scholarly journals FRAGILITY EVALUATION METHODOLOGY FOR TSUNAMI-BORNE DEBRIS IMPACT

2020 ◽  
pp. 9
Author(s):  
Hideki Kaida ◽  
Naoto Kihara
Keyword(s):  
Fragility Curves ◽  
Evaluation Methodology ◽  
Tsunami Height ◽  
Failure Frequency ◽  
Damage Probability ◽  
Tsunami Hazard Assessment ◽  
Tsunami Fragility ◽  
Probabilistic Tsunami Hazard Assessment ◽  
The Impact ◽  
Debris Impact

In the safe design and risk assessment of structures in coastal area, it is important to consider tsunami-borne debris impact. Recently, probabilistic analysis has become the preferred form of analysis because of the large aleatory and epistemic uncertainties associated with tsunami effects, which are not captured in deterministic scenario-based assessments. By performing both a probabilistic tsunami hazard assessment (PTHA) and a tsunami fragility assessment (TFA) on structures, their annual failure frequency can be determined. The TFA involves evaluation of the response (e.g. debris impact force exerted on the structure) and the capacity of the structure to resist tsunami effects. Then, a fragility curve shows conditional damage probability of the structure for the tsunami magnitude (e.g., discrete tsunami height around the focused area). This study proposes a TFA methodology for tsunami-borne debris impact, as this has not yet been sufficiently established. Evaluation of the impact speed and impact probability of debris considering various uncertainties in the response evaluation are described in particular detail. Moreover, an assessment of a coastal industrial site was performed and fragility curves and the annual failure frequency of structures against debris impact were shown.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/es-ny8eIUfc

scholarly journals Characteristics of building fragility curves for seismic and non-seismic tsunamis: case studies of the 2018 Sunda Strait, 2018 Sulawesi-Palu and 2004 Indian Ocean tsunamis

2020 ◽  
Author(s):  
Elisa Lahcene ◽  
Ioanna Ioannou ◽  
Anawat Suppasri ◽  
Kwanchai Pakoksung ◽  
Ryan Paulik ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Fragility Curves ◽  
Building Damage ◽  
Wave Period ◽  
Cumulative Distribution ◽  
Flow Depth ◽  
Ground Shaking ◽  
Damage Probability ◽  
The Impact ◽  
Banda Aceh

Abstract. Indonesia has experienced several recent tsunamis triggered by seismic as well as non-seismic (i.e., landslides) sources. These events damaged or destroyed coastal buildings and infrastructure, and caused considerable loss of life. The impact of tsunami characteristics on structural components can be represented by fragility curves. These cumulative distribution functions express the likelihood of a structure reaching or exceeding a damage state in response to a tsunami hazard intensity measure. Using numerical simulations and post-tsunami observations, we successfully reproduce the hydrodynamic features of the 2018 Sunda Strait and 2018 Sulawesi-Palu tsunamis for the first time. We then compare non-seismic building fragility curves from these events with the ones of the 2004 Indian Ocean tsunami (IOT) to provide a novel understanding of wave period, ground shaking and liquefaction impacts on the structural performance of buildings. Below 5-m flow depth, the 2004 IOT in Khao Lak/Phuket (Thailand), characterized by long wave period due to its seismic source, induces larger damage to buildings than the 2018 Sunda Strait tsunami, triggered by a landslide. We also note that for 4-m flow depth, the building damage probability is almost twice less in Khao Lak/Phuket than in Banda Aceh, where ground motion has been reported before the tsunami arrival. In addition, liquefaction events can cause significant building damage as in Palu, where constructions have been considerably affected by this phenomenon due to the 2018 Sulawesi earthquake. Below 2-m flow depth, the damage probability is greater in Palu than in the Sunda Strait but also in Banda Aceh, although this city has been affected by ground shaking, and then struck by the longer wave period of the IOT.

TSUNAMI HAZARD AND BUILDING DAMAGE ASSESSMENT IN THAILAND USING NUMERICAL MODEL AND FRAGILITY CURVES

2013 ◽  
Vol 07 (05) ◽  
pp. 1250028 ◽  
Author(s):  
ANAWAT SUPPASRI ◽  
FUMIHIKO IMAMURA ◽  
SHUNICHI KOSHIMURA
Keyword(s):  
Return Period ◽  
Fragility Curves ◽  
Propagation Model ◽  
Tsunami Height ◽  
Tsunami Propagation ◽  
Inundation Depth ◽  
High Resolution Satellite Images ◽  
Tsunami Fragility ◽  
2004 Tsunami ◽  
Inundation Model

Assessing the hazard and damage of a potential tsunami is an ongoing challenge in tsunami research. This study begins by simulating tsunami hazards using historical events. A tsunami propagation model is used to obtain the estimated maximum tsunami height along the west coast of Thailand for a rough return period, and rupture locations that have the potential to generate catastrophic tsunamis in Thailand for a specific return period are proposed. A tsunami inundation model is then performed to quantify each building's maximum inundation depth, using high-resolution satellite images to extract each building's location for the areas of interest located in southern Thailand. Nam Khem village and Patong beach are selected as study areas to represent village communities and tourist attractions, respectively. The model results are then used to obtain the numbers of exposed inhabitants and buildings for each earthquake return period. The developed tsunami fragility curves are applied to these figures to determine the number of potentially damaged buildings. The analysis suggests that the propagation model can be used to obtain rough estimations because it provided results similar to those of the inundation model. However, material type must be considered when fragility curves are used in a different country (i.e. reinforced concrete buildings in Thailand from the 2004 tsunami and wooden houses in Japan from the 2011 East Japan tsunami).

Methodology for Fragility Evaluation of a Seawall Against Tsunami Effects: Part 1 — Overflow and Physical Damage Associated With Tsunami Wave Pressure

2016 ◽  
Author(s):  
Hideki Kaida ◽  
Yoshinori Miyagawa ◽  
Naoto Kihara
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Tsunami Wave ◽  
Fragility Curves ◽  
Shear Capacity ◽  
Evaluation Methodology ◽  
Physical Damage ◽  
Wave Pressure ◽  
The Impact ◽  
Evaluation Accuracy

Successive safety improvements for nuclear power plants (NPPs) have been required by society as well as by regulatory agencies because of the nuclear accident at the Fukushima Daiichi Nuclear Power Plant due to the Great East Japan Earthquake and Tsunami. The establishment of a methodology for the fragility evaluation of seawalls is essential for developing a probabilistic risk assessment (PRA) for tsunamis that is applicable to NPPs where the hazard level of tsunamis is high. In the present study, fragility evaluation methods of reinforced concrete (RC) seawalls are documented. Two main damage modes of the seawall, namely overflow and physical damage caused by tsunami wave pressure, were the primary focus. Using the documented fragility evaluation methodology, a conceptual study for evaluating the fragility of a RC seawall against overflow and the impact of tsunami wave pressure is performed, and fragility curves are obtained by considering the following uncertainties: evaluation accuracy of the inundation level and tsunami wave pressure, density of the seawater, compressive strength of concrete, yield strength of reinforcement, and evaluation accuracy of the shear capacity.

scholarly journals Characteristics of building fragility curves for seismic and non-seismic tsunamis: case studies of the 2018 Sunda Strait, 2018 Sulawesi–Palu, and 2004 Indian Ocean tsunamis

2021 ◽  
Vol 21 (8) ◽  
pp. 2313-2344
Author(s):  
Elisa Lahcene ◽  
Ioanna Ioannou ◽  
Anawat Suppasri ◽  
Kwanchai Pakoksung ◽  
Ryan Paulik ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Fragility Curves ◽  
Indian Ocean Tsunami ◽  
Flow Depth ◽  
Damage State ◽  
Tsunami Damage ◽  
Earthquake Model ◽  
Tsunami Fragility ◽  
The Impact ◽  
Banda Aceh

Abstract. Indonesia has experienced several tsunamis triggered by seismic and non-seismic (i.e., landslides) sources. These events damaged or destroyed coastal buildings and infrastructure and caused considerable loss of life. Based on the Global Earthquake Model (GEM) guidelines, this study assesses the empirical tsunami fragility to the buildings inventory of the 2018 Sunda Strait, 2018 Sulawesi–Palu, and 2004 Indian Ocean (Khao Lak–Phuket, Thailand) tsunamis. Fragility curves represent the impact of tsunami characteristics on structural components and express the likelihood of a structure reaching or exceeding a damage state in response to a tsunami intensity measure. The Sunda Strait and Sulawesi–Palu tsunamis are uncommon events still poorly understood compared to the Indian Ocean tsunami (IOT), and their post-tsunami databases include only flow depth values. Using the TUNAMI two-layer model, we thus reproduce the flow depth, the flow velocity, and the hydrodynamic force of these two tsunamis for the first time. The flow depth is found to be the best descriptor of tsunami damage for both events. Accordingly, the building fragility curves for complete damage reveal that (i) in Khao Lak–Phuket, the buildings affected by the IOT sustained more damage than the Sunda Strait tsunami, characterized by shorter wave periods, and (ii) the buildings performed better in Khao Lak–Phuket than in Banda Aceh (Indonesia). Although the IOT affected both locations, ground motions were recorded in the city of Banda Aceh, and buildings could have been seismically damaged prior to the tsunami's arrival, and (iii) the buildings of Palu City exposed to the Sulawesi–Palu tsunami were more susceptible to complete damage than the ones affected by the IOT, in Banda Aceh, between 0 and 2 m flow depth. Similar to the Banda Aceh case, the Sulawesi–Palu tsunami load may not be the only cause of structural destruction. The buildings' susceptibility to tsunami damage in the waterfront of Palu City could have been enhanced by liquefaction events triggered by the 2018 Sulawesi earthquake.

scholarly journals Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

2015 ◽  
Vol 15 (11) ◽  
pp. 2557-2568 ◽  
Author(s):  
M. Wronna ◽  
R. Omira ◽  
M. A. Baptista
Keyword(s):  
Sea Level ◽  
Wave Height ◽  
Hazard Assessment ◽  
Test Site ◽  
Tsunami Hazard ◽  
Deterministic Approach ◽  
Flow Depth ◽  
Mean Sea Level ◽  
Tsunami Hazard Assessment ◽  
The Impact

Abstract. In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

scholarly journals An Evaluation Methodology for Interactive Reinforcement Learning with Simulated Users

Biomimetics ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Adam Bignold ◽  
Francisco Cruz ◽  
Richard Dazeley ◽  
Peter Vamplew ◽  
Cameron Foale
Keyword(s):  
Reinforcement Learning ◽  
Information Source ◽  
Human Interaction ◽  
Evaluation Methodology ◽  
External Information ◽  
Preliminary Evaluation ◽  
Learning Agents ◽  
Learning Agent ◽  
Knowledge Bias ◽  
The Impact

Interactive reinforcement learning methods utilise an external information source to evaluate decisions and accelerate learning. Previous work has shown that human advice could significantly improve learning agents’ performance. When evaluating reinforcement learning algorithms, it is common to repeat experiments as parameters are altered or to gain a sufficient sample size. In this regard, to require human interaction every time an experiment is restarted is undesirable, particularly when the expense in doing so can be considerable. Additionally, reusing the same people for the experiment introduces bias, as they will learn the behaviour of the agent and the dynamics of the environment. This paper presents a methodology for evaluating interactive reinforcement learning agents by employing simulated users. Simulated users allow human knowledge, bias, and interaction to be simulated. The use of simulated users allows the development and testing of reinforcement learning agents, and can provide indicative results of agent performance under defined human constraints. While simulated users are no replacement for actual humans, they do offer an affordable and fast alternative for evaluative assisted agents. We introduce a method for performing a preliminary evaluation utilising simulated users to show how performance changes depending on the type of user assisting the agent. Moreover, we describe how human interaction may be simulated, and present an experiment illustrating the applicability of simulating users in evaluating agent performance when assisted by different types of trainers. Experimental results show that the use of this methodology allows for greater insight into the performance of interactive reinforcement learning agents when advised by different users. The use of simulated users with varying characteristics allows for evaluation of the impact of those characteristics on the behaviour of the learning agent.

scholarly journals Vulnerability Assessment of Buildings due to Land Subsidence Using InSAR Data in the Ancient Historical City of Pistoia (Italy)

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2749 ◽  
Author(s):  
Pablo Ezquerro ◽  
Matteo Del Soldato ◽  
Lorenzo Solari ◽  
Roberto Tomás ◽  
Federico Raspini ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Central Italy ◽  
Sar Interferometry ◽  
Ground Subsidence ◽  
Public And Private ◽  
Radar Images ◽  
Spatial Deformation ◽  
Damage Probability ◽  
Medium Resolution ◽  
Vertical Displacements

The launch of the medium resolution Synthetic Aperture Radar (SAR) Sentinel-1 constellation in 2014 has allowed public and private organizations to introduce SAR interferometry (InSAR) products as a valuable option in their monitoring systems. The massive stacks of displacement data resulting from the processing of large C-B and radar images can be used to highlight temporal and spatial deformation anomalies, and their detailed analysis and postprocessing to generate operative products for final users. In this work, the wide-area mapping capability of Sentinel-1 was used in synergy with the COSMO-SkyMed high resolution SAR data to characterize ground subsidence affecting the urban fabric of the city of Pistoia (Tuscany Region, central Italy). Line of sight velocities were decomposed on vertical and E–W components, observing slight horizontal movements towards the center of the subsidence area. Vertical displacements and damage field surveys allowed for the calculation of the probability of damage depending on the displacement velocity by means of fragility curves. Finally, these data were translated to damage probability and potential loss maps. These products are useful for urban planning and geohazard management, focusing on the identification of the most hazardous areas on which to concentrate efforts and resources.

Generating Random Earthquake Events for Probabilistic Tsunami Hazard Assessment

2016 ◽  
Vol 173 (12) ◽  
pp. 3671-3692 ◽  
Author(s):  
Randall J. LeVeque ◽  
Knut Waagan ◽  
Frank I. González ◽  
Donsub Rim ◽  
Guang Lin
Keyword(s):  
Hazard Assessment ◽  
Tsunami Hazard ◽  
Tsunami Hazard Assessment ◽  
Probabilistic Tsunami Hazard Assessment

Debris/Micrometeoroid Impacts and Synergistic Effects on Spacecraft Materials

MRS Bulletin ◽  
2010 ◽  
Vol 35 (1) ◽  
pp. 41-47 ◽  
Author(s):  
E. Grossman ◽  
I. Gouzman ◽  
R. Verker
Keyword(s):  
Space Debris ◽  
Synergistic Effects ◽  
Degradation Mechanism ◽  
Space Environment ◽  
Materials Properties ◽  
Gas Gun ◽  
Naturally Occurring ◽  
Space Activity ◽  
The Impact ◽  
Debris Impact

AbstractIn the last 40 years, the increased space activity created a new form of space environment of hypervelocity objects—space debris—that have no functional use. The space debris, together with naturally occurring ultrahigh velocity meteoroids, presents a significant hazard to spacecraft. Collision with space debris or meteoroids might result in disfunction of external units such as solar cells, affecting materials properties, contaminating optical devices, or destroying satellites. The collision normally results in the formation of additional debris, increasing the hazard for future missions. The hypervelocity debris effect is studied by retrieving materials from space or by using ground simulation facilities. Simulation facilities, which include the light gas gun and Laser Driven Flyer methods, are used for studying the materials degradation due to debris impact. The impact effect could be accelerated when occurring simultaneously with other space environment components, such as atomic oxygen, ultraviolet, or x-ray radiation. Understanding the degradation mechanism might help in developing materials that will withstand the increasing hazard from the space debris, allowing for longer space missions. The large increase in space debris population and the associated risk to space activity requires significant measures to mitigate this hazard. Most current efforts are being devoted to prevention of collisions by keeping track of the larger debris and avoiding formation of new debris.

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