Abstract: Anti-slide pile is widely used in landslide improvement in the Three Gorges Reservoir area. How about the effectiveness of the anti-slide piles construction and if it can ensure the landslide stability under the long period reservoir level fluctuation, which is one of the important subjects to be studied urgently. Taking Baishuigou landslide, which is the sub-landslide of Tianjiaping paleo-landslide located in the new Badong County, as a example, based on the engineering geological investigation results and anti-slide pile design data, the 2D finile element model was developed and the rational calculation parameters of the rock and soil and pile were chosen. According to the simulation scheme, with ANSYS software, with pile and without pile, the landslide stability under water level fluctuation, considering gravity only and gravity and strom, was simulated and analyzed separately. Based on them, we analyzed the effects of nti-slide pile under water level fluctuation and storm. The results show that: ① the deformation and failure mechanism of Baishuigou landslide is a pull-type. The landslide stability under storm and water level drawdown from 175m to 145m decreases; during the period water level fluctuation, the landslide stability gradually decrease further to failure. ② the piles, designed under water level drawdown considering the storm, is effective under storm and water level drawdown form 175m to 145m; ③ after a long term period water leverl fluctuation, the deformation has apparently gradually further incrtease; the landslide stability decrease further. Even though the anti-slide pile has anti-slide effectiveness, the anti-slide effectiveness is gradually decrease. Hence, we should consider the effect of the period water level fluctuation when we design antl-slide pile.

Key words: anti-slide pile, water level period fluctuation, effectiveness of anti-slide, finite element method