Giuliano Augusti

Seismic vulnerability of monumental buildings

Abstract Monumental buildings are by definition unique buildings that cannot be reduced to any standard structural scheme: this makes it difficult to evaluate their seismic reliability, because—in addition to the many uncertainties that are common to all existing (and in particular “old”) buildings—no statistics on the behaviour of similar buildings can be available. To overcome this problem, the macroelement approach has been proposed a few years ago and since then repeatedly used to analyse and compare the seismic response of monumental buildings: the structural organism is considered as the assemblage of few components (e.g. the whole facade of a church) whose behaviour is typical of the behaviour of analogous macroelements in other buildings, and whose possible collapse mechanisms can be identified. In these studies, quasi-static loads have been used, as indeed common in many analyses of the seismic behaviour of masonry structures. This paper accepts these simplifying assumptions, and shows how—assuming appropriate probabilistic properties of the relevant quantities and a “logical diagram” describing the relation between collapse of macroelements and whole building—the probability of collapse and damage of each macroelement and of the whole building under given horizontal loads can be assessed. The procedure is formulated in detail with special reference to churches, and illustrated on two example cases. The same procedure can be used as the basis of a statistical extrapolation aimed at evaluating the probability distributions of collapse and damage among monumental buildings that are similar with regard to both the macroelement typologies and the logical diagram.

MODELLING THE DYNAMICS OF LARGE BLOCK STRUCTURES

This paper summarizes the main critical points that arise when the problem of modelling the dynamics of block structures is tackled. In the first sections, a rigorous formulation of dynamics and impact problem is presented for a single rigid block freely supported on rigid ground, in order to illustrate the basic difficulties concerning the modelling of more complicated structures. Then, a critical review is presented on the numerous researches performed on this subject and the results achieved, and the problems still open, are put in evidence.

Optimal planning of retrofitting interventions on bridges in a highway network

The aim of the co-ordinated research effort initiated by the Authors consists in developing life-cycle reliability-based methodologies for the management and retrofitting of deteriorating structures and lifelines. As a first step, network systems with vulnerable nodes are considered. The object of this paper is the optimal planning of retrofitting interventions on bridges included in a highway network, taking into account their deterioration and the limitation of available economic resources. The procedure is illustrated with reference to a 10-node network. It is assumed that the resources available for retrofitting are not sufficient to guarantee the required structural reliability for all bridges throughout the design service life: thence the set of retrofitting interventions is sought that maximizes the network reliability (defined as the probability of maintaining connectivity) under a constraint on the total expenditure. The allocation is performed by means of a dynamic programming procedure.

Accreditation of engineering programmes: European perspectives and challenges in a global context

The EUR-ACE Socrates-Tempus project (September 2004/March 2006) proposed a decentralized European system for accreditation of engineering programmes in the “Bologna process” area (European Higher Education Area) at the First and Second Cycle (FC and SC) level (but including “Integrated Programmes”, i.e. programmes leading directly to a SC degree). In this system, “national” engineering accreditation agencies would continue to award their accreditation certificates and give them an added European value by the EUR-ACE quality label, recognized by all participating agencies: this rather novel way of international accreditation will create a consistent accreditation system of engineering education at the continental scale. A non-profit Association (ENAEE) has been established for support and supervision of the EUR-ACE system, and is now working, thanks also to two new EC-supported projects, in order to make the EUR-ACE proposals operational and award the EUR-ACE labels. The background, present status and perspectives of the EUR-ACE system is presented in detail in this paper.

Tuning engineering education into the European higher education orchestra

The ‘Bologna process’ is promoting fundamental changes throughout European higher education. Education ministers appear determined to reach, by 2010, a significant convergence of the national educational systems. This implies the necessity of adapting curricula in terms of structures, contents, learning attributes, learning tools and assessment methods. The EC ‘Tuning’ project was set up in order to investigate the feasibility of this process on the basis of ‘available experience and recent developments in several of the Member states… particularly from previous and on-going European co-operation in the context of the Socrates programme’. The Tuning project, initially aimed at five areas only (mathematics, geology, business, history, educational sciences), was later extended to other areas, including engineering: synergy groups were formed for this purpose. This paper summarizes the final report of the Engineering Synergy Group, which examined the ‘tuning’ of engineering education (EE) into European higher education, taking advantage of the work of previous and current thematic networks, such as H3E, EUCEET and E4. A set of recommendations is presented in the final section of the paper.

Transnational recognition and accreditation of engineering educational programmes in Europe: perspectives in a global framework

In a previous paper the author described the present situation and recent advances regarding accreditation of engineering programmes in Europe. This paper contains an attempt at examining perspectives from a global viewpoint. While the variety of educational approaches within European higher education is to be considered a great asset of the European cultural background, the ‘Bologna Process’ is working to build up the ‘European Higher Education Area’ (EHEA) and ‘a system of easily readable and comparable degrees’ in the context of making Europe ‘the most competitive and dynamic knowledge-based economy in the world’. In this framework a pan-European system of accreditation of engineering programmes and qualifications will be essential in order for European engineers to be competitive on a global scale. While the merely ‘professional’ aspects of recognition are covered by the European Directive 2005/36/EC ‘on the recognition of professional qualifications’ (which replaces all previous Directives on the subject, including the 1989 General Directive 89/48/EEC), little progress has been made towards trans-European accreditation of educational programmes as the entry route to a profession. This is particularly damaging in highly internationalized professions, like engineering. Several initiatives have been put forward in recent years to remedy this situation: in particular, this paper will illustrate the current EUR-ACE (EURopean ACredited Engineer) project, which is working towards the establishment of a European system for accreditation of engineering educational programmes based on a network of spontaneous agreements between national and regional bodies and associations concerned.

Optimal allocation of resources in reduction of the seismic risk of highway networks

Abstract The optimization of preventive upgrading interventions on the bridges of a highway network in an earthquake prone area is tackled. The bridges are assumed to be the vulnerable elements of the network, whose main purpose is to connect two sites. If the probability of collapse of each bridge under an earthquake of given intensity is known, the topology of the network allows us to calculate its reliability, i.e., the probability of maintaining the connection between the source node and the destination node. To increase the reliability, preventive upgrading interventions must be designed: the main purpose of this study is to present a procedure, based on dynamic programming, which is able to distribute the interventions among the bridges so that, for a given total amount of employed resources, the increase in reliability is maximized. The applicability of the procedure is demonstrated by some complete numerical examples. Alternative choices of the objective function and other further developments are also discussed.

Is Aeolian risk as significant as other environmental risks

Abstract Wind is the origin of many risks. These are identified and defined in 1 Introduction , 2 What is Aeolian risk? of this paper. The effects of climate changes are discussed in Section 3 , while structural vulnerability to wind actions is the object of Section 4 . In addition to the heavy damages that can be caused by windstorms, the wind climate affects significantly the quality of life through phenomena like wind-borne pollution that are addressed in Section 5 . Section 6 addresses specifically experimental research on wind effects. The final sections discuss some current and forthcoming research on assessment and reduction of wind risks.

Trans-national recognition and accreditation of engineering educational programmes in Europe: recent developments

The “Bologna Process”, started in 1998/99 with the Sorbonne and Bologna Declarations and now involving 40 countries, aims at establishing by 2010 the “European Higher Education Area”, based on “a system of easily readable and comparable degrees”. The actual implementation of this process and its relevance for the European labour market requires a convergence also of the accreditation procedures of educational programmes, that are still very different from a European country to the other. After defining the term “accreditation” in the context of the formation of engineers, this paper will discuss the present situation of accreditation of engineering educational programmes in Europe, and present some examples. The contribution of the Thematic Network E4 will be illustrated, and the most recent developments, aiming at a European-wide accreditation system, will be introduced.

Heritage buildings and seismic reliability

Within ‘heritage buildings’, a distinction can be made between ‘historical buildings’, i.e. those that can be defined as buildings of artistic an/or cultural value and which are found in significant numbers, and ‘monumental buildings’ that are truly unique. This paper summarizes existing procedures for the seismic reliability assessment of both heritage building categories: statistics can be applied to ‘historical buildings’ while it appears possible to evaluate the reliability of ‘monumental buildings’ only by subjective probabilities. Specific procedures are described for both cases.