For the past 30 years, applications of expanded polystyrene (EPS) geofoam have been proposed. Several studies have examined the behavior of geofoam and produced beneficial results in the evolution of its application. One of application ofexpanded polystyrene can be used laid under the grade beam or slab. Meanwhile some of existing structure were suported by shallow foundation. Thus when EPS applied beneath shallow foundation to be alternative design, EPS supposed reduce theseismic response of structure. The purpose of this study is to investigate the seismic response of structure numerically due to application of EPS applied beneath the shallow foundation. In this study, the D7S2 finite element program was adopted toinvestigate the seismic response of structure due to apllication of EPS applied beneath the shallow foundation subjected to the earthquake motion. Verification and validation of the program was conducted by comparing the results to the shaking tabletest results. A series of parametric study is conducted including the interface element and the variations of size of EPS. The use of EPS underneath shallow foundation do not show the correlation with the seismic response of structure if there is no interface element constructed. Variation of EPS size used were contributed to the acceleration and displacement of structure with shallow foundation. As the larger size of EPS applied, the larger reduction of seismic responses will be obtained
