Rainfall-induced slope instability is a critical challenge in geotechnical engineering. This study investigates the reinforcement effect of anti-slide piles on slope stability under rainfall conditions using finite element numerical simulations, based on a slope reinforcement project in Youxi County, Fujian Province. The MIDAS GTS NX 2019(v1.2) software was employed to analyze the effects of anti-slide pile arrangements on slope safety factors, pore water pressure, displacement fields, and reinforcement effectiveness. The results showed that anti-slide piles significantly enhanced slope stability by mitigating the adverse effects of rainfall, such as an increased pore water pressure and reduced soil strength. The optimal stability was achieved when anti-slide piles were positioned in the middle sections of the slope, and the horizontal displacement in the x-direction was reduced from 74.49 mm (without reinforcement) to 7.42 mm, achieving a reduction of 90.0%, effectively reducing horizontal displacement and plastic strain zones. This study provides valuable insights into the interaction mechanisms between anti-slide piles and soil, offering practical guidance for slope reinforcement design and strategies to mitigate rainfall-induced slope failures.

In civil engineering projects, the practice of partial excavation or backfilling of slopes often results in landslide occurrences because of the redistribution of internal stress within the slope mass. This paper presents the findings from scaled-model tests conducted to investigate the reinforcement of high-fill embankment slopes using anti-slide piles. During the filling process, data were meticulously monitored using strain gauges affixed to the pile bodies and embedded earth pressure cells. The analysis focused on the mechanical behavior, including load–displacement relationships at the pile tops, bending moments, and earth pressures. This study was designed to investigate how anti-slide piles contribute to slope stabilization and to evaluate their load-bearing behavior throughout the backfilling process. Additionally, particle image velocimetry technology was used to capture the variation patterns of the soil surface displacement field, thereby revealing soil displacement deformation and the overall failure mechanism. By integrating mechanical responses with the analysis of the soil displacement field, a more profound understanding of the pile–soil interaction mechanism was attained. This experimental method provided a comprehensive depiction of the entire process, from the initial slope movement to its eventual deformation and failure. The research indicates that a reduction in pile spacing leads to a decrease in the maximum bending moment of the pile body, thereby enhancing slope reinforcement. For the same pile spacing, the pile located on the first-level slope platform shows the smallest horizontal displacement at its top after deformation. The soil on either side of the anti-slide pile disperses outward from the pile body, with the maximum displacement occurring directly beneath the pile tip.