Study On Calculation And Design Method Of Pile-wall Composite Anti-sliding Structure

The length of the Three Gorges Reservoir Bank is more than 5300 kilometers.The area of landslide hazard covers 21 administrative counties,and the area of flooded houses is up to 3400 spuare meters,which constitute a threat to more than 4 millions personal safety and property security.Therefore,it is a complex and demanding task of the prevention and cure project of Three Gorges Reservoir Bank.For the large wading landslide,its underground water fluctuates frequently,so prestressed ground anchor cable anti-slide pile is forbidden to used.Otherwise,the steel is easily corroded and the structure will be destroyed.It is a suitable treatment technology to use cantilever anti-slide pile and retaining walls.According to the stress situation of cantilever anti-slide pile,the longer the cantilevered end,the bigger the moment of cantilevered end,which caused the sectional dimension and reinforcement of anti-slide pile exponentially increases,is not reasonable.According to the specifications,because of the reduce of structure safety,it is strictly prohibited when the height of retaining walls is more than 8m.In order to explore effective treatment methods of the large wading landslide in Three Gorges Reservoir Bank,the new pile-wall composite anti-sliding supporting structure is proposed.The new structure is composed by retaining wall,pile cap and anti-slide pile,which contains their advantages:the eccentricity e₀ between pile and wall,and the negative moment MW of pile top caused by retaining wall.To promote the application of the new structure,the paper mainly studies the theory about the calculation of internal force and structural design of the new structure.The main researches achieved are as follows:?1?By comparing with cantilever anti slide pile and prestressed ground anchor cable anti-slide pile,the paper introduced the characteristics of pile-wall composite anti-sliding structure and its applicability;?2?The paper proposed the mechanics model of the structure,and deduced calculation method of internal force.Also it launched a design method by combining the existing noemative;?3?Combined with practical engineering of Jingquan landslide,the paper calculeted internal force,and analysed the optimum eccentricity when the structure adopts certain size.?4?According to the ANSYS numerical simulation of the practical engineering of Jingquan landslide,the optimum eccentricity is 1.13 meters.The characteristics of the new structure is much in evidence by contrust to the numerical simulation of cantilever anti slide pile.Through comparative analysis,the result of theoretical calculation and numerical simulation is reasonable.