Effect of Using Compressible Inclusion Around Footing on the Behavior of Short-Period Structures Under Seismic Loading

Abstract

This paper presents a study to investigate the seismic performance of short-period structures using compressible materials around foundations. Short-period structures are exposed to high seismic loads as a result of being located in the sensitive region of the acceleration response spectrum. A potential solution to this problem is to enclose the foundations of these structures with compressible materials such as expanded polystyrene foam in order to shift the periods of such structures from the sensitive region in the acceleration response spectrum to longer periods. A parametric study was carried out to examine the effect of using expanded polystyrene foam on the fundamental natural period of structures with isolated footings by analyzing single-degree-of-freedom systems. Results indicate that the use of expanded polystyrene foam has a significant effect on shifting the fundamental natural period of structures depending on the soil type. An increase in the period was up to 55%, compared to SDOF systems with a fixed-base.