The explosive incidents to damage civilian infrastructures have been increasing in recent years. To protect people in/near facilities, the blast mitigation techniques for structures should be taken so as to result in the least damage. One of the measures is underground facilities with an explosion mitigation layer. The mitigation layer can provide additional explosive protective ability provided an expanded polystyrene (EPS) material is incorporated into the mitigation layer. In this study, to investigate shock absorbing effects by EPS material in the mitigation layer, explosion tests were conducted and ground shock pressure at the bottom of the mitigation layer was measured. It was observed that EPS material had high absorbing effects if brittle breaking of EPS material was prevented.
