(2011), "Thesis title: Estimation of malfunction of a healthcare facility in case of earthquake", International Journal of Disaster Resilience in the Built Environment, Vol. 2 No. 3. https://doi.org/10.1108/ijdrbe.2011.43502caa.002
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Copyright © 2011, Emerald Group Publishing Limited
Thesis title: Estimation of malfunction of a healthcare facility in case of earthquake
Article Type: PhD abstracts From: International Journal of Disaster Resilience in the Built Environment, Volume 2, Issue 3
1 Context and aim
The considerable development humanity has reached in all sectors made life safer and more comfortable; however, despite this development, natural hazards still pose a threat to properties and even lives. Researchers have been searching for ways to reduce the impact of natural hazards on human life. Consequently, strategies, approaches and techniques have been developed and in cases enforced by legislations. These resulted in a substantial reduction of the mortality rate and, accordingly, increased the number of injuries and highlighted the importance of medical care post hazards. Amongst natural hazards, the particularity of earthquakes is due to the significant impact on properties, infrastructure, and society caused in a very short time. Following an earthquake, hospitals are required to deal immediately with earthquake-related-injuries which number reaches 97 percent of total injuries within the first 30 minutes (Gunn, 1995). However, experience demonstrated that health and care facilities are not always available due to the damage they withstand. The damage experienced is often classified into structural, non-structural and functional. Despite the techniques developed to improve the resilience of these components, there are many facilities around the world that are still vulnerable and need to be assessed in order to identify their vulnerabilities and thus improve resilience.
The literature reveals many assessment methodologies classified into pre- and post-disaster techniques. Post-disaster techniques are conducted to identify buildings level of safety; whilst, pre-disaster assessment techniques are often conducted to evaluate the resilience of the facility to specific scenarios. They provide vulnerability information and evidence for authorities, managers and engineers to retrofit and develop strategies for risk reduction. Their forms (qualitative or quantitative) vary according to their purposes and the way they are developed which can be based on observed vulnerability, expert opinions, simple analytical models, score assignment or detailed analysis procedure (Lang, 2002). Some methodologies have been developed to provide preliminary and comprehensive information about facility resilience such as in WHO (2006); whilst others to identify vulnerable engineering systems such as that of Johnson et al. (1999). Both these methodologies provide excellent information about the resilience of facilities, but limited in terms of prediction of inoperability immediately after an earthquake and reflection of the complexity and interconnectivity of hospital systems. The current study aims to develop a universal assessment methodology that reflects the complexity and interconnectivity of hospital internal systems, and able to predict and quantify the damage of a healthcare facility in earthquakes. Four steps were set to reach this goal:
understand what are the most common factors affecting the operation of healthcare facilities;
study the performance of most critical systems;
develop the fragility model for each of these systems; and
develop fragility model for the entire facility.
2 Post-earthquake hospital performance
The study commenced by analysing impact of damage to healthcare facilities in several countries caused by many earthquakes to identify what is common and specific. Data were collected through thorough literature review, site visits, questionnaires and interviews. The findings demonstrated that the level of structural and architectural damage varies among facilities due to many issues such as construction material and technique, design, and compliance to legislations. On the other hand, the findings demonstrate that lifelines (i.e. utilities) and equipment performance was comparable within most facilities due to the similarity of installations, which often are not protected by codes. The study focus therefore covers lifeline systems and equipment stability.
3 Performance of critical systems
The lifeline study aims to identify the most influential lifeline, assess its performance and suggest solutions to enhance its resilience. A questionnaire survey was sent to over 100 facilities following three major earthquakes in northern Japan. The responses were screened and analysed using a mathematical approach to combine most common lifeline systems in one equation that quantified the interconnectivity of systems and enabled the prediction of lifeline shortage on the operation of facilities. Further analysis was conducted and findings demonstrated that electric power is the most influential lifeline. To mitigate risks of lifeline failure the World Health Organization and the Pan America Health Organization recommend duplication and use of alternative sources, consequently many facilities were equipped with conventional alternative sources such as fuel power generators. The fuel power generators, however, have not been as reliable as expected. As such, a comparative study was conducted, to compare the performance of power generators and photovoltaic (PV) systems. The comparison concluded that PV systems are an excellent solution to reduce the pressure on the power demand, provide a low impact solution to preserve the environment and thus enhance the resilience and sustainability of hospitals.
b. Equipment performance
Potential impact of equipment stability includes disruption to health care delivery, untidiness of hospital space and potential initiation for complex incidents, such as hazard material spills and explosions. This section conducted a theoretical study, strengthened by experimentation, to understand the response of equipment to dynamic loads and identify the best technique to reduce equipment instability. Wheeled equipment and shelves were selected for the study due to their excessive use in hospitals. The findings demonstrated that wheeled equipment slide when wheels are unlocked and rock when locked due to their low natural frequency, they stabilise more in high frequencies and destabilise when exposed to low frequencies. Whilst, connecting shelves to their supports (i.e. building structure) leads to their stability.
4 Development of fragility
Facility fragility is assumed as a combination of hospital internal system fragilities which in turn depend on maximum input accelerations (i.e. ground and floor accelerations) and predominant frequencies. A set of criteria was developed for each case upon which internal system is considered to be safe (fragility f=0) or damaged (fragility f=1). Results were plotted in fragility-acceleration-frequency diagrams; a diagram for each system, based on which engineers identify vulnerabilities and clinical staff dispatch injuries. The diagrams were then combined into a single diagram to provide decision makers with the appropriate evidence to improve the resilience of local, regional and national healthcare system and plan better for more resilient healthcare in earthquakes:
Candidate name: Nebil Achour
Department: Division of Civil and Environmental Engineering
College/university: Graduate School of Natural Science and Technology, Kanazawa University
University city, state, country: Kanazawa, Ishikawa, Japan
Month/year completed: March 2007
Language of the thesis: English
Thesis supervisor(s): Professor Masakatsu Miyajima and Professor Masaru Kitaura
Postal address (current): School of Civil and Building Engineering, Loughborough University, Ashby Road, Loughborough, Leicestershire, UK
Phone (current): 0044 1509 223641