Indicadores de Criterios de Sostenibilidad en la RGP

RESEARCH GROUP: Giada Gasparini, Stefano Silvestri, Tomaso Trombetti KEYWORDS: shaking table, dynamic tests, modelling, design

Shaking tables represent the main test tool for the evaluation of the dynamic and seismic be- haviour of structures. The first tables were real- ised at the end of the 60’s and at the beginning of the 70’s and were often used for tests of scale models with linear elastic behaviour. Since the first 90’s, they became the object of an extensive research activity for the development of a next generation of such tools capable of offering new and better possibilities. This next generation of shaking tables (Rice University at Houston, University of Firenze, LHPOST shaking table at San Diego, Eucentre in Pavia, …) is character- ised by:

(a) high accuracy in the displacements repro- duction,

(b) large dimensions (in order to allow dynamic tests upon small-scale structures, to better cap- ture the post-yielding behaviour),

(c) capability of well reproducing near-fault seismic input (characterised by very large values of peak ground velocity and displacements). The scientific activity mainly lies in the develop- ment of an analytical/numerical model of the dynamic functioning of the shaking table capa- ble of effectively capturing its actual behaviour (creation of a virtual model of the table). This model has revealed to be very useful for: (a) the design project of new shaking tables, (b) for their adjustments, and (c) for the study devoted to the minimisation of the interactions between the table itself and the testes structures.

Recently (2010-2013), the research group planned, designed and directed two experimen- tal shaking-table test campaigns:

1. Tests on a full-scale 3-storey building struc- ture realized with sandwich r.c. panels, at the EUCENTRE Lab in Pavia.

2. Tests on scaled models of flat-bottom si- los containing grain –like materials, at the EQUALS Lab in Bristol (UK).

Total publications: 20.

MAIN PUBLICATIONS

T. Trombetti, S. Silvestri, G. Gasparini, I. Ricci, S. Ivorra, D. Foti (2013). Preliminary results of a shaking table tests on a 3-story building realized with cast in place sandwich squat concrete walls, ISEC-7, Honolulu, June 18 –23, 2013.

D. Foti, S. Ivorra, T. Trombetti, S. Silvestri, G. Gasparini, L. Di Chiacchio, Final Report – AS- ESEGRAM project, “Assessment of the SEis- mic behaviour of flat-bottom Silos containing GRAin-like Materials”, February 2013.

T. Trombetti, S. Silvestri, G. Gasparini, I. Ricci, S. Ivorra, D. Foti (2011). Progettazione di una prova su tavola vibrante di un edificio a tre pia- ni in scala reale costituito da pareti sandwich in c.a. gettato in opera, XIV Convegno Nazionale “L’Ingegneria Sismica in Italia” ANIDIS 2011, Bari, 19 - 22 Settembre 2011.

Ozcelik O., Luco E., Conte J.P., Trombetti T. and Restrepo J. (2008). Experimental characteriza- tion, modeling and identification of the NEES- UCSD shake table mechanical system. EARTH. ENG. & STR. DYN. vol. 37-2, 243-264. Conte J.P. and Trombetti T. (2000). Dynam- ic modeling of a uni-axial shaking table system. Earthquake Engineering & Structural Dynamics 29, 1375-1404.

Trombetti T. and Conte J.P. (2002). Shaking Ta- ble Dynamics: results form a test-analysis com- parison study. Journal of Earthquake Engineering 6(4), 513–551.

Trombetti T., Conte J.P. and Durrani A.J. (1998). Actuator-foundation-specimen interaction in a small shaking table. Proceedings of the 12th ASCE Engineering Mechanics Specialty Conference, San Diego, California, 770-773.

Trombetti T., Barrasso P., Crewe A., De Stefano M., Gasparini G., Nudo R., Rutenberg A., Silves- tri S. and Taylor C. (2004). Shaking table testing of symmetric and asymmetric three-storey steel frame structures. Atti del 13th World Conference on Earthquake Engineering - 13WCEE, Vancou- ver, B.C., Canada, August 1-6, Paper No. 1248. Trombetti T., Conte J.P. and Durrani A.J. (1999).

Correlation Studies between Analytical and Ex- perimental Dynamic Behavior of the Rice Uni- versity Shaking Table. Structural Research at Rice Report N°. 49. Rice University, Houston, Texas. Trombetti T., Conte J.P. and Durrani A.J. (1999). Analytical Modeling of a Shaking Table System. Structural Research at Rice Report N°. 48. Rice University, Houston, Texas.

Aprile A., Benedetti A. and Trombetti T. (1994). On Non Linear Dynamic Analysis in the Fre- quency Domain. Earthquake Engineering & Structural Dynamics 23, 363–388.

RESEARCH PROJECTS

Progettazione e realizzazione di una tavola vi- brante (2000-2001): Università di California a Los Angeles.

Sperimentazione dinamica su tavola vibrante (2000-2001): Bristol (UK).

Shake down test for a large shaking table facility (responsabile delle prove di caratterizzazione e messa a punto per una tavola vibrante di ampie dimensioni) 2004: Università di California San Diego (finanz. NISEE – prog. Marco Polo). Progetto Giovani Ricercatori: Analisi e controllo del funzionamento dinamico delle tavole vibran- ti”, Univ. di Bologna 2000/2001, T. Trombetti. Prove di messa a punto ed accettazione di tavo- la vibrante monoassiale a movimento idraulico (2005): Eucentre – Pavia.

Progetto di ricerca SERIES (2010-2011): “Seis- mic behavior of structural systems composed of cast in situ concrete walls”, EUCENTRE TREES Lab facility (Pavia, Italy), Lead User: Prof. Salva- dor Ivorra Chorro, University of Alicante, Resp. Unità di Bologna: Prof. Tomaso Trombetti. Progetto di ricerca SERIES (2010-2011): “As- sessment of the seismic behaviour of flat-bottom silos containing grain-like materials”, EQUALS Laboratories (Bristol, UK), Lead User: Prof. Dora Foti, Politecnico di Bari, Resp. Unità di Bo- logna: Prof. Tomaso Trombetti.

CONTACTS

Fig. 1. Identification of natural frequencies for a building.

Fig. 2. Test of environmental vibration for a fly- over.

Fig. 3. Forced vibration test on a pedestrian bridge.