scholarly journals ASSESSMENT OF HYDRAULIC LOADS AND DERIVATION OF FAILURE PROBABILITIES AS A BASIS FOR THE DEERMINATION OF FRAGILITY CURVES FOR FLOOD DEFENCE DUNES

2012 ◽  
Vol 1 (33) ◽  
pp. 63
Author(s):  
Angelika Gruhn ◽  
Dörte Salecker ◽  
Peter Fröhle ◽  
Holger Schüttrumpf ◽  
Frank Thorenz
Keyword(s):  
Failure Probability ◽  
Flood Risk ◽  
Fragility Curves ◽  
Storm Surges ◽  
Damage Analysis ◽  
The European Union ◽  
First Results ◽  
Flood Defence ◽  
Settlement Areas ◽  
Failure Probabilities

Low lying coastal areas have always been preferred settlement areas as well as trading and industrial areas. Unfortunately, those areas are strongly endangered by extreme storm surges. In the event of a flood defence failure, protected areas are flooded and damages have to be expected. For the assessment and management of flood risk, the European Union approved the “Directive of the European Parliament and the Council on the assessment and management of flood risk”. As one part of a risk and damage analysis the risk of flooding - being the product of failure probability of a certain flood defence and the damages resulting from a failure of this flood defence - has to be determined. One possibility for the assessment of the failure probability is provided by fragility curves. A method for the derivation of fragility curves for flood defence dunes is described. Hence, the applied dune erosion model as well as the method for the derivation of the required input data is explained. Furthermore, first results of the calculation of failure probabilities and fragility curves are presented.

scholarly journals FAILURE PROBABILITY OF FLOOD DEFENCE STRUCTURES/ SYSTEMS IN RISK ANALYSIS FOR EXTREME STORM SURGES

2011 ◽  
Vol 1 (32) ◽  
pp. 13 ◽  
Author(s):  
Marie Naulin ◽  
Andreas Kortenhaus ◽  
Hocine Oumeraci
Keyword(s):  
Risk Analysis ◽  
Failure Probability ◽  
Storm Surges ◽  
Joint Research ◽  
Extreme Storm ◽  
Integrated Risk ◽  
Joint Research Project ◽  
Integrated Risk Analysis ◽  
Flood Defence ◽  
Failure Probabilities

Extreme storm surges can cause failures of flood defences resulting in severe flooding of the hinterland and catastrophic damages. In order to quantify the risk of flooding an integrated risk analysis is being performed wherein one task is the determination of failure probabilities of flood defences. In this paper the failure probability calculations of flood defence structures and systems under the loading of extreme storm surges are reported. Moreover, the analysis of the breach and breach development is briefly introduced. Preliminary results of the failure probabilities and the breach modelling are presented using the example of the estuarine urban area of Hamburg, Germany. These results are put in context of an integrated risk analysis approach for extreme storm surges which is applied within an ongoing German joint research project.

scholarly journals INTEGRATED FLOOD RISK ANALYSIS FOR EXTREME STORM SURGES (XTREMRISK)

2011 ◽  
Vol 1 (32) ◽  
pp. 9 ◽  
Author(s):  
Andreas Burzel ◽  
Dilani R. Dassanayake ◽  
Marie Naulin ◽  
Andreas Kortenhaus ◽  
Hocine Oumeraci ◽  
...  
Keyword(s):  
Risk Analysis ◽  
Flood Risk ◽  
Risk Mitigation ◽  
Storm Surges ◽  
Mitigation Measures ◽  
Joint Research ◽  
Extreme Storm ◽  
Joint Research Project ◽  
Flood Risk Analysis ◽  
First Results

Extreme storm surges have frequently led to major damages also along the German coastline. The joint research project 'XtremRisK' was initiated to improve the understanding of risk-related issues due to extreme storm surges and to quantify the flood risk for two pilot sites at the open coast and in an estuarine area under present and future climate scenarios. In this context, an integrated flood risk analysis is performed based on the source-pathway-receptor concept under consideration of possible tangible and intangible losses. This paper describes the structure of the project, the methodology of the subprojects, and first results. Moreover, integration approaches are discussed. The results of 'XtremRisK' will be used to propose flood risk mitigation measures for the prospective end-users.

scholarly journals Development of fragility curves for railway ballast and embankment scour due to overtopping flood flow

2016 ◽  
Author(s):  
Ryota Tsubaki ◽  
Koji Ichii ◽  
Jeremy D. Bricker ◽  
Yoshihisa Kawahara
Keyword(s):  
Spatial Distribution ◽  
Failure Probability ◽  
Fragility Curves ◽  
Railway Track ◽  
Single Track ◽  
Hydraulic Analysis ◽  
Railway Ballast ◽  
Log Normal ◽  
Flood Flow

Abstract. Fragility curves evaluating risk of railway track ballast and embankment fill scour were developed. To develop fragility curves, two well-documented single-track railway washouts during two recent floods in Japan were investigated. Type of damage to the railway was categorized into no damage, ballast scour, and embankment scour, in order of damage severity. Railway overtopping surcharge for each event was estimated via hydrologic and hydraulic analysis. Normal and log-normal fragility curves were developed based on failure probability derived from field records. A combined ballast and embankment scour model was validated by comparing the spatial distribution of railway scour with the field damage record.

FORWARD APPORTIONMENT OF CENSORED COUNTS FOR DISCRETE NONPARAMETRIC MAXIMUM LIKELIHOOD ESTIMATION OF FAILURE PROBABILITIES

2009 ◽  
Vol 16 (03) ◽  
pp. 213-234
Author(s):  
MINNIE H. PATEL ◽  
H.-S. JACOB TSAO
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Estimation ◽  
Closed Form ◽  
Failure Probability ◽  
Likelihood Estimation ◽  
Lifetime Distribution ◽  
Nonparametric Maximum Likelihood ◽  
Kaplan Meier ◽  
Probability Estimates ◽  
Failure Probabilities

Empirical cumulative lifetime distribution function is often required for selecting lifetime distribution. When some test items are censored from testing before failure, this function needs to be estimated, often via the approach of discrete nonparametric maximum likelihood estimation (DN-MLE). In this approach, this empirical function is expressed as a discrete set of failure-probability estimates. Kaplan and Meier used this approach and obtained a product-limit estimate for the survivor function, in terms exclusively of the hazard probabilities, and the equivalent failure-probability estimates. They cleverly expressed the likelihood function as the product of terms each of which involves only one hazard probability ease of derivation, but the estimates for failure probabilities are complex functions of hazard probabilities. Because there are no closed-form expressions for the failure probabilities, the estimates have been calculated numerically. More importantly, it has been difficult to study the behavior of the failure probability estimates, e.g., the standard errors, particularly when the sample size is not very large. This paper first derives closed-form expressions for the failure probabilities. For the special case of no censoring, the DN-MLE estimates for the failure probabilities are in closed forms and have an obvious, intuitive interpretation. However, the Kaplan–Meier failure-probability estimates for cases involving censored data defy interpretation and intuition. This paper then develops a simple algorithm that not only produces these estimates but also provides a clear, intuitive justification for the estimates. We prove that the algorithm indeed produces the DN-MLE estimates and demonstrate numerically their equivalence to the Kaplan–Meier-based estimates. We also provide an alternative algorithm.

Calculation of fragility curves for flood defence assets

2008 ◽  
pp. 567-573 ◽  
Author(s):  
J van der Meer ◽  
W ter Horst ◽  
E van Velzen
Keyword(s):  
Fragility Curves ◽  
Flood Defence

scholarly journals An advanced method for flood risk analysis in river deltas, applied to societal flood fatality risks in the Netherlands

2014 ◽  
Vol 2 (2) ◽  
pp. 1637-1670 ◽  
Author(s):  
K. M. de Bruijn ◽  
F. L. M. Diermanse ◽  
J. V. L. Beckers
Keyword(s):  
Risk Analysis ◽  
Flood Risk ◽  
Hydrodynamic Interaction ◽  
Storm Surges ◽  
Water Levels ◽  
Analysis Framework ◽  
Flood Risks ◽  
River Deltas ◽  
River Flood ◽  
Flood Risk Analysis

Abstract. This paper discusses the new method developed to analyse flood risks in river deltas. Risk analysis of river deltas is complex, because both storm surges and river discharges may cause flooding and since the effect of upstream breaches on downstream water levels and flood risks must be taken into account. A Monte Carlo based flood risk analysis framework for policy making was developed, which considers both storm surges and river flood waves and includes hydrodynamic interaction effects on flood risks. It was applied to analyse societal flood fatality risks (the probability of events with more than N fatalities) in the Rhine–Meuse delta.

Integrated flood risk analysis for extreme storm surges at open coasts and in estuaries

2012 ◽  
Author(s):  
H Oumeraci ◽  
A Kortenhaus ◽  
A Burzel ◽  
M Naulin ◽  
D Dassanayake ◽  
...  
Keyword(s):  
Risk Analysis ◽  
Flood Risk ◽  
Storm Surges ◽  
Extreme Storm ◽  
Flood Risk Analysis

A Further Minor Step—Minority-Related (D)eve(lopme)nts within the European Institutions throughout 2014

2016 ◽  
Vol 13 (1) ◽  
pp. 300-318
Author(s):  
Kinga Gál ◽  
Kata Eplényi
Keyword(s):  
European Commission ◽  
Linguistic Diversity ◽  
National Minority ◽  
The European Union ◽  
European Languages ◽  
National Minorities ◽  
Language Groups ◽  
Regional Language ◽  
European Institutions ◽  
First Results

This article covers those minority-related developments, important events and “missing” steps of the eu Institutions, especially the ep and the European Commission, throughout the year of 2014 that relate to traditional national minorities, regional language groups, and national communities. The year 2014 cannot be separated from 2013, thus the study covers one and a half years and analyses—among others—issues such as the first results of the European Citizens Initiative, the adopted resolution on endangered European languages and linguistic diversity in the European Union, the successful re-establishment of the “Intergroup for Traditional Minorities, National Communities and Languages” and the challenges the European Commission faces in this field. The study provides an analytical evaluation of this period. Throughout 2013 and 2014 a few minor steps forward were made within the European institutions on the field related to national minority protection; however, none of these should be over- or underestimated.

Reliabilities of Consecutive-2 Graphs

1987 ◽  
Vol 1 (3) ◽  
pp. 293-298 ◽  
Author(s):  
D.Z. Du ◽  
F. K. Hwang
Keyword(s):  
Failure Probability ◽  
Linear Time ◽  
Time Algorithm ◽  
Polynomial Algorithms ◽  
Linear Time Algorithm ◽  
Linear Algorithms ◽  
Failure Probabilities

A consecutive-2 graph is a graph where each vertex is associated with a failure probability and the graph is considered failed if any two adjacent vertices both fail. Recently, the problem of computing reliability for general consecutive-2 graph was shown to be #P-complete while polynomial algorithms exist for trees. In this paper, we give a linear time algorithm for a class of graphs including forests and cycles.For a given set of failure probabilities qi, the assignment of qi to the vertices of a given graph is optimal if it maximizes the reliability of that graph. It is known that optimal assignments for trees require messy computations while linear algorithms exist for lines and stars. In this paper, we prove that the optimal reliability of any n−tree is bounded between those of an n−line and an n−star.

Failure Probability Analysis of Aged Piping Using Probabilistic Fracture Mechanics Methodology Considering Seismic Loads

2016 ◽  
Author(s):  
Yoshihito Yamaguchi ◽  
Jinya Katsuyama ◽  
Yinsheng Li
Keyword(s):  
Fracture Mechanics ◽  
Failure Probability ◽  
Power Plants ◽  
Fragility Curves ◽  
Safety Margin ◽  
Probability Analysis ◽  
Seismic Loads ◽  
Probabilistic Fracture Mechanics ◽  
Age Related ◽  
Piping Systems

Several nuclear power plants in Japan have been operating for more than 30 years and cracks due to age-related degradations have been detected in some piping systems during in-service inspections. Furthermore, several of them have experienced severe earthquakes in recent years. Therefore, failure probability analysis and fragility evaluation for piping systems, taking both age-related degradations and seismic loads into consideration, has become increasingly important for the structural integrity evaluation and the seismic probabilistic risk assessment. Probabilistic fracture mechanics (PFM) is recognized as a rational methodology for failure probability analysis and fragility evaluation of aged piping, because it can take the scatters and uncertainties of influence parameters into account. In our Japan Atomic Energy Agency (JAEA), a PFM analysis code PASCAL-SP was developed for aged piping considering age-related degradations. In this study, we improved PASCAL-SP for the fragility evaluation taking both age-related degradations and seismic loads into account. The details of the improvement of PASCAL-SP are explained and some example analysis results of failure probabilities, fragility curves and a preliminary investigation on seismic safety margin are presented in this paper.

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