Optical (Camera-Based) Technology for Seismic Risk Assessment

Author(s):  
Thomas Wischgoll ◽  
Tara C. Hutchinson ◽  
Falko Kuester

Due to an increasing bandwidth for data transport in recent computers, optical (camera-based) sensors with high frame rates and reasonable resolutions can nowadays be used with off-the-shelf computers. By monitoring buildings, bridges and other infrastructure with such sensors, they can greatly assist in risk assessment. In this paper, several field application examples are described, largely encompassing the areas of civil infrastructure monitoring. Optical (camera-based) systems can be particularly powerful for monitoring both local and global movements within a scene or environment. Therefore, natural hazards induced by such movements, for example during earthquake events, are an important application area for these new technologies. First, a clear definition of seismic risk assessment is provided. Subsequently, two important fields where cameras may be useful in seismic risk assessment are described. Specifically, the context of (i) early warning systems and (ii) post-earthquake assessment are addressed. An example of using the optical record from a series of large shake table tests is provided and comparison with other methods discussed.

2021 ◽  
Author(s):  
Vitor Silva

<p>The increase in the global population, climate change, growing urbanization and settlement in regions prone to natural hazards are some of the factors contributing to the increase in the economic and human losses due to disasters. Earthquakes represent on average approximately one-fifth of the annual losses, but in some years this proportion can be above 50% (e.g. 2010, 2011). This impact can affect the sustainable development of society, creation of jobs and availability of funds for poverty reduction. Furthermore, business disruption of large corporations can result in negative impacts at global scale. Earthquake risk information can be used to support decision-makers in the distribution of funds for effective risk mitigation. However, open and reliable probabilistic seismic risk models are only available for less than a dozen of countries, which dampers disaster risk management, in particular in the under-developed world. To mitigate this issue, the Global Earthquake Model Foundation and its partners have been supporting regional programmes and bilateral collaborations to develop an open global earthquake risk model. These efforts led to the development of a repository of probabilistic seismic hazard models, a global exposure dataset, and a comprehensive set of fragility and vulnerability functions for the most common building classes. These components were used to estimate relevant earthquake risk metrics, which are now publicly available to the community.</p><p>The development of the global seismic risk model also allowed the identification of several issues that affect the reliability and accuracy of existing risk models. These include the use of outdated exposure information, insufficient consideration of all sources of epistemic and aleatory uncertainty, lack of results regarding indirect human and economic losses, and inability to forecast detailed earthquake risk to the upcoming decades. These challenges may render the results from existing earthquake loss models inadequate for decision-making. It is thus urgent to re-evaluate the current practice in earthquake risk loss assessment, and explore new technologies, knowledge and data that might mitigate some of these issues. A recent resource that can support the improvement of exposure datasets and the forecasting of exposure and risk into the next decades is the Global Human Settlement Layer, a collection of datasets regarding the built-environment between 1974 and 2010. The consideration of this type of information and incorporation of large sources of uncertainty can now be supported by artificial intelligence technology, and in particular open-source machine learning platforms. Such tools are currently being explored to predict earthquake aftershocks, to estimate damage shortly after the occurrence of destructive events, and to perform complex calculations with billions of simulations. These are examples of recent resources that must be exploited for the benefit of improving existing risk models, and consequently enhance the likelihood that risk reduction measures will be efficient.</p><p>This study presents the current practice in global seismic risk assessment with all of its limitations, it discusses the areas where improvements are necessary, and presents possible directions for risk assessment in the upcoming years.</p>


2020 ◽  
Author(s):  
Vitor Silva

<p>The increase in the global population, climate change, growing urbanization and settlement in regions prone to natural hazards are some of the factors contributing to the increase in the economic and human losses due to disasters. Earthquakes represent on average approximately one-fifth of the annual losses, but in some years this proportion can be above 50% (e.g. 2010, 2011). This impact can affect the sustainable development of society, creation of jobs and availability of funds for poverty reduction. Furthermore, business disruption of large corporations can result in negative impacts at global scale. Earthquake risk information can be used to support decision-makers in the distribution of funds for effective risk mitigation. However, open and reliable probabilistic seismic risk models are only available for less than a dozen of countries, which dampers disaster risk management, in particular in the under-developed world. To mitigate this issue, the Global Earthquake Model Foundation and its partners have been supporting regional programmes and bilateral collaborations to develop an open global earthquake risk model. These efforts led to the development of a repository of probabilistic seismic hazard models, a global exposure dataset, and a comprehensive set of fragility and vulnerability functions for the most common building classes. These components were used to estimate relevant earthquake risk metrics, which are now publicly available to the community.</p><p>The development of the global seismic risk model also allowed the identification of several issues that affect the reliability and accuracy of existing risk models. These include the use of outdated exposure information, insufficient consideration of all sources of epistemic and aleatory uncertainty, lack of results regarding indirect human and economic losses, and inability to forecast detailed earthquake risk to the upcoming decades. These challenges may render the results from existing earthquake loss models inadequate for decision-making. It is thus urgent to re-evaluate the current practice in earthquake risk loss assessment, and explore new technologies, knowledge and data that might mitigate some of these issues. A recent resource that can support the improvement of exposure datasets and the forecasting of exposure and risk into the next decades is the Global Human Settlement Layer, a collection of datasets regarding the built-environment between 1974 and 2010. The consideration of this type of information and incorporation of large sources of uncertainty can now be supported by artificial intelligence technology, and in particular open-source machine learning platforms. Such tools are currently being explored to predict earthquake aftershocks, to estimate damage shortly after the occurrence of destructive events, and to perform complex calculations with billions of simulations. These are examples of recent resources that must be exploited for the benefit of improving existing risk models, and consequently enhance the likelihood that risk reduction measures will be efficient.</p><p>This study presents the current practice in global seismic risk assessment with all of its limitations, it discusses the areas where improvements are necessary, and presents possible directions for risk assessment in the upcoming years.</p>


2019 ◽  
Vol 1 (Special Issue on First SACEE'19) ◽  
pp. 55-75
Author(s):  
Fabio Sabetta

In this paper, the main features of the policies adopted in Italy for seismic risk reduction are discussed. Particular attention is given to the Pre-disaster prevention activities such as the implementation of the building code, the seismic risk assessment for a priority scale of intervention, tax incentives and public funding for the vulnerability reduction of the existing buildings, information to population and school education, technical training of experts. The phases of response and post-disaster activities, including emergency management, search and rescue, loss scenarios, and safety assessment of buildings, are also discussed taking example from the most recent devastating earthquakes in Italy (L.Aquila 2009, Amatrice 2016).


2011 ◽  
Vol 05 (01) ◽  
pp. 31-45 ◽  
Author(s):  
T. IMAI ◽  
S. WADA ◽  
T. KOIKE

In order to keep the existing lifeline network system at a favorable seismic performance level, it is necessary to carry out retrofitting activities. This study proposes a seismic risk assessment method for the existing deteriorated lifeline network system based on the probability of system performance failure. Numerical simulations are carried out for the existing water distribution network system for several seismic investment strategies to support the decision making of seismic disaster mitigation planning. Effective planning of seismic retrofitting activities and disaster mitigation for the existing lifeline system can be realized using the newly developed assessment method.


2008 ◽  
Vol 12 (sup2) ◽  
pp. 199-210 ◽  
Author(s):  
Dominik H. Lang ◽  
Sergio Molina-Palacios ◽  
Conrad D. Lindholm

2018 ◽  
Vol 45 (9) ◽  
pp. 717-727 ◽  
Author(s):  
Reza Fathi-Fazl ◽  
Eric Jacques ◽  
Zhen Cai ◽  
Bessam Kadhom ◽  
Bassem Saassouh ◽  
...  

This paper presents a preliminary seismic risk screening tool to identify buildings whose superior structural and non-structural seismic performance in regions of low seismicity can be assessed based on several key attributes. The tool is designed to exempt buildings from detailed seismic risk assessment if key exemption criteria are met. The exemption criteria are based on: a seismic categorization system linked to anticipated building damage and seismicity; whether or not the building was designed using modern seismic design provisions; and the remaining time that the building will be occupied. The tool also provides a second list of criteria, which if satisfied, will automatically trigger further detailed seismic risk assessment. The decisions rendered by the tool regarding the expected seismic performance of a building are evaluated against the next level of seismic risk screening tool to ensure the consistency. A flowchart is presented to facilitate adoption of the tool by practicing engineers and other end-users.


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