Optimal Design Of Anti-slide Pile And Finite Element Analysis Of Landslide Prevention

Slope failure is one of the most popular styles of nature disasters, It often happens with earthquakes or rainstorms. The important reasons causing slopes failure are human activity that sloping, building dams or embankments, digging ground engineering, sluicing in reservoirs, etc. Therefore, many researchers focus on slopes in many aspects. After many years engineering practising and theories researching, huge progress has accomplished in slope prevention's region. Anti-slide structure develops sharply especially.Anti-slide pile as one mean of anti-slide structure is widely used in order to improve stability of slope. But the designing and computing theory of anti-slide pile is not perfect. Traditional designing and computing theories build on some assumption which avoid comprehensively analyzing interaction between anti-slide pile and soil mass in some degree. For example foundation coefficient method simplifies complicated factors such as interaction between soil and pile as pure foundation coefficient through winkler assumption. There are still some plastic theories and limited theories. Some assume the pile as rigid body, others assume pile and soil achieved the limited balance. In one word, all these theories can't completely analyze the mechanism of pile and soil. Today's Finite element method analysis mainly focuses on analyzing anti-slide pile and initial station of slope, and seldom analyzes the slope's displacement, stress, strain and stability after stabilized by anti-slide piles.In this paper, the major technical questions are discussed of slope prevention engineering, Firstly, the interaction between pile and soil is demonstrated. Secondly optimal design is carried through in pile's every designing phase. Thirdly the theory of finite element method is demonstrated. Finally theories are applied in engineering example. The conclusions are as follows.1. The transfer mechanism has been analyzed for the landslide thrust between the pile and slope using the soil arching theory. In this theory land thrust is transferred by soil arching from high to low. When soil arching does not transfer landslide thrust to slope body, Anti-slide piles bear all landslide thrust. When partly landslide thrust transfer to slope body, anti-slide piles take on partly.2. When calculating the design thrust, resistance of slide mass in front of pile should be taken into account. The resistance force is assumed P1=ηP. So the design thrust is P/l-T|. In fact the thrust piles bearing is parallel to the slide surface So the true design thrust is P_d=Pcosα/l-η.3. There are different formulas calculating the pile spacing for different conditions. The site of piles is the place where the difference of thrust is minimum .This theory is applied in designing Zhiyangchang slope prevention.4. Finite element method of slope is demonstrated. Rock mass is considered as perfect elastoplastic materials. This kind material obeys Drucker-Prager yield criteria. Flow rule is G=f, Hardening rule is A=0. Finally, constitutive relation described by plastic increment theory is. Pile structure is elastic material. The stress increment can be computed via the elastic stress-strain relations. Constitutive relation is is elastic stress strainmatrix. Contact surface and slide surface simulate by Goodman elements. Constitutive relation is4. The ways of solving nonlinear elastic plastic problems in ANSYS is demonstrated .6. Analyzing by FEM software ANSYS. the effect of landslide prevention engineering is estimated. The result shows that if we do not carry out some prevention engineering, the displacement and stress of slope will be larger and more dangerous. The slope failure disaster maybe happen. But the displacement and stress is under-control after setting anti-slide pile. All These shows anti-slide piles have effected on landslide. And so on, the landslide prevention is successful.