The main focus of this paper is to present a multi-interaction model under a simplified form for calculating load transfer to piles and geosynthetic strain of piled embankments. The multi-interaction model is established by considering the integrated load transfer mechanisms and all the interactions between the elements of a geosynthetic-reinforced and pile-supported embankment, including fill soils, geosynthetic, platform, subsoil and pile. The proposed method is based on the combination of the tensioned membrane theory for geosynthetics, soil arching theory for fill soils, friction interaction model and, subsoil support. Thereby it allows providing a suitable design approach that enables a realistic and suitable approximation in designing soil–geosynthetic systems. The proposed method can be applied to both cohesive and non-cohesive fill soils. Using this method, the influence of the subsoil consolidation degree, subsoil ultimate bearing capacity, fill shear strength and platform, are investigated considering the behaviour and deformation of piled embankments. The result of the proposed method is compared to field measurements and to five other design standards to study its validity. The results showed a good agreement between the proposed method with measured data and are better than other design methods as well as two international design standards EBGEO and BS8006.