-controlled landslides,summarized the distribution law and discussed the cause of fault-controlled landslides.Second, taking Liujiapo Landslide which located in Langao county Ankang city as anexample, survey the geology environmental conditions in study area and the geologicalenvironment background and present deformation situation of Liujiapo Landslide. Last, byusing finite element numerical analysis software MIDAS/GTS to establish athree-dimensional model, then generalize the formation mechanism of Liujiapo Landslide bythe numerical analysis result of both natural state and the seepage state from the aspects of thedisplacement, stress and maximum shear stain.The main subjects drawn from the paper are as follows：(1) the dense secondary fracturewithin deep fault, two or more fault zone intersectant area are the intensive distribution zonefor landslides.(2) the deformation mode of Liujiapo Landslide are: the west side of slope(maximum shear strain) which fault passing through occurred shear failure, and frontal zoneof the slope moved forward, tension cracks occurred in trailing edge(both the maximumprincipal stress and minimum principal stress are tensile stress), thus, driving on thedeformation and destruction of the east side of the slope. When developed a through plane,the landslide occurred.(3) seepage influenced on Liujiapo landslide’s deformation failuremode performanced as follows: slope failure mode of seepage condition is similar to thenatural condition, effect of seepage performances as increases the displacement andmaximum shear strain, as well as the stress difference, that makes the slope failure occurecdmuch more easily.