Abstract: Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries, especially in China and Japan. In contrast to strut, pile-anchor retaining structure has several typical features and advantages. It doesn’t occupy the internal space of the foundation pit and the project cost is much lower. With the technology of prestress, engineers can control the deformation of the retaining wall actively which is impossible in inner supporting structures. Accurate prediction of the lateral displacements of the retaining structure is very important in the design stage. An analytical evaluation model and several calculation assumptions of lateral displacements of pile-anchor retaining structure are set up according to measured data of several foundation pits from different cities in China. The deformation of the retaining wall under each external force is calculated. The expression of lateral displacement versus depth is solved by means of quasi-elastic summation; and the parameters are obtained from the stiffness equation of the anchors. The analytical evaluation of the lateral deformation curve is then completed. The simplified method is suitable for braced excavation with small displacement at the bottom of the retaining wall. The applicability of the proposed method is validated by practical engineering.

Key words: excavation, pile-anchor retaining structure, lateral displacement, simplified algorithm