Diaphragm CApacity of Beam and block Existing floors (ERIES-DICABE)

The ERIES-DICABE (DIaphragm CApacity of Beam and block Existing floors) project is an experimental programme focused on the seismic in-plane behaviour of existing beam-and-clay block floor diaphragms representative of construction techniques widely adopted in Mediterranean countries prior to the introduction of modern seismic design provisions. A full-scale quasi-static in-plane test on a 9.3 m × 3.9 m floor specimen was carried out at the laboratories of EUCENTRE in Pavia, Italy, while material mechanical characterisation was performed at the Material and Structural Testing Laboratory of the University of Bergamo. The tested system consisted of a traditional beam-and-block configuration with reinforced concrete joists and hollow clay infill units. The study targets the assessment of in-plane deformation capacity, stiffness, and local failure mechanisms under seismic loading conditions, with particular emphasis on realistic geometric and mechanical behaviour. In line with common construction practice in older buildings and to reproduce a critical configuration for diaphragm action, the specimen was built without a concrete topping slab.

The main objectives of the project are:

(i) assessment of the in-plane capacity of beam-and-clay block floors without concrete topping;

(ii) definition of performance levels associated with different damage states in existing diaphragms;

(iii) calibration and improvement of simplified analytical capacity models;

(iv) establishment of a benchmark for advanced finite element modelling approaches;

(v) evaluation of the elastic stiffness of existing floor systems;

(vi) development of demand models and seismic fragility relationships for these floor typologies.

These objectives have been addressed through a combination of material characterisation tests and full-scale quasi-static in-plane tests on the floor system. In addition, complementary numerical and analytical models were developed to support the interpretation of the experimental results and to enhance the understanding of the observed structural behaviour.This experimental programme was a collaborative effort involving the University of Leeds (Leeds, United Kingdom), Università degli Studi di Bergamo (Bergamo, Italy), University of Bristol (Bristol, United Kingdom), Università degli Studi “G. d’Annunzio” Chieti-Pescara (Chieti, Italy), Universidad Nacional Autónoma de México (Ciudad de México, Mexico), ASDEA (Pescara, Italy), and EUCENTRE Foundation (Pavia, Italy).

The experimental campaign of the ERIES-DICABE project was carried out at the EUCENTRE-IUSS Research infrastructure, within the framework of ERIES project (Engineering Research Infrastructures for European Synergies). ERIES is funded by the European Commission's Horizon Europe program, it is coordinated by the Scuola Universitaria Superiore IUSS in Pavia, has a budget of €11.6 million and has a four-year duration, from 2022 to 2026. ERIES aims to provide transnational access to advanced research infrastructures in structural, seismic, wind, and geotechnical engineering. The project seeks to enhance resilience against natural hazards such as earthquakes and extreme winds by fostering innovative and sustainable solutions to mitigate economic losses and social disruptions. Additionally, it develops new technical standards and methodologies to improve infrastructure safety and supports frontier research through international collaboration.