Evaluation de stratégies pour la gestion du risque sismique du bâtiment

This document presents the results of a research on seismic risk management. It echoes the worldwide trend of increasing awareness of the importance of this risk and represents a contribution to the effort of research. In order to manage risk in a rational way, it is necessary to quantify it. The first part of this research consists in evaluating the seismic risk of a portfolio of buildings. The selected portfolio is the city of Aigle located in the center of the Swiss Alps. The evaluation was based on a seismic inventory of the city, enabling, through a global approach, to consider the behavior of the buildings. Different losses (life, building, furniture) could be estimated for several scenarii of seismic hazards intensities. Knowing the probability of occurency of these intensities, as well as the uncertainties of the constitutive parameters, it was then possible to quantify the risk affecting the selected portfolio of buildings. The maximum potential loss for the studied area was also estimated. As a result, a reproducible risk estimation model was developed with its constitutive parameters. The obtained results provide information on potential losses, on the level of insurance premium as well as on elements of reinsurance. Seismic risk management, because of its complexity and the extent of the consequences ensuing from major events, requires a different approach from other natural risks. In the second part of this research, management tools are therefore developed in order for decision makers to face these particularities. A comprehensive management framework is elaborated. This framework makes it possible to deal with the complexity of seismic risk, which not only stems from its inherent specificities but also from the multiplicity of decision criteria as well as the variety of actors within the system. The definition of protection objectives receives special attention in this research. Construction codes usually fix safety levels for new constructions. For existing buildings on the other hand, there are no such provisions. The present research proposes a method for fixing this protection level. This method also considers the often contradictory principles of precaution and proportionality. An innovative catalogue of mitigation measures are then proposed, classified according to their influence on the components of risk. These measures can be focused on prevention, protection or intervention. They have an impact on the hazard, the vulnerability or on the exposed value at the considered risk. Consequently, different strategies are built to be later evaluated and compared. For this work, a strategy is considered to be a panel of measures that have an impact on the constitutive elements of risk. The decision-making process is regarded as a systemic approach considering the multiplicity of decision criteria and actors. A multicriteria analysis method based on an outranking philosophy is adopted for the comparison. Criteria are proposed for individual buildings as well for a portfolio of buildings. Applications of the decision-making process on pilot projects illustrate the methodology and provide practical recommendations. The pilot project of the city of Aigle was the guideline for the presented research, which aimed to deal with the complexity of seismic risk management in the most comprehensive way possible.

Du savetier au financier: la famille Borel, de Neuchâtel à San Francisco

The Borel Family From Neuchâtel to San Francisco : From shoemaker to banker Did you know that the Cable Car was owned by Swiss citizens? BACKTRACKING : PRIVATE FINANCING OF PUBLIC METROPOLITAN INFRASTRUCTURES Executive Summary: Did you know that one of San Francisco most famous fixtures, the Cable car, was owned by Swiss citizens? Through this detailed study of the Borel family, and its business and investment plans we will observe an example of private financing of public metropolitan infrastructures in the 19th Century and see if it can teach us lessons for tomorrow’s needs? TOPICS Looking at today’s infrastructures, one does not always remember how much work contracting firms had to accomplish in order to produce our contemporary standard of urban comfort . What is to be said of yesterday’s planners or engineers and the credit they deserve? We often hear stories of local events brought to epic proportions, but who are the responsible players who really proved the feasibility of regional infrastructures? Who actually did support, sponsor or finance such achievements? The present study is a trial to propose a new view over such apparently hidden business phenomenons. This research shows us an inspiring case-study of local entrepreneurs who gather key success-factors. The author concentrates on the economic aspect of infrastructure financing to which modern metropolitan society owes its specific urban growth. Contemporary challenges such as job creation, globalisation, technology transfer and local economic development are all interconnected to metropolitan development. XIXTH CENTURY METROPOLITAN INFRASTRUCTURES FINANCING Le Temps, 30th July 1998, D. Masmejan : «Alfred Borel, Auguste’s elder son, enters the finance world. He meets an extraordinary businessman fate. His understanding of the economic impact of the Californian Gold Rush allows him to seize the opportunity of the westward American expansionism. He sails to San Francisco in 1855 where he is the founder of the «Alfred Borel & Company», followed in 1856 by a Mortgage fund (the “Caisse Hypothécaire” bank). The same year sees the foundation of Credit Suisse in Zurich. Alfred Borel investment bank participates in very important infrastructure projects in California and elsewhere in the second half of the XIXth century. At first, its investment into the worldwide famous San Francisco Cable Car is marginal and then becomes overwhelming. Other investments include the “Los Angeles Railway Company” or the “United Railroad Company”, the San Francisco Waterworks, other banks and real estate.» DETAILED RESEARCH ALLOWING TO UNDERSTAND FINANCIAL DECISION MAKING The author reviews financial decision-making through personal correspondence and private accounting in some of those completely documented yearly archives. The «sixth Switzerland» well-connected to the Presbyterian «Huguenot International» cosmopolitan network leads us to detailed research and discoveries. The accounting of 1866 to 1884 goes through the 3rd and 4th San Francisco City real estate crises that the mortgage bankers Borel brothers had to endure. Alfred Borel faced the 2nd Californian real estate crisis (which resulted from the first loss of public interest in gold mines in the years 1854-1858). Then he went back to Switzerland after the death of his father and uncles in order to reconstitute the Swiss end of the pipe connecting his bank’s investors to the Borel family network. He left duty of the day-to-day San Francisco business to his younger brother Antoine after having set up asset management rules. Together both brothers explored new ways of diversifying the investment of the funds they are managing and place them into infrastructures networks. Taking shares «upstream» into equipment industries (for instance the wire works delivering the precise traction rope of cable cars) or other real estate assets, allowed them to guarantee superior interests payments to European investors or creditors in comparison with other financial markets. This anticyclical economic strategy set up their financial success that occurred during the 5th local economic recession, which coincides with the beginning of the big worldwide Victorian economic crisis (1880-1895). UNIQUE SPECIFICITY OF THIS RESEARCH This research process is rarely accomplished in engineering and architecture schools, construction and infrastructures institutes or research centers. The integrity of construction professionals precludes their questioning « where does the whole process originate from?». Builders ultimately considered themselves as «honest craftsmen» that have to dedicate their energy and resources to the proper technical execution of the clients wishes and orders. Customers duty is then to write the project’s specifications and thus to initiate its process. The author of this case-study demonstrates the feasibility of comparisons between similar structural change periods in the XIXth century and the years 1990-2000. Hence, a new theme of interdisciplinary studies for engineers could be implemented by promoting this systemic approach between urban infrastructure financiers, suppliers and users. Last but not least, the insider observations and outsider revelations which are featured in this work are seldom considered in an engineering historical approach. It is not often that an author with a contemporary outsider vision has access to family archives that entirely document bicentennial confidential banker correspondence.

EPFL1999

Optimalisation des formes d'organisation dans l'industrie de la construction

Philippe Pot

A piece of work carried out by the construction industry, whether a building or a civil engineering project, is not a mass-produced item. It is always a unique piece of work, by dint of its response to the specific needs of the owner and its potential users, its integration or otherwise into a built environment, and its construction on ground whose geo-technical properties are always specific. This unique piece of work, carried out outside on a site subject to numerous hazards, must nevertheless meet the programme's fixed objectives first time round. Unfortunately, unlike most industrial products, it is usually, even nowadays, the outcome of a fragmented approach: designers and builders of the shell of the building and those engaged in the finishings are in fact involved in a segmented and sequential process, without any real interaction between the various disciplines, to the detriment of overall quality and the cost of the end-product. The author of this thesis has had the opportunity, in his professional career in the management of major construction companies, of testing most organisational forms in the sector. He has observed that, depending on the model chosen, they exercise a more or less beneficial effect on quality, costs and time-frames for completing the works, as well as on the capacity for innovation of the participants themselves. The first objective of the thesis was to analyse the strengths and weaknesses of the most common organisational models in the construction industry and to identify factors in the success of the construction process. The second objective was to suggest an original organisational model which would make optimum use of these factors, taking into account modern organisational theory and project management. The first section of the thesis is an historical study of organisational forms of construction from antiquity to the modern times, and examines in particular the relationships between those actively and directly involved (owner, designers and builders) and their relationships in turn with those involved indirectly (users, public administration, finance providers, environmental and heritage protection organisations, laws and standards, etc.). This historical perspective makes a useful contribution because, although much has been written on architecture and architects, especially the most famous among them, and sometimes on engineers, work looking systematically at the organisational forms used in the construction industry over the centuries is rare. This study demonstrates that the fragmented organisation of construction characteristic of the 20th century is merely an accident in the long history of construction; the twenty-five preceding centuries almost always favoured close collaboration between designers and builders and the wonderful works they left behind demonstrate the wisdom of this approach. Study of the history also provides us with a list of the main success factors and the demands to which the successful organisation of construction must respond. The second part endeavours to verify the relevance of the needs drawn, in the light of modern organisational theory, from project management and creativity, and to complete the list. It goes on to analyse on that basis the strengths and weaknesses of the organisational models most commonly used in the modern construction industry and demonstrates that organisation as a design and build, is in the best position at this stage in the research to meet the needs of owners. The third section verifies, through case studies of five pieces of work recently completed or under construction, whether this organisational model effectively satisfies the expectations of those involved in the construction project, simultaneously examining potential improvements. To that end, a series of interviews was conducted in each case study, with a view to eliciting the views of representative participants: owner, operator, user, project manager, architect, engineer and sub-contracting trades. The process was completed with an analysis of the attitude of some public sector owners to the design and build organisational model. Finally, the lessons drawn from these case studies were used to complete the list of success factors already identified. A final section sets out an original organisational model named Integrated Construction Management (ICM), which recommends an inter-disciplinary approach to construction and responds to the success factors identified in the first three sections. It involves a new division of the production process, which provides the owner with a broader and more cost-effective range of innovative architectural and construction options. It also delivers a series of practical recommendations to assist in the application of the proposed model. In conclusion, Integrated Construction Management places the owner at the centre of a transparent and progressive production process, simultaneously removing the majority of the risks involved in construction. Through its inter-disciplinary approach, it offers innovative solutions together with improvements to the overall quality of the piece of work itself on favourable economic terms. Finally, it enables the owner to take informed decisions and to use his or her financial resources as and when the feasibility of the project is confirmed. It is hoped that, as a result, these advantages will be demonstrated through pilot projects carried out using the ICM model, which will without doubt make possible further improvements in performance.

EPFL2005

Methodology for Comparing Strategies in Seismic Risk Management of Existing Building Population

Marc Badoux, Vincent Pellissier

This paper presents the approach of a current research project at the EPFL in the area of seismic risk management. The objective of the project is to define and test a methodology for the quantitative characterization and comparison of intervention strategies in a risk management framework. A tool to assist in the selection of an intervention strategy will be developed. The project includes a pilot project for the seismic risk management of a small town in Switzerland. The selection of an intervention strategy raises two categories of problems. The first is connected to the quality of the information available. The second is connected to the variety of the criteria integrated in the decision-making process. The use of multi-criteria methods facilitates decision-making. Concerning the type of multi-criteria methods, experience has drawn attention to the quality of the “surclassement” methods (e.g. ELECTRE), because they can deal equally with qualitative or quantitative criteria.

20th European Regional Earthquake Engineering Seminar2001

Du savetier au financier: la famille Borel, de Neuchâtel à San Francisco

EPFL1999

Optimalisation des formes d'organisation dans l'industrie de la construction

Philippe Pot

EPFL2005