Dynamic Testing of a Seismically Isolated Deep Foundation: Insights from the ERIES-GISIS Project

Publication Title
Dynamic Testing of a Seismically Isolated Deep Foundation: Insights from the ERIES-GISIS Project

Abstract

The ERIES-GISIS (Geotechnical Innovative Seismic Isolation System) project, aligned with the goals of the ERIES initiative (Engineering Research Infrastructures for European Synergies), aims to test and validate an innovative seismic base isolation system designed to mitigate inertial forces transmitted to superstructures during earthquakes. The system is particularly appealing for the foundation retrofitting of existing buildings, especially masonry ones with historical and cultural significance. A key component of the study is the use of the EuroProteas full-scale model to simulate the dynamic response of a structure resting on a seismically isolated foundation. The experimental research investigates the increase in its fundamental natural period, the dynamic behaviour of the entire system, and the effects of soil-structure interaction. Building on extensive expertise in earthquake engineering and detailed knowledge of the existing full-scale model's dynamic behaviour, the study introduces a new micropiles foundation system integrating the isolation devices. This system involves a newly cast-in-place reinforced concrete foundation slab, installed directly above a set of isolation micropiles embedded in the soil. The resulting configuration features a superstructure supported by a deep seismically isolated foundation. A comprehensive campaign of forced-vibration tests has been conducted on the upgraded structural prototype structure, covering a wide range of input excitation amplitude and frequencies. The results aim to provide valuable insights into the effectiveness of the GISIS concept in enhancing seismic performance, with potential implications for the protection and preservation of vulnerable historical heritage.

Authors
Gianluca Fasano; G. Astuto; Emilio Bilotta; Alessandro Flora; Eleni Filoglou; Georgia Kroupi; Anastasios Anastasiadis; Dimitris Pitilakis

Published In

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

Theme

Special Session 7: Geotechnical seismic isolation based on sustainable geomaterials