Centrifuge modeling of seismic response and failure mode of a slope reinforced by a pile-anchor structure

Pile-anchor structures are now widely used in major slope reinforcement projects, but research on the seismic response of slopes reinforced by these structures has been very limited. This paper presents the results of a series of 50g dynamic centrifuge tests that reproduce the seismic response of a slope reinforced by a pile-anchor structure exposed to an earthquake-induced stress field. A silica gel model of a slope is used to conduct multiple tests. Long-period wave amplitude amplification and frequency filtering are observed after spectral analysis. Pile bending moments and anchor tensions were recorded before the earthquake, at the moment of peak ground acceleration, and after the earthquake and the data show that the pile is the main load-bearing structure. The anchor aids in keeping the pile from tilting outward to improve the durability of the pile. Pile-anchor structure failure is caused by anchor relaxation, pile bending, and slope displacement after the passage of multiple seismic waves. A suggestion for pile-anchor structure design is provided. This paper provides a useful reference for future research on the interactions between support structures and a slope during and after earthquakes. The conclusions provided by these tests lay the foundation for designing pile-anchor reinforcement structures for better dynamic performance.