The composite retaining structure with pile

anchor and reinforced earth plays more and more important role in the treatment of large and complex landslides.In this paper

considering the airport landslide in a high fill mountain area

a model test is carried out to study the rainfall effect on the composite retaining structures with piles

anchors and reinforced soil

which is used to enhance the stability of the slope.The test results show that:（1）There are three stages for the development of pile top displacement with the change of water injection time:the initial gradual increase stage

development stage

secondary gradual increase stage.The top displacement variation of the rear cantilever pile is larger than that of the front embedded pile.Therefore

when multi-row anchor piles are used to reinforce a slope and the rear row piles are cantilevered

it is recommended to install rear piles with larger cross-sectional areas than the front piles

and the spacing between anchor cables should be smaller

so as to reduce the pile top displacement and enhance the slope stability.（2）The displacements of the fill slope change with the water injection time

the displacement of the top slope level is the largest

and displacement decreases with the increase of slope levels.Therefore

the reinforcement of the multistage slope can appropriately increase the number of the anchor lattice beams.（3）It shows that the back edge of the filling slope has larger settlements that the front edge.（4）The deformation of the reinforced soil is consistent with that of the slope mass

indicating that the reinforced soil can enhance the integrity of the filling slope.（5）All the monitoring curves tend to be flat eventually

indicating the excellent performance of the pile-anchor-reinforced soil composite structure system.