Soil-structure interaction is the key to study the behavior of the structure under static or dynamic loading. The pile foundation is adopted to transfer the load from the structure to the soil when the structure is embedded in a weak soil stratum. Soil-pile system has a nonlinear behavior, thus, it is more complicated to understand. This study focuses on the numerical investigations of interaction soil�pile�structure system (ISPS) and interaction soil�pile system (ISP) under lateral loads. The nonlinear static analysis is carried out considering the lateral capacity of ISPS and ISP system under lateral loading using the pushover analysis, with a parametric study. The results show that in most cases, the lateral capacity of the fixed system is low compared to lateral capacity in ISPS system when increasing the axial load, pile diameter and length of the pile in all types of sand. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021.