Sequential Propagation of Seismic Fragility across Interdependent Lifeline Systems

2011 ◽  
Vol 27 (1) ◽  
pp. 23-43 ◽  
Author(s):  
Isaac Hernandez-Fajardo ◽  
Leonardo Dueñas-Osorio
Keyword(s):  
Network Performance ◽  
Fragility Curves ◽  
Mitigation Strategies ◽  
System Management ◽  
Seismic Action ◽  
Water Network ◽  
Service Networks ◽  
Lifeline System ◽  
Failure Propagation ◽  
Lifeline Systems

Realistic models of service networks must consider the evolution of interactions with external systems to evaluate emergent response effects on individual network performance. This paper introduces a new dynamic methodology for the assessment of systemic fragility propagation across interdependent networks subjected to seismic action that improves existing static methodologies. Interdependencies are discrete, unidirectional relationships between elements of distinct networks, which are able to influence response evolution from transient to steady-state stages. Comparisons of systemic fragility curves results for isolated and interdependent power and water networks display the importance of interdependence strength and density properties. For the test water network, inter-systemic failure propagation increases its connectivity loss by up to 24%, while high interdependence strengths make the median fragility rise up to 56.2%. In contrast, reductions of interdependence density improve the median water fragility up to 81.7%. Insights obtained from this model, and its associated sequential fragility algorithm, reveal complex coupling patterns and interdependence-based mitigation strategies that are essential for lifeline system management.

SEISMIC RISK AND RESILIENCE ASSESSMENT OF INDUSTRIAL FACILITIES: CASE STUDY ON A BLACK CARBON PLANT

2020 ◽  
Author(s):  
George Karagiannakis
Keyword(s):  
Seismic Risk ◽  
Numerical Models ◽  
Fragility Curves ◽  
Human Life ◽  
Mitigation Strategies ◽  
Economic Losses ◽  
Risk And Resilience ◽  
Industrial Plants ◽  
Plant Equipment

This paper deals with state of the art risk and resilience calculations for industrial plants. Resilience is a top priority issue on the agenda of societies due to climate change and the all-time demand for human life safety and financial robustness. Industrial plants are highly complex systems containing a considerable number of equipment such as steel storage tanks, pipe rack-piping systems, and other installations. Loss Of Containment (LOC) scenarios triggered by past earthquakes due to failure on critical components were followed by severe repercussions on the community, long recovery times and great economic losses. Hence, facility planners and emergency managers should be aware of possible seismic damages and should have already established recovery plans to maximize the resilience and minimize the losses. Seismic risk assessment is the first step of resilience calculations, as it establishes possible damage scenarios. In order to have an accurate risk analysis, the plant equipment vulnerability must be assessed; this is made feasible either from fragility databases in the literature that refer to customized equipment or through numerical calculations. Two different approaches to fragility assessment will be discussed in this paper: (i) code-based Fragility Curves (FCs); and (ii) fragility curves based on numerical models. A carbon black process plant is used as a case study in order to display the influence of various fragility curve realizations taking their effects on risk and resilience calculations into account. Additionally, a new way of representing the total resilience of industrial installations is proposed. More precisely, all possible scenarios will be endowed with their weighted recovery curves (according to their probability of occurrence) and summed together. The result is a concise graph that can help stakeholders to identify critical plant equipment and make decisions on seismic mitigation strategies for plant safety and efficiency. Finally, possible mitigation strategies, like structural health monitoring and metamaterial-based seismic shields are addressed, in order to show how future developments may enhance plant resilience. The work presented hereafter represents a highly condensed application of the research done during the XP-RESILIENCE project, while more detailed information is available on the project website https://r.unitn.it/en/dicam/xp-resilience.

scholarly journals Reliability and protection in distribution power system considering customer-based indices

2021 ◽  
Vol 39 (4) ◽  
pp. 1198-1205
Author(s):  
J.N. Nweke ◽  
A.G. Gusau ◽  
L.M. Isah
Keyword(s):  
Power Supply ◽  
System Reliability ◽  
Distribution System ◽  
Network Performance ◽  
Test System ◽  
Mitigation Strategies ◽  
Reliability Indices ◽  
Electric Power Supply ◽  
Utility Company ◽  
Distribution System Reliability

A stable and reliable electric power supply system is a pre-requisite for the technological and economic growth of any nation. Nigeria's power supply has been experiencing incessant power interruptions caused by a failure in the distribution system. This paper developed a system planning approach as part of the key mitigation strategies for improved reliability and protection of the distribution network. The developed algorithm is tested using 33kV feeder supplying electricity to Kaura-Namoda, Zamfara State,  Nigeria. A customer-based reliability index was used as a tool to evaluate the reliability assessment of the feeder test system. The result showed that alternative 3 gives better results in terms of improvement of the system average interruption duration index (SAIDI), which in turn gives the minimum interrupted energy. Also, it is found that a greater number of sectionalizing switches do not give better results. It is very important to place the sectionalizing switches at a strategic location. If it is located at such points that will facilitate to sectionalize the faulty sections faster and to make the supply available to the unfaulty part of the network. Hence the utility company should apply this mitigation algorithm for system reliability improvement, depending on their needs and requirements. Thus, utilities can optimize network performance and better serve customers by adopting mitigation strategies in addressing trouble-prone areas to achieve a stable and reliable supply Keywords: distribution system; reliability; reliability indices; system performance evaluation; protection system; mitigation algorithms and sectionalizing switches 

scholarly journals Stochastic Vulnerability Assessment of Masonry Structures: Concepts, Modeling and Restoration Aspects

2019 ◽  
Vol 9 (2) ◽  
pp. 243 ◽  
Author(s):  
Panagiotis G. Asteris ◽  
Antonia Moropoulou ◽  
Athanasia D. Skentou ◽  
Maria Apostolopoulou ◽  
Amin Mohebkhah ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Methodological Approach ◽  
Seismic Action ◽  
Masonry Structures ◽  
Structural System ◽  
Brittle Behavior ◽  
Masonry Material ◽  
Probabilistic Nature

A methodology aiming to predict the vulnerability of masonry structures under seismic action is presented herein. Masonry structures, among which many are cultural heritage assets, present high vulnerability under earthquake. Reliable simulations of their response to seismic stresses are exceedingly difficult because of the complexity of the structural system and the anisotropic and brittle behavior of the masonry materials. Furthermore, the majority of the parameters involved in the problem such as the masonry material mechanical characteristics and earthquake loading characteristics have a stochastic-probabilistic nature. Within this framework, a detailed analytical methodological approach for assessing the seismic vulnerability of masonry historical and monumental structures is presented, taking into account the probabilistic nature of the input parameters by means of analytically determining fragility curves. The emerged methodology is presented in detail through application on theoretical and built cultural heritage real masonry structures.

scholarly journals Organizing for inter-organizational learning in service networks

2019 ◽  
Vol 26 (3) ◽  
pp. 276-288 ◽  
Author(s):  
Jean-Paul Peronard ◽  
Jacob Brix
Keyword(s):  
Organizational Learning ◽  
Design Methodology ◽  
Network Performance ◽  
Allocation Of Resources ◽  
Learning Context ◽  
Service Networks ◽  
Service Network ◽  
Content Type ◽  
Learning Challenges ◽  
Practical Implications

Purpose The purpose of this study is to consolidate existing research on ‘service networks’ and to frame this literature as a new ‘context for learning’. Research from inter-organizational learning is used to qualify this consolidation and advances from inter-organizational learning are used to operationalize how service network actors in this new context can organize for inter-organizational learning to create more value for themselves and their customers. Design/methodology/approach By conceptualizing the learning context of a service network and the interrelated dimensions, an overview of the learning challenges for improved service performance is provided. Findings Inspired by the service triangle, the proposed framework highlights the learning challenges among two or more actors and the knowledge and skills needed for them to organize the service network. To build a collaboration characterized by trust, behaviors associated with transparency and receptivity are argued to be imperative. Practical implications The framework can increase the opportunities for inter-organizational learning in a service network. Knowing the learning context and the challenges associated with this learning allows for a more accurate intervention and allocation of resources to improve service network performance. Originality/value The novelty lies in the consolidation of the literature of service networks and the extension of the literature on inter-organizational learning hereto.

Damage Variation in Highway Bridge Piers for Rehabilitation with Different Reinforced Options

2013 ◽  
Vol 569-570 ◽  
pp. 254-261
Author(s):  
Consuelo M. Gómez-Soberón ◽  
Bertha Olmos-Navarrete ◽  
Manuel Jara-Díaz ◽  
José Manuel Jara-Guerrero
Keyword(s):  
Fragility Curves ◽  
Damage Index ◽  
Bridge Piers ◽  
Highway Bridge ◽  
Seismic Action ◽  
Damage Level ◽  
Degree Of Protection ◽  
Seismic Scenarios ◽  
Earthquake Zone ◽  
High Degree

Bridges are considered as vital components that require a high degree of protection to guarantee their functionality, even after significant earthquakes. So, the damage evaluation of current conditions of these structures is considered a necessary tool for inspection, maintenance and rehabilitation. Seismic fragility curves of a common highway bridge structure, with simple-supported girders, for different seismic scenarios, are evaluated in this paper. The selected bridge is a RC system with rectangular piers, forming a frame substructure; the bridge piers reinforcement is designed using steel jackets. Damage fragility curves are again evaluated for the reinforced system and compared with the initial condition; for that, a non-linear analyses with Ruaumoko program are accomplished, using a Takeda constitutive model and the damage index proposed by Parket al. As an external seismic action, artificial accelerograms are obtained based on signals registered in the most hazardous earthquake zone of Mexico. The probability changes of a certain damage level are verified for the obtained results.

A Model-Based Failure Identification and Propagation Framework for Conceptual Design of Complex Systems

2012 ◽  
Author(s):  
Hoda Mehrpouyan ◽  
David C. Jensen ◽  
Christopher Hoyle ◽  
Irem Y. Tumer ◽  
Tolga Kurtoglu
Keyword(s):  
System Architecture ◽  
Early Identification ◽  
Mitigation Strategies ◽  
Functional Requirements ◽  
Environmental Disturbances ◽  
Safety Issues ◽  
Model Based ◽  
Potential Safety ◽  
Failure Propagation ◽  
Failure Identification

In this paper, a model-based failure identification and propagation (MFIP) framework is introduced for early identification of potential safety issues caused by environmental disturbances and subsystem failures within a complex avionic system. The MFIP framework maps hazards and vulnerability modes to specific components in the system and analyzes failure propagation paths. Block definition diagrams (BDD) are used to represent system functional requirements in the form of demonstrating the relationships between various requirements, their associations, generalizations, as well as dependencies. These concept models help to identify hazardous factors and the relationships through which their detrimental effects are transferred through-out the proposed system architecture. As such, the approach provides the opportunity to reduce costs associated with redesign and provide important information on design viability. Using this technique, designers can examine the impacts of environmental and subsystem risks on the overall system during the early stages of design and develop hazard mitigation strategies.

scholarly journals Relationships between empirical damage and direct/indirect costs for the assessment of seismic loss scenarios

2021 ◽  
Author(s):  
Marco Di Ludovico ◽  
Giuseppina De Martino ◽  
Andrea Prota ◽  
Gaetano Manfredi ◽  
Mauro Dolce
Keyword(s):  
Empirical Data ◽  
Residential Buildings ◽  
Fragility Curves ◽  
Unit Cost ◽  
Indirect Costs ◽  
Mitigation Strategies ◽  
Damage State ◽  
Reconstruction Process ◽  
2009 L’Aquila Earthquake ◽  
Damage States

AbstractThe definition of relationships between damage and losses is a crucial aspect for the prediction of seismic effects and the development of reliable models to define risk maps, loss scenarios and mitigation strategies. The paper focuses on the analysis of post-earthquake empirical data to define relationships between buildings’ damage expressed as usability rating or as global damage state and the associated costs for repair (i.e. direct costs) or for population assistance (i.e. a part of total indirect costs). The analysis refers to the data collected on residential buildings damaged by 2009 L'Aquila earthquake. For different usability rating or damage states, the paper presents the costs expressed in terms of percentage with respect to the reference unit cost of a new building (%Cr and %Ca for repair and population assistance costs, respectively). In particular, the costs analysis refers to undamaged, lightly or severely damaged buildings classified according to usability rating (i.e. A, B-C or E according to Italian classification) or to five different global Damage States (DSs). DSs comply with European Macroseismic Scale (EMS-98) and derive from literature available matrices properly defined to convert empirical damage to structural and non-structural components into building global damage. The %Cr probability density functions and relevant statistics derive from the analysis of actual data of post-earthquake reconstruction process, while, to determine those related to %Ca, a deep analysis of population assistance types, person/month assistance cost for each assistance form, and a methodology to associate such costs to each building are herein presented and discussed. Finally, the paper presents a relationship calibrated on empirical data to directly correlate repair costs on a building with assistance costs to their occupants. The relationships between empirical damage and direct and indirect costs herein presented are of paramount importance because they allow reliable loss scenarios to be defined by simply using literature fragility curves (defined according to empirical or mechanical approaches) aimed at evaluating the probability of exceeding different usability rating or damage states of existing buildings.

Optimization-Based Probabilistic Consequence Scenario Construction for Lifeline Systems

2014 ◽  
Vol 30 (4) ◽  
pp. 1531-1551 ◽  
Author(s):  
Jared Gearhart ◽  
Nathanael Brown ◽  
Dean Jones ◽  
Linda Nozick ◽  
Natalia Romero ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Joint Distribution ◽  
Optimization Method ◽  
Seismic Zone ◽  
Realistic Case ◽  
Lifeline System ◽  
Highway Network ◽  
Lifeline Systems

The construction of a suite of consequence scenarios that is consistent with the joint distribution of damage to a lifeline system is critical to properly estimating regional loss after an earthquake. This paper describes an optimization method that identifies a suite of consequence scenarios that can be used in regional loss estimation for lifeline systems when computational demands are of concern, and it is important to capture the spatial correlation associated with individual events. This method is applied to a realistic case study focused on the highway network in Memphis, Tennessee, within the New Madrid Seismic Zone. This case study illustrates that significantly fewer consequence scenarios are needed with this method than would be required using Monte Carlo simulation.

scholarly journals Quantification of Lifeline System Interdependencies after the 27 February 2010 Mw 8.8 Offshore Maule, Chile, Earthquake

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 581-603 ◽  
Author(s):  
Leonardo Dueñas-Osorio ◽  
Alexis Kwasinski
Keyword(s):  
Power Systems ◽  
Prediction Models ◽  
Lifeline System ◽  
Disaster Data ◽  
Chile Earthquake ◽  
Cross Correlations ◽  
Coupling Strengths ◽  
Lag Times ◽  
Lifeline Systems ◽  
Chilean Earthquake

Data on lifeline system service restoration is seldom exploited for the calibration of performance prediction models or for response comparisons across systems and events. This study explores utility restoration curves after the 2010 Chilean earthquake through a time series method to quantify coupling strengths across lifeline systems. When consistent with field information, cross-correlations from restoration curves without significant lag times quantify operational interdependence, whereas those with significant lags reveal logistical interdependence. Synthesized coupling strengths are also proposed to incorporate cross-correlations and lag times at once. In the Chilean earthquake, coupling across fixed and mobile phones was the strongest per region followed by coupling within and across telecommunication and power systems in adjacent regions. Unapparent couplings were also revealed among telecommunication and power systems with water networks. The proposed methodology can steer new protocols for post-disaster data collection, including anecdotal information to evaluate causality, and inform infrastructure interdependence effect prediction models.

scholarly journals Dual-use value of network partitioning for water system management and protection from malicious contamination

2014 ◽  
Vol 17 (3) ◽  
pp. 361-376 ◽  
Author(s):  
Armando Di Nardo ◽  
Michele Di Natale ◽  
Dino Musmarra ◽  
Giovanni Francesco Santonastaso ◽  
Velitchko Tzatchkov ◽  
...  
Keyword(s):  
Water System ◽  
Water Systems ◽  
System Management ◽  
Network Partitioning ◽  
Water Network ◽  
Dual Use ◽  
Malicious Attack ◽  
Remote Control System ◽  
Large Water ◽  
Water Network Partitioning

This paper considers the introduction of a contaminant into a water supply system using a backflow attack. The recent development of techniques for water network sectorization, aimed at improving the management of water systems, is also an efficient way to protect networks from intentional contamination and to reduce the risk of the dangerous effects of network contamination. Users can be significantly protected by isolated district meter areas (i-DMAs) in the water network and the closing of the gate valves by a remote control system to implement such i-DMAs in cases of malicious attacks. This study investigates the effects of different approaches for water network partitioning and sectorization to protect networks using a technique for designing i-DMAs that is compatible with hydraulic performance and that is based on graph theory and heuristic optimization. For this analysis, the introduction of cyanide through a backflow attack was assumed. The methodology was tested on a large water network in Mexico and displayed good protection from a malicious attack.

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