Soil arching is a critical mechanism in understanding the soil-pile interaction of pile-reinforced soil slopes. Previous research primarily focuses on evaluating the arching behavior under static loading conditions, whereas the seismic response of soil arching under earthquake loading remains unclear. This paper aims to investigate the seismic arching behavior in pile-reinforced soil slopes through a series of reduced-scale shaking table tests. The soil deformation characteristics, distribution of dynamic earth pressures, and internal forces of piles were systematically analyzed to evaluate the geometry characteristics and load-transfer ability of soil arching with varying input peak ground acceleration (PGA), pile spacing, and relative density of soils. The results indicate that soil arching that grew in either a wider pile spacing or loose sand tended to fully develop under low input PGAs and exhibited a higher arching height. Following this, a practical model was proposed to predict the stable arching height. With increasing the input PGAs, the seismic arching behavior involved four stages, termed stable, transitional, meta-stable, and failure. The load-transfer ability and seismic response of piles under earthquake loading were dependent on the pile spacing and relative density of soils. A wider pile spacing gave rise to a greater load-transfer ability which was enhanced in the stable arching stage and then diminished in the subsequent stages, showing a different trend from closer pile spacings. Compared to medium dense sand, loose sand reduced the load-transfer ability, but it promoted the occurrence of stable arching and elevated the point of dynamic load application. Furthermore, in the arching failure stage, arching footholds played a crucial role in maintaining slope stability as their instability directly resulted in overall slope failure. These findings are of practical significance for the design and construction of soil slopes reinforced with piles.

来源平台：SOIL DYNAMICS AND EARTHQUAKE ENGINEERING