Risk Analysis of Tunnel Water and Mud Inrush Using Interpretive Structural Modeling and Fault Tree

Water and mud inrush is a common geological hazard in tunnel construction. Risk analysis of tunnel water and mud inrush has always been an important subject. In order to avoid the geological hazard, this paper presents a risk analysis model of tunnel water and mud inrush. The model combines the interpretive structural modeling method (ISM) and fault tree analysis (FTA). Relying on the Qinyu tunnel in the Weiwu expressway project, water and mud inrush risk factors are obtained by using ISM. Fundamental risk factors include formation lithology, attitude of stratum, strata combination, topography and geomorphology, geological structure and weather. ISM core risk factors are used as FTA basic events. Fuzzy importance of FTA basic events is obtained by using fuzzy interval calculation. The results show that geological structure is the primary risk factor causing Qinyu tunnel water and mud inrush. The model achieves qualitative and quantitative analysis of tunnel water and mud inrush. It accurately determines the main factors affecting the tunnel water and mud inrush, which is conducive to accident prevention.

Benchmarking the failure assessment of perishable product supply chain using fault tree approach: insights from apple case study of India

PurposeThe purpose of this paper is to facilitate perishable product supply chain (PPSC) managers and practitioners to assess PPSC failure events. The paper proposed fault tree methodology for assessing failures associated with PPSC for evaluating the performance in terms of effective PPSC management adoption.Design/methodology/approachInitially, different failure events were identified from literature and semi-structured interviews from experts. Fault tree model was developed from the identified failure events. Probability of failure events was calculated using Poisson distribution based on the annual reports and interviews conducted from experts. Further, qualitative analysis – minimum cut sets (MCSs), structural importance coefficient (SIC) – and quantitative analysis – Birnbaum importance measure (BIM), criticality importance factor (CIF) and diagnosis importance factor (DIF) – were performed for ranking of failure events. In this study, fault tree development and analysis were conducted on apple supply chain to present the authenticity of this method for failure analysis.FindingsThe findings indicate that the failure events, given as failure at production and procurement (A2), that is, involvement of middleman (BE3), handling and packaging failure (BE4) and transportation failure (A3), hold the highest-ranking scores in analysis of PPSC using fault tree approach.Originality/valueThis research uses the modularization approach for evaluation of failure events of PPSC. This paper explores failures related to PPSC for efficient management initiatives in apple supply chain context. The paper also provides suggestion from managerial perspective with respect to each failure event.

Fault Tree-Based Root Cause Analysis Used to Study Mal-Operation of a Protective Relay in a Smart Grid

This chapter presents how root cause analysis based on fault tree technique can be used to study mal-operation of protective relay in a smart power grid. This approach is used to identify disturbances first and root cause of mal operation of protective relays which may lead to unnecessary tripping and hence to blackout. Once the critical root causes are identified, mitigation measures first such as blocking protection functions and digital filters may be used in view of increasing the reliability of the considered protection system. The proposed approach has many advantages as it allows obtaining an important quantitative figure (security). These permits to strongly strengthen the elements of the protecting system which are most likely appropriate to failure and hence the impact on the overall system's cost is significant. Another main advantage is that it takes into account the reliability of the software part of the system which is considered to have a significant contribution in the overall reliability of the protecting system.

Análise da confiabilidade humana em um laboratório de análises clínicas utilizando FMEA e FTA

A análise de confiabilidade humana surge como suporte para quantificar e qualificar as falhas relacionadas às pessoas na execução de processos. Este trabalho apresenta um estudo de caso com o objetivo analisar a confiabilidade humana nos processos de atendimento de clientes e coleta de material biológico em um laboratório de análises clínicas. A pesquisa constituiu-se das seguintes etapas: revisão da literatura sobre os conceitos de falhas humanas e métodos para análise dessas falhas; mapeamento dos processos a fim de caracterizar falhas, levantamento do quantitativo de falhas por tipo e processo; análise do risco das falhas por meio da aplicação do método FMEA (Failure Mode and Effect Analysis); análise das causas das falhas, com o suporte de FTA (Fault Tree Analysis); e conclusões acerca das análises realizadas durante a pesquisa. Os levantamentos e análises realizados permitiram categorizar as falhas entre erros e transgressões e priorizar ações para preveni-las. Constatou-se que a ocorrência dessas falhas pode ser reduzida, se a qualificação profissional dos funcionários for consolidada.

МОДЕЛИРОВАНИЕ СИСТЕМЫ УПРАВЛЕНИЯ ПРОЦЕССАМИ ЭКСТРЕННОГО РЕАГИРОВАНИЯ ПРИ ЧС И ПОЖАРАХ

Статья посвящена решению проблемы многоэтапного моделирования системы управления процессами экстренного реагирования при ЧС и пожарах с постепенным повышением детализации создаваемых моделей на основе метода дедукции. В работе обоснована актуальность решения данной проблемы, обусловленная необходимостью формализации процессов управления для обеспечения компьютерной поддержки процессов управления. Разработаны концептуальные и функциональные модели с последовательным уточнением и детализацией процессов. Разработано дерево ошибок на основе методологии анализа дерева отказов (Fault tree analysis, FTA) и системного подхода с многими состояниями системы (Multi-State System, MSS). Идентифицировано место системы управления в системе классификации социально-экономических систем (СЭС). Построенные модели предназначены для формализации процессов управления в условиях ЧС и пожаров с целью обеспечения возможности осуществления из информационно-аналитической поддержки.

Evaluation of the Main Causes of Diesel Engine Injector Failure using Fault Tree Analysis

This paper is based on the application of the root cause analysis principle of diesel engine injector failure in diesels Haditha station. The maintenance of the diesel engine injector contains many problems that lead to the injector stopping; several reasons lead to such Problems. Fault tree analysis (FTA) is one of the most widely used methods in the industrial sector to perform reliability analysis of complex engineering systems. A fault tree is a logical representation of the relationship of primary/basic events that lead to a given undesirable event (i.e., top event). This research aims to present the (FTA) technology and how to use it in analyzing the causes of problems that lead to the injector stop working, and how to calculate the probability of occurrence of such problems. Implementation of FTA based on the probabilities of the causes under the top event and canalization lead to the calculated probability value (0.80). The plant management can define a specific plan to reduce these problems, because failure of an important engine part (injector) with such a large value leads to long downtime hours compared to operating hours.