Search results for " Pushover"

A new hybrid procedure for the definition of seismic vulnerability in Mediterranean cross-border urban areas

2016

Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologie…

Definition of Seismic Vulnerability Maps for Civil Protection Systems: The Case of Lampedusa Island

2016

The opportunity to locate and quantify the major criticalities associated to natural catastrophic events on a territory allows to plan adequate strategies and interventions by civil protection bodies involved in local and international emergencies. Seismic risk depends, most of all, on the vulnerability of buildings belonging to the urban areas. For this reason, the definition, by a deep analysis of the territory, of instruments identifying and locating vulnerability, largely favours the activities of institutions appointed to safeguard the safety of citizens. This paper proposes a procedure for the definition of vulnerability maps in terms of vulnerability indexes and critical peak ground …

Seismic Performance of Masonry Infilled RC Structures via N2 Pushover Assessment Procedures: Outcomes under Different Modeling Hypotheses of a Case S…

2016

The assessment of the capacity of RC masonry infilled RC structures constitutes nowadays a still debated issue. Pushover based procedures for the evaluation of seismic performance, such as N2 method, are largely used in practice and in force in several technical codes. The latter has proved to be reliable for a large number of structural typologies, however in the case of infilled frames, the choices made on the modelling strategy may radically modify the outcomes observable from the capacity curves and the consequent performance levels achievable. In the paper, the extent of different modelling choices on the results of the application of N2 procedure is investigated by the deep analysis o…

Influence Of Lateral Load Distributions On Pushover Analysis Effectiveness

2008

The effectiveness of two simple load distributions for pushover analysis recently proposed by the authors is investigated through a comparative study, involving static and dynamic analyses of seismic response of eccentrically braced frames. It is shown that in the upper floors only multimodal pushover procedures provide results close to the dynamic profile, while the proposed load patterns are always conservative in the lower floors. They over-estimate the seismic response less than the uniform distribution, representing a reliable alternative to the uniform or more sophisticated adaptive procedures proposed by seismic codes. © 2008 American Institute of Physics.

Influence of column shear failure on pushover based assessment of masonry infilled reinforced concrete framed structures: A case study

2017

Structural frames, constructed either of steel or reinforced concrete (RC), are often infilled with masonry panels. However, during the analysis of the structural frames, it has become common practice to disregard the existence of infills because of the complexity in modeling. This omission should not be allowed because the two contributions (of infills and of frames) complement each other in providing a so different structural system. The use of different modeling assumptions significantly affects the capacity as well as the inelastic demand and safety assessment. In specific, the adoption of equivalent diagonal pin-jointed struts leaves open the problem of the evaluation of the additional…

Il recupero parziale di opere in muratura di interesse storico in zona sismica

2011

Nonlinear Analysis of Reinforced Concrete Frames: Safety Evaluation and Retrofitting Techniques

The multiple slope discontinuity beam element for nonlinear analysis of RC framed structures

2018

The seismic nonlinear response of reinforced concrete structures permits to identify critical zones of an existing structure and to better plan its rehabilitation process. It is obtained by performing finite element analysis using numerical models classifiable into two categories: lumped plasticity models and distributed plasticity models. The present work is devoted to the implementation, in a finite element environment, of an elastoplastic Euler–Bernoulli beam element showing possible slope discontinuities at any position along the beam span, in the framework of a modified lumped plasticity. The differential equation of an Euler–Bernoulli beam element under static loads in presence of mul…

Tecniche di analisi statica non lineare multimodale per strutture intelaiate

2015

Viene presentata una panoramica delle più efficienti tecniche di analisi statica non lineare, evidenziando i progressi fatti nella formulazione di procedure con profili di carico adattivi multimodali, finalizzati alla valutazione della risposta di strutture a comportamento fortemente non lineare. Vengono poi presentate le diverse procedure che consentono di analizzare il comportamento di strutture irregolari in altezza o con grandi periodi di vibrare, nella quale la risposta è fortemente influenzata dai modi superiori. In quest’ambito viene evidenziato il ruolo della procedura Modal Pushover Analysis, che risulta fra le più efficienti nel riprodurre il comportamento di strutture fortemente …

Definizione di Mappe di Vulnerabilità Sismica per le Aree Mediterranee Transfrontaliere: Il caso di Lampedusa

2015

La possibilità di individuare e quantificare le principali criticità legate ad eventi catastrofici naturali su un territorio, consente di pianificare strategie e interventi adeguati da parte degli organismi di Protezione Civile coinvolti in emergenze locali e internazionali. Il rischio sismico dipende soprattutto dalla vulnerabilità degli edifici appartenenti alle aree urbane. La conoscenza degli scenari di rischio è dunque fondamentale per pianificare e gestire azioni di assistenza in caso di emergenza e non può prescindere dalla quantificazione e localizzazione della vulnerabilità sismica. Il presente studio propone una procedura per la definizione di mappe di vulnerabilità sismica in ter…