Méthodologie intégrée d'évaluation de la fonctionnalité post-sismique des hôpitaux

Abstract

When an earthquake occurs, hospitals are expected to remain functional as they play a crucial role in emergency care operations. This ability to ensure the continuity of quality operations while ensuring the safety of occupants during and after an earthquake defines the concept of post-earthquake functionality. Hospital functionality relies on the good performance of the structure and a large number of operational and functional components (OFCs) including building content and equipment. The result is a set of systems and subsystems connected by their interfaces and usually described as complex. Therefore, the global seismic performance cannot be achieved by a simple sum of subsystem vulnerability or component indices. In Canada, the objectives of structural and OFCs performance are respectively defined by the National Building Code in its 2010 version and the Canadian standard "CSA S832-06-14, Seismic risk reduction of OFCs of buildings". Immediate occupancy of post disaster buildings is mandatory for rare earthquakes with a hazard level of 2% in 50 years, and the full functionality for more frequent events (10% in 50 years) should be maintained. These performance levels constitute the framework of development for the assessment methodology. This has been the main impetus for assessing the effects of damage to components on the interrelated systems functionality under these hazard levels. The approach used in this thesis is based on defining the hospital as a complex system, in which critical sub-systems and their interrelations are identified and modelled in a qualitative phase. The thesis introduces a post-earthquake functionality index (PFI) computed through subsequent quantitative analysis. In order to establish the evaluation framework of the hospitals post-earthquake functionality, the qualitative phase includes a detailed literature review on the seismic performance of hospitals, seismic evaluation methods and reliability analysis, including the fault tree analysis method (FTA). This phase is completed by the assessment of seismic vulnerability of structures and OFCs of two hospitals in Montreal, using Canadian existing methods. Hospital case studies are the Montreal General Hospital and Hôpital Rivière-des-Prairies, in which six critical sub-systems, identified by managers, were selected for the development of a global database. Fault tree models of sub-systems and structural characterization of buildings are the result of this process. The quantitative phase is conducted as a parametric study combined with a probabilistic approach. It is based on the developed global database and the combination of several tools: seismic index methods, fragility curves and fault trees. The study of post-earthquake functionality through risk index and probability of damage is a logical and practical approach in a context of data scarcity in Quebec. It identifies the effects of risk factors and failure of systems, and hence helps to develop a better understanding of these issues. The probability of damage alongside the risk levels are grouped into a risk matrix to develop PFI interpretation criteria, which facilitates risk interpretation to support decision making for mitigation action. The methodology can be used as comprehensive approach to conduct large-scale assessment. Finally, a validation process and case studies are presented in the thesis. Although the comparison with external data is limited because of the state of research on CFO performance, the results justify the choice of input parameters and confirm the variability of the PFI index. The objectives of case study are twofold: assessment of post-earthquake functionality of critical systems, and optimisation of index interpretation. It appears that the overall methodology gives a reliable picture of the earthquake survivability of Montréal hospitals.

Date	8 Oct 2015
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Marie-José Nollet (Supervisor) & Ghyslaine McClure (Co-supervisor)