Descripción del Sendero 2: Señalización y rotulación del Sendero

RESEARCH GROUP: Nicola Buratti, Giada Gasparini, Marco Savoia, Stefano Silvestri, Tomaso Trombetti KEYWORDS: earthquake engineering, accelerograms, intensity measures, nonlinear dynamic analysis, seis- mic hazard

In the framework of performance based earth- quake engineering, the assessment of the seismic structural demands is extremely important. This latter, is usually defined through a sequence of nonlinear dynamic analyses that require to define some sets of accelerograms as input. The choice of the accelerograms is crucial for the correct pre- diction of the structural response. The research carried out covered different aspects of this issue. The research group developed a new probabilistic seismic hazard analysis (PSHA) procedure that leads to the definition of the probability function (PDF and CDF) of the various intensities of the ground-motion. Using this results the group de- veloped a new vector ground-motion intensity measure based on the combination of PGA and PGV. Finally the research group studied the fea- tures (in terms of spectral acceleration) that a set of accelerograms must present in order to be as- sociated to a given probability of occurrence, and hence proposed a new procedure for defining sets of design ground motions.

The research group also developed a procedure for simulating non-stationary stochastic accelero- grams, using ground-motion prediction equations to obtain realistic estimates of some important ground motion intensity measures: duration, Arias intensity, and frequency content. The so generat- ed accelerograms were used as input for nonlinear dynamic analyses of various RC structures and gave results that compared very well with those obtained from recorded accelerograms.

Finally, as a results of a collaboration with Impe- rial College, London, we developed a new crite- rion to select and scale recorded accelerograms starting from the definition of a scenario in terms of magnitude and source-to-site distance. The procedure is based on the definition of a target response spectra, using the data provided by spec- tral-acceleration attenuation relationships. This method has given good results both in terms of estimates of the mean structural response and in

MAIN PUBLICATIONS

Buratti N. (2012) A comparison of the perfor- mances of various ground–motion intensity measures. 15th World Conference on Earthquake Engineering. Lisbon, 24-28 September.

Ligabue V., Buratti N. (2012) Analysis of code- based ground-motion selection procedures in terms of inelastic interstorey drift demands. 15th World Conference on Earthquake Engineer- ing. Lisbon, 24-28 September.

Buratti N., Stafford P.J., Bommer J.J. (2011) Earthquake accelerogram selection and scaling procedures for estimating the distribution of structural response. Journal of Structural engi- neering 137, 345-157.

Buratti N., Savoia M. (2010). Artificial Nonsta- tionary Accelerograms with Natural Variability. Proceedings of the Fourteenth European Confer- ence on Earthquake Engineering. Ohrid, Repub- lic of Macedonia. 30 Agosto - 3 September. Buratti N., Savoia M. (2010). Non-stationary Artificial Accelerograms for Nonlinear Analy- sis of R.C. Frame Structures. Proceedings of the Fourteenth European Conference on Earthquake Engineering. Ohrid, Republic of Macedonia. 30 Agosto - 3 September.

Buratti N. (2009). Generation of artificial non- stationary accelerograms with natural variabili- ty. XIII Convegno ANIDIS 2009- L’Ingegneria Sismica in Italia. Bologna. 28 June-2 July. Buratti N.,Savoia M. (2009). Using non-sta- tionary artificial accelerograms for estimating maximum drift demands on R.C. frame struc- tures. XIII Convegno ANIDIS 2009 - L’Ingeg- neria Sismica in Italia. Bologna. 28 June-2 July. Trombetti T., Ceccoli C., Silvestri S., Gasparini G. (2003). Probability Density Function of the Peak Ground Acceleration due to the Seismic Action. Proceedings of the 9th International Con- ference on Applications of Statistics and Probabil- ity in Civil Engineering - ICASP 9. San Francis- co. California, 6-9 July.

Trombetti T., Gasparini G., Silvestri S. (2004) Statistical characterisation of the seismic action (PGA and PGV) for Performance Based Seis- mic Design, Proceedings of the 13th World Con- ference on Earthquake Engineering. Vancouver, B.C., Canada, 1-6 August.

Trombetti T., Silvestri S., Gasparini G., Ma- lavolta D. (2006), “Identification of efficient groups of design earthquake inputs”, Proceedings of the First European Conference on Earthquake Engineering and Seismology. Geneva, Switzer- land, 3-8 September.

Trombetti T., Silvestri S., Malavolta D., Gaspar- ini G. (2007). A methodology for determi- nation of efficient earthquake bins for Perfor- mance Based Seismic Design. Proceedings of the “Tenth International Conference on Applications of Statistics and Probability in Civil Engineering - ICASP10. Tokyo, Japan, 31 July – 3 August. Trombetti T., Silvestri S., Gasparini G., Righi M., Ceccoli C. (2008). Correlations between the displacement response spectra and the pa- rameters characterising the magnitude of the ground motion. Proceedings of the 14th World Conference on Earthquake Engineering. Beijing, China, 12-17 October.

Silvestri S., Trombetti T., Gasparini G. (2009) A Procedure For Probabilistic Seismic Hazard Analysis Which Allows To Account For Pois- son Or Non-Poissonian Models. Proceedings of 10th International Conference on Structur- al Safety and Reliability. Osaka, Japan, 13-17 September.

Trombetti T., Silvestri S., Gasparini G. (2009). The Role Of Epsilon For The Identification Of Groups Of Earthquake Inputs Of Given Haz- ard. Proceedings of 10th International Conference on Structural Safety and Reliability. Osaka, Ja- pan, 13-17 September.

CONTACTS

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Fig. 1. IDA curves calibrated for a given seismic intensity measure.

Fig. 2. Fragility curves obtained from response surface models.

Fig. 3. Fragility curves for cylindrical tanks.