The Finite Element Method On Loess-slope Stability Analyses

Loess area is one of the places which have more landslides and mud-rock flow problems. Loess-landslides is the specific geology disaster common in the loess plateau. Because of the sensitivity to the water, the shear strength of loess will be reduced sharply when rains for rain-water have infiltrated in loess. Thus cause a lot of landslides and mud-rock flow. As known, one more half landslides happened only because of rainfall. It takes great threat and damage to the people s life and property in the loess region. As our economic construction develop rapidly and the enforcement of the policy of western development, the problem of land-landslide has attracted more and more experts and scholars.Because of the shear strength of loess will be reduced as the moisture content increase, the moisture content becomes a direct factor to the loess-slope stability as infiltrating. So the research on the relation of moisture content and the loess-slope stability becomes extremely necessary.Nowadays, the majority of slope stability analyses take in practice still use traditional limit equilibrium approaches such as circular arc analysis, slice methods and so on. These methods need a lot of assumptions such as Janbus, Bishop and Fellenius, besides the failure surface must be known firstly. Recently, the finite element method is used in slope stability analyses as a widely used numerical analyses method. It has more advantage than other slope stability methods for its accuracy, versatility and fewer assumptions. With the finite element methods, we can calculate the stress and strain and find the weak zone in slope, besides we can get the position and shape of potential failure surface of slope combine with the strength reduced method. So the finite element method is a more ideal method in slope stability analyses.The main objective of this paper is to work out the finite element program which model the process of infiltrating of slope based on the modified Cam-clay model, thuswe can get the distribution of stress and strain within slope;get the shape of failure surface of slope and the safety factor associated with different slope angle and different depth of infiltration with finite element strength reduced method, thus further analyze the failure mechanism of slope when rains and provide some certain scientific reference for practical engineering.