Abstract: To investigate the effects subsoil compressibility in geosynthetic-reinforced piled-supported embankments on load transfer under cyclic loading,several self-moving trapdoor tests were conducted.In the trapdoor tests,the trapdoor was supported by springs with different stiffness,which was used to simulate the subsoil with different compressibility,while the stationary portions on the both sides of the trapdoor were equivalent to piles.Quartz sand and geogrids were used as embankment fill and reinforcement material respectively.The results show that the development of soil arching and load transfer in the embankment fill under cyclic loading could be divided into three stages,namely initial stage,maximum stage,and degradation stage.Subsoil with lower compressibility limited the mobilization of soil arching and induced less deflection of the reinforcementshowing tensioned membrane effect.However, it caused embankment fill to have a higher load-carrying capacity of cyclic loading.In addition,an estimating method of additional vertical stress on the subsoil (trapdoor) induced by cyclic loading was proposed to reasonably assess the load transfer in geosynthetic-reinforced piled-supported embankments,which considered the effect of cyclic loading and subsoil compressibility based on the existing theoretical methods.Two types of calculated values of additional vertical stress on the trapdoor induced by cyclic loading could serve as the upper and low limits of measured values in the trapdoor tests respectively,calculated based on the wedge-arch model proposed by Rogbeck et al.and the concentric arches model proposed by van Eekelen et al.respectively.