Mitigation of surface impact loading effects on the underground structures with geofoam barrier: Centrifuge modeling

Studying the effect of dynamic loads on underground structures and applying mitigation strategies to reduce these effects are important for the safe design of these structures. In this paper, the effect of dynamic loading on an underground structure and the performance of geofoam as a barrier were investigated using centrifuge tests. Impact loading, created by blasting, was used as an example of dynamic loads. Two sets of centrifuge experiments were performed to study different mitigation systems. The first set of the experiments included two tests, one without a barrier and the other with a vertical geofoam barrier installed between the impact source and the underground structure. The second set of the experiments included the following three tests: a test with no barrier between the impact source and the underground structure; a test where a horizontal geofoam barrier existed near the source of the impact load; and another test where a horizontal geofoam barrier existed near the underground structure. The results of the tests confirmed the effectiveness of the geofoam barrier against dynamic loading effects and indicated that the barrier effect was more prominent when it was installed near the structure. This study also provided a better understanding about the effect of impact loading on underground structures and mitigation effects.