Study on Anchorage Length of Anti-slide Pile in Landslide Prevention in the Three Gorges Reservoir AreaZHOU Chun-mei,YIN Kun-long(School of Engineering,China University of Geosciences,Wuhan 430074,China)The technique anti-piles was an effective measure in landslide control works,which nowadays had wide application in the fields of geo-hazard control in the reservoir area of Three Gorges Project in China.Usually,the pile's anchorage length was 1/2～1/3 of the pile's length.This paper analyzed existent problems on anti-slide pile's anchorage length as the experience.By elastic foundation coefficient method,this paper calculated lateral stress that elastic pile acts on surrounding rock soil.Rock's transverseallowable bearing value is classified and confirmed according to its engineering geological characters.When the sliding surface was gradient not even,the minimum anchorage length is given by checking the safety against sliding of adverse structural unit in the rock.A case of project showed that anchorage length of anti-slide pile was confirmed synthetically by some factors,such as pile's different structural form,strength of stabilized stratum,landslide thrust,pile's bending rigidity,section and space between piles,and slice resist force before piles.landslide stabiliting;anchorage length;transverse allowable bearing value; foundation coefficient;cable-anchor pile