Model tests and numerical analysis of slopes reinforced by short anti-sliding piles

As an active protective structure for landslide prevention, the short anti-sliding piles have been gradually developed and applied in the engineering field. However, this kind of structure is only suitable for landslides where the strength of the sliding mass is obviously greater than that of the sliding surface, and there is also no shallow landslides. The rainfall-induced landslides are generally shallow ones, which limits the application of short anti-sliding piles. For the slopes improved by anti-sliding piles, three kinds of groups model tests are conducted under natural conditions. A single row of short anti-sliding piles are installed with different pile lengths (0, 18 and 28 cm) for reinforcing the non-cohesive soil slope. The PFC^2D particle flow software is used to simulate deformation of the soil slope. By analyzing the displacement of sliding body and the variation of the sliding surface, the reinforcement mechanism of the short anti-sliding piles with different lengths in the soil slope is studied. The results calculated by the discrete element numerical analysis method are close to those of the model tests. The results show that the short anti-sliding piles can effectively strengthen the soil slopes. With the increase of the length of short anti-sliding piles, the scope of the reinforced soil gradually increases, and the slip surface gradually rises along the vertical slope direction. However when the length reaches a certain value, the rising rate of the slip surface begins to decrease. The slope reinforced by the short anti-sliding piles still has the tendency of shallow sliding. If the pile length is too short, the slope soil will easily slide over the top of the pile. For the possible slope failure of overtopping and shallow sliding, it is suggested that the short anti-sliding piles should be used together with the retaining wall at the slope toe.