No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Développement d'une base de données sur les scénarios de vieillissement des barrages (projet CASCAD)
Abstract
La moitié des quelques 250 barrages autorisés classés comme « intéressant la sécurité publique » a plus de 30 ans et est donc exposée à des phénomènes de vieillissement. À l'occasion des inspections réglementaires de contrôle dont font l'objet ces ouvrages, sont accumulées d'abondantes informations concernant leurs pathologies. Dans ce contexte, la recherche en cours (projet CASCAD) vise à aboutir à la création d'une base de données capable de stocker et de manipuler de telles informations dans l'objectif de comprendre et d'anticiper le comportement des barrages en service. L'originalité de l'approche repose sur l'élaboration d'un système d'informations avancé qui, à partir du comportement réel d'un barrage (base de données historique) et de comportements-types connus a priori (base de données de scénarios de vieillissement), permettra d'extraire le ou les scénarios les plus fidèles à l'ouvrage analysé. Une étape ultérieure consiste à étendre l'outil en vue de la prise en compte de scénarios d'interventions ou de réparations.
... Parmi cette population, les ouvrages intéressant la sécurité publique constituent un groupe d'environ deux cent cinquante ouvrages : ce sont des barrages dont la rupture aurait des conséquences graves pour les populations installées en aval. Approximativement la moitié de ces ouvrages -en terre, en béton ou en maçonnerie pour la plupart-a plus de trente ans et est donc sujette à des mécanismes de vieillissement (Cathala et al., 1998). Dans ce mémoire, nous illustrerons les approches sur les barrages en remblai. ...
The development of tools and methods able to manage the performance and safety of civil structures represents a main industrial issue and an interesting way of research. One of the difficulties relies on the necessity to combine various kinds of knowledge and data to assess the performance and safety. In this Ph.D. thesis, approaches contributing to assess dam performance are proposed. They are based on knowledge collected among an expert panel. The developments concern: * a deterministic method for the assessment of dam performance based on the collection, formalisation and aggregation of various kinds of knowledge; * a knowledge base related to phenomena that lead to damages in embankment dams. This base allows domain knowledge capitalization; * a method to analyse the origins of data imperfections; * a non-deterministic method for the assessment of performance that proceeds by representation and propagation of data imperfections. These methods lead to three user tools: a performance assessment interface, a data traceability system and a knowledge base concerning degradation phenomena. These approaches are illustrated on embankment dams and more specifically on the internal erosion mechanism.
This paper is devoted to the dynamic aspect of the IF02 conceptual model, an extension of the semantic IF0 model defined by S. Abite boul and R. Hull. Its original aspects are a "whole-event" approach, the use of construc- tors to express combinations of events, and the modularity and m-usability of specifiecl- tions in order to optimize the designer's work. Furthermore, it offers an overview of the rep resented behaviour. To complement the mod- elling part, IF02 includes a derivation com- ponent which performs the implementation of specifications by using an active DBMS.
In this paper, we propose a generic method for elaborating the behavioural specification dictionary of applications. It could apply in the context of various conceptual modelling approaches and take advantage of functionalities provided by associated CASE tools. The method is based on a meta-schema abstracting the behavioural concepts by using the structural abstractions of the chosen modelling approach. Once storage structures are generated from this meta-schema, they can be populated in an automated way by examining dynamic schemas specified by designers. The method is intended for dealing with particular applications in which behaviour must be preserved. 1 Motivations There are some kinds of applications in which behaviour must be represented not to be simulated or enhanced (through some executive programs or even active rules [Ha90, LNR87, TPC94b]) but to be preserved. Reasons behind "storing behaviour" are various. First of all, by keeping the whole trace of the applica...
Object-oriented modelling and design promote better understanding of requirements, cleaner designs and more maintainable systems. Often, books on related subjects rely on programming and coding, forcing readers to think in terms of the computer, and not the application. "Object-oriented Modeling and Design" emphasizes that object-oriented technology is more that just a way of programming. It applies techniques to the entire software development cycle. This volume presents a new object-oriented software development methodology - from analysis, through design, to implementation. Key features of the book include a focus on high-level, front-end conceptual processes of analysis and design, rather than just on the low-level, back-end implementation steps of programming; coverage of the entire development life cycle - analysis, design, implementation without a change of notation at each stage; a presentation of graphical notation and methodology independent of any particular programming language; case studies of industrial object-oriented applications developed by the authors; and examples and exercises that bring out fine points, summary lists of concepts and methodology steps, and almost 300 diagrams.
Le ministère de l'Environnement a demandé au Cemagref une étude des barrages placés sous sa responsabilité. Cette étude avait pour objet d'évaluer leur sécurité, leur surveilllance et leur entretien. Au total 361 barrages ont été visités dans 67 départements. Ils sont destinés à l'alimentation en eau, à l'irrigation, au contrôle des crues, au soutien des étiages ou aux loisirs. Ils sont gérés pour la plupart par de nombreux propriétaires dispersés sans compétences spécialisées, à la différence des barrages hydro-électriques (exploités par quelques organismes très spécialisés). Une réhabilitation des barrages anciens a été entreprise depuis vingt ans. Malgré cela, plusieurs barrages ne répondent pas entièrement aux critères "modernes" de sécurité : capacité d'évacuation des crues, état général et stabilité. Par ailleurs, la surveillance et l'auscultation de ces ouvrages doivent être nettement améliorées. / Cemagref was asked by the French Ministry for the Environment to assess the safety of, and the monitoring and maintenance programmes for, dams which come under the Ministry's authority. In total, 361 dams spread over 67 French departements were inspected. The dams fulfil a variety of functions including drinking water supply, irrigation water supply, flood control, low water level maintenance and sports and recreation. For the most part, the dams are owned by many various, widely dispersed owners, without any specialist expertise in dams technology, unlike in the case of hydroelectric dams which are used and managed by a few highly specialised organisations. Despite a dam restoration and upgrading programme which has been running for some twenty years, several dams still do not fully satisfy so-called modern design criteria, in particular with respect to floodwater evacuation capacity, overall dam condition and stability. In addition , the monitoring and assessment of these structures needs to be markedly improved.
A data model, called the entity-relationship model, is proposed. This model incorporates some of the important semantic information about the real world. A special diagrammatic technique is introduced as a tool for database design. An example of database design and description using the model and the diagrammatic technique is given. Some implications for data integrity, information retrieval, and data manipulation are discussed. The entity-relationship model can be used as a basis for unification of different views of data: the network model, the relational model, and the entity set model. Semantic ambiguities in these models are analyzed. Possible ways to derive their views of data from the entity-relationship model are presented.
A Database Modelling Approach for Dam Ageing Scenarios
- F Cathala
- P Meriaux
- P Royet
CATHALA, F., MERIAUX, P., ROYET, P., 1998. A Database Modelling Approach for Dam Ageing Scenarios,
Proceedings of International Symposium on New Trends and Guidelines on Dam Safety, Spanish Committe on
Large Dams, Barcelona 1998.
Essential components of risk assessment for dams, Workshop on Risk-Based Dam Safety Evaluations
- R Fell
FELL, R., 1997. Essential components of risk assessment for dams, Workshop on Risk-Based Dam Safety Evaluations, Trondheim (Norway).
International Commitee On Large Dam (ICOLD), 1993. Ageing of Dams and Appurtenant Works
- Collectif
Collectif, International Commitee On Large Dam (ICOLD), 1993. Ageing of Dams and Appurtenant Works.
France : ICOLD.
Guidelines for Reporting the Performance of Dams
- M W Mac Cann
MAC CANN, M.W. Jr et al., 1994. Guidelines for Reporting the Performance of Dams. Torrance : K&M
Company.
National Performance of Dams Program
- M W Mac Cann
MAC CANN, M.W. Jr et al., 1997. National Performance of Dams Program. Hydropowers & Dams. Issue Four,
1997 : 14.