Long-Term Performance Assessment of Base Isolated Buildings through Field Testing (ERIES-PASFIT)

This project involves both numerical and experimental investigations into the performance of sliding bearings. Specifically, full-scale static and dynamic in-situ tests were carried out on a base-isolated building that have been in service for approximately 15 years. The results of these field tests aim to address significant research gaps related to the behavior and performance of base-isolated structures. Key areas of investigation include: the effects of aging and deterioration on isolators, dynamic interactions with both the substructure and superstructure, and the variability of mechanical properties among isolation devices, as well as the implications of such variability across the isolation plane.

The test specimen is one of the buildings constructed in the aftermath of the 2009 L’Aquila Earthquake. As part of the C.A.S.E. Project, around 150 base-isolated buildings were erected in the vicinity of L’Aquila (Italy) to provide safe housing for approximately 12,000 people left homeless by the disaster.

The specimen is a three-story building supported by a 21 by 45 meter, 500 mm-thick reinforced concrete slab. This slab rests on 32 isolation bearings mounted on top of hollow steel tube columns, forming a “column-top” isolation system. The total mass of such a building plus the concrete slab is approximately 1500 tons, excluding variable loads.

This project represents a unique initiative within ERIES. It features the first in-situ experimental quantification of the aged, collective behavior of seismically isolated buildings. The knowledge generated will help assess whether existing base-isolated structures perform as intended by Eurocode standards and identify any necessary design modifications to ensure target performance levels under real-world conditions.

The experimental campaign of the ERIES-PASFIT project was conducted using the EUCENTRE-IUSS mobile testing system, MOBILAB, specifically designed to bring on site the advanced laboratories seismic testing capabilities; a video of the test campaing can be found at this link: https://youtu.be/xQtgx_ZMlH0?si=zjRA7kEsWBKhI2UA.

ERIES is funded by the European Commission’s Horizon Europe programme. Coordinated by the Scuola Universitaria Superiore IUSS in Pavia, it has a budget of €11.6 million and spans four years, from 2022 to 2026. The project provides transnational access to cutting-edge research infrastructures in structural, seismic, wind, and geotechnical engineering. It aims to enhance resilience to natural hazards such as earthquakes and extreme wind events by promoting innovative, sustainable solutions to reduce economic losses and social disruption. Furthermore, ERIES supports the development of new technical standards and methodologies, advancing infrastructure safety and fostering frontier research through international collaboration.