Numerical Analysis of Geotechnical Seismic Isolation Using Expanded Polystyrene: Application to the EuroProteas Prototype at the Euroseistest Site

M. P. A. Gatto; Lorella Montrasio; C. Amendola; Eleni Filoglou; Dimitris Pitilakis; Hing-Ho Tsang

Publication Title
Numerical Analysis of Geotechnical Seismic Isolation Using Expanded Polystyrene: Application to the EuroProteas Prototype at the Euroseistest Site

Abstract

This study investigates geotechnical seismic isolation through numerical simulations of soil-structure interaction, focusing on the dynamic response of the EuroProteas prototype structure at the Euroseistest field site. A 50 cm layer of Expanded Polystyrene (EPS) was introduced beneath the structure as a potential geotechnical seismic isolation solution, aiming to reduce seismic energy transmission from the ground to the superstructure. Finite element analyses were conducted using PLAXIS 2D, with the soil modeled via the Hardening Soil Small-Strain (HS small) constitutive law, based on parameters derived from in-situ and laboratory tests. The soil-structure interface was represented using a frictional contact model incorporating a calibrated virtual thickness parameter to accurately simulate interaction behavior.The numerical model was calibrated by matching amplification functions from simulated free vibration tests to those obtained experimentally. Dynamic simulations were then performed to assess surface accelerations at measurement points up to 6 meters from the structure, comparing the baseline configuration with the EPS-isolated case. Results indicate that the EPS layer significantly alters the amplification characteristics of the coupled system, effectively modifying its dynamic response and demonstrating the potential of lightweight geotechnical materials for seismic isolation. Nonetheless, further experimental validation under real seismic loading conditions is necessary to confirm these findings and refine the numerical model. This study highlights the potential of geotechnical seismic isolation techniques and underscores the role of advanced numerical modeling in the development of innovative and practical seismic protection strategies.

Authors
M. P. A. Gatto; Lorella Montrasio; C. Amendola; Eleni Filoglou; Dimitris Pitilakis; Hing-Ho Tsang

Published In

11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)

Theme

Special Session 7: Geotechnical seismic isolation based on sustainable geomaterials