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In order to realistic study of fire accidents in tunnel, according to the uncertainty and fuzziness of accident, the model of fault tree is established for Nanjing Yangtze River Tunnel after Nanjing Yangtze River Bridge closed, and with the triangular fuzzy theory, the estimate of base event is obtained by scoring of the relevant professional, and the probable range of top event is calculated. In addition, the fuzzy importance is obtained by the median method of triangular fuzzy theory, to find the fuzzy importance of basic event. Then the fire prevention measures are proposed for Nanjing Yangtze River Tunnel. The results show that the possibility of uncontrolled fire is small in Nanjing Yangtze River Tunnel. Among them, fire rescue no arriving in time, no knowledge of fire extinguishing, vehicle collision on fire and auto-alarm failure are main factors leading to catastrophic fire. Thus, it is of great significance to strengthen the fire-fighting knowledge of personnel and the capacity of automatic fire-fighting for the tunnel itself, to reduce the occurrence of fire in tunnel.

Loading and unloading of containers from ship to the quay at the container terminal is a high risk activity that has high potential of creating accidents both to human as well as to property. The study is aimed to conduct safety assessment that can be used further for minimising work accidents at the port. Hazard Identification and Risk Assessment (HIRA) method is used to identify the type, cause, and effect of the potential risks based on the activity sequences. A risk matrix is arranged for obtaining the risk level. Root cause of the highest risk activity is investigated using Fault Tree Analysis (FTA) method. 5 potential risks are identified i.e. worker slips, trips or falls; truck struck by quay crane, worker struck by truck, worker struck by falling hatch cover or container, and worker trapped between containers. The root causes of potential accidents are human fault, equipment maintenance, and environment.

Deep mining, driven by the increasing need of the sustainable use of mineral resources, yields a chance to exploit untapped resources. Nevertheless, large depths remain challenging and complex environment, posing geotechnical risks such as stress driven damage. The violent damage mechanisms in deep mines are spalling and strainburst in their most severe forms. Real-time monitoring can not only assist in preventing a failure, but can also assist in post failure mitigations. It can help identify the possible systemic failure of adjacent areas and can therefore help in evacuating people and machinery from these areas. The long-term goal is to develop a real-time risk management concept for intelligent deep mines. The objective of this paper is to summarize the outcomes of I 2 Mine and DynaMine, formulate a risk concept suitable for real-time analysis and to produce a tangible measure of the risk levels. In this paper the Fault Tree – Event Tree methodology is proposed and an example is worked out using strainburst as an example risk case. The proposed methodology seems to work well and using a scenario with both property damage and ore loss, the risk expressed as financial consequences multiplied with probability drops from € 88,000 to € 11,000 corresponding to a - 80% reduction in risk. The financial consequences together with the associated risk level can be expressed visually using a modified FN graph with financial loss on x-axis and probability on the y-axis. The developed geotechnical risk management concept suits the need of semi-automated or fully automated risk management. It would fit well in the analysis stage of the raw data and would produce a stress state change, which could be used as input in the risk management chain for intelligent deep mines.

Nowadays, in order to prevent large-scale casualties and significant property losses in the society, strengthening the building fire safety of hotels has become one of the hottest topics explored by more and more experts and scholars. In accordance with the building fire system analysis of hotels, considering the whole process of the fire accident, the fault tree of building fire was established. The analysis of relationship between the primary and secondary factors was conducted from three parts, the minimal cut set, the minimal radius set and the importance of structure. There are three main reasons for building fires in hotels, involving the personnel's unsafe behavior, the failures of electrical equipment and wiring as well as the ignition of flammable and combustible substance. And the key measures for prevention of building fires including strengthening the management of daily fire safety, key positions and key personnel have been proposed, which can improve the safety and operational reliability of hotel buildings. The analysis shows that the fault tree analysis method can make a comprehensive exposition of various factors causing fire of hotel buildings and their logical relations, which also provides a reference for the improvement of the design and the construction of the safety technical measures in other fields.

Unexpected hard rubbing of the fan tip and case occurred during the reduced-scale high-bypass fan performance test which took place at a bypass compressor Test-Facility of an institute. A great deal of effort had been expended with regard to this event. Firstly, failure investigation was done by means of Fault Tree Analysis which was based on the on-site test failure records, test pieces dis-assembly check and Test-Facility check. Results indicate that the fault waspossibly caused by the combination effect of over-rated motor starting acceleration and insufficient value of the fan blade tip clearance and axial length of the case coatingin design. Then, failure reproduction,confirmation of reasons and mechanism analysis were done by simulating the spinner cone bolt deformation and simulating the rubbing of fan blades and case, in combination with the analysis of the characteristics of fan blade and the no-load test of motor starting.Finally, in order to solve the problem, several improvements were established, including modifying the motor speed limit parameters to reduce the starting acceleration, increasing the fan blade tip clearance and increasing the axial length of the case coating. These solutions were verified by test.

Railway track subgrade failure induced by climate related softening, may lead to unplanned maintenance costs and consequential and costly train delays. The softening process can be due to the presence of water in the upper parts of the track foundation due to inadequate drainage system or poorly maintained railway track drainage. In order to better make use of scarce resources and plan railway track and associated drainage maintenance rationally it would be helpful to better understand and quantify the relationships between the causes of poor subgrade and the railway track drainage system. The understanding of railway track drainage associated failure can be further used to infer engineering knowledge into railway performance models and associated risk analysis methodologies. To this end, this paper describes the development of a fault tree analysis approach which considers the failure mode(s) for railway track subgrade. The fault chart has been developed in two stages, in the first stage, failure mechanisms are diagnosed utilizing a cause-effect diagram, and in the second stage a fault tree analysis (FTA) is performed.

One approach based on AC20-128A is presented in order to assess the risk caused by uncontained engine rotor failure (UERF). In this approach, the risk assessment procedure includes hazard identification and hazard quantification. In the step of hazard identification, the catastrophic functional hazards, derived from the functional hazard analysis (FHA) results for the airplane, are used as the top events to construct the fault trees. The minimal cut sets (MSCs) of the fault trees are the hazards to be identified exactly. In the step of hazard quantification, the probability of one hazard triggered by some uncontained debris is evaluated. After the probabilities of all the identified hazards are quantified, the risk assessment of the airplane is completed. And the assessment result is compared with the design specifications to show compliance with the safety design. A small example is introduced to illustrate the rationality and accuracy of the aforementioned method.

City fire risk analysis is a very important basis for scientifically and effectively planning and deploying urban fire protection and formulating its related regulations. It also can guarantee and facilitate the coordinated development of city's economic construction and social economy. Combining the city's development characteristic of China and the fire control safety management state, the thesis based on fire control safety engineering and systematic safety engineering theory and combine, has set up the fire risk fault tree of city area. Applying the method of the fuzzy important degree sorted the basic incident of the fault tree and did a fuzzy graduation on the factors of caused fire. The order and grade of fuzzy probability has shown that the main factors of limiting fire risk are the city area overall arrangement, the moved fire control strength and the personnel quality, which is in conformity with the main reason of the city fire of our country taken place over the years. For this reason, in order to limit the city fire risk fundamentally, we must manage the above three important factors strictly, which has a very positive significance for city fire safety management of China.

The roof fall accident is one of the most frequent accidents in the coal mine and its frequency is ranked the first in various coal mine accidents. Hazard identification is a common method to prevent accidents. On the basis of predecessors’ research, the concepts and identification indicators of the hazard sources in coal mine roof fall accident are defined initially. Hazard source of roof fall accident is analyzed quantitatively by the method which is combined triangular fuzzy theory and traditional fault tree to avoid the structural problems of the fault tree itself. Large area of empty-support is the greatest hazard sources in roof fall accident by the research.

Historically, fault trees are extensively used in Probabilistic Safety Assessment (PSA) to model and evaluate the probability and consequence of failures of complex engineering systems, such as nuclear power plants. Scenarios of hypothetical accidents resulting in severe core damage can be developed. Petri net is another modeling technique that offers many advantages when comparing with fault trees, such as is ability to represent the time sequence of the events along with their duration. In this research, Petri net theory is extended to model system failures. The transformations required to model logic gates by Petri nets are explored and examples provided. Methods for qualitative analysis for Petri nets are presented. The application of Petri net in the airlock system of a Canada Deuterium Uranium (CANDU) reactor is explored. It is further demonstrated that Petri net can be used in both coherent and non-coherent systems.

The paper dedicates to analysis of the main reasons of the mine gas explosion accident through the statistics of mine gas explosion accidents at home and abroad. The inner logic relationship between accidents and the causes of accidents is explored by using fault tree analysis method. The relationship between the safety input and accident occurrence frequency is discussed, and the function relationship between which is established with GongBo curve. On the basis of settled safety investment, using the influence of basic event on top accident's occurrence probability, the safety input optimization allocation model is established for the goal of making the accident occurrence probability minimum, which can be solved by using Lingo software based on historical data.

The safety design is very important to civil aircraft. In order to verify the civil aircraft design whether meet the requirement of airworthiness regulation about the hazards to an airplane in the event of uncontained turbine engine rotor failure, which require the design measures to minimize the hazards in the case of uncontained turbine engine rotor failure. Airworthiness compliance verification method is presented in this paper .Firstly, in the cause of uncontained rotor fragments bursting out, the hazards validation method is proposed based on the results of airplane level functional hazard analysis (FHA) and fault tree analysis (FTA) in this paper. Secondly, airworthiness compliance verification procedure is developed. Thirdly, quantitative assessment model of hazards caused is proposed and calculated. Finally, an example show the whole airworthiness compliance verification procedure include hazards validation, quantitative calculation and airworthiness compliance verdict Results show that the hazard combinations resulting in multiple systems failure can be identified, thus providing more sufficient basis for airplane design improvement to minimize the hazards caused by uncontained engine rotor failure.

Based on FTA of safety-system engineering and analysis of risk or hazard factors of technological process and materials, it is determined of the fault tree factor table of crude oil gathering-transport combination station and established of the fire and explosion fault tree. By means of Boolean algebra simplification, the minimum path sets of the system are achieved. Then the occurrence probability of the fault tree top event is given together with the three importance-degree analysis of the basic event. Through the fault tree analysis, the paper discusses qualitatively and quantitatively the main factors of fire and explosion in combination station, and some corresponding improvement measures are proposed. The analysis result can provide theoretical direction for design, construction, management and maintenance of crude oil gathering-transport combination station.

Over the last decade, Nuclear energy has become one of important energy. Nuclear power systems become more complex and traditional safety methods are hard to be applied. This paper presents a novel approach for nuclear power plant safety analysis which called Bayesian Networks(BN). The BN model is constructed based on the combination of Failure Mode, Effect Analysis (FMEA) and Fault Trees Analysis(FTA). The probability of the model’s root nodes is estimated by Bayesian estimation method and Monte Carlo simulation. Bidirectional inference and sensitivity analysis of the model is also researched. At last, we use a case study to show the method’s advantages compared with traditional methods in nuclear power plant safety analysis.

Since multiple state events could not be described and accident probability could not be calculated by fault tree quantitatively for safety assessment, applications of Bayesian network (BN) in safety and reliability fields for the past few years were introduced and basic principle and inference algorithm of Bayesian network were presented. A Bayesian network was developed to model open press electric shock accident as a result of charged press enclosure. The multi-state nodes of the network were illustrated and accident probability was computed finally. The results show that Residual Current Operated Circuit-Breaker with Integral Overcurrent Protection (RCBO) installation can reduce accidents probability of phase-voltage and under-phase-voltage electric shock sharply for open press working in T - T system of low voltage power supply system. In a word, Bayesian network can model system which contains multiple state events, furthermore, accidents probability of that system can be computed correctly, in addition, it offers a comparative tool for various safety design of machine system to guarantee machine inherent safety.

This paper thoroughly studied the methodology of CCMR analysis, clarified the relationship between CCMR analysis, specific risk analysis, and MSG-3 analysis through discussion of a real certification program. Provided a lessons learned case and reference to other aircraft type design and certification.

August 12, 2011, a locomotive runaway has happened on the local railway named Xihe railway of a certain city, it led to a death of an older person and serious damage of four automobiles. The causing factors of the runaway accident have been comprehensively analyzed, which respectively include four aspects: human, machine, environment and management. By using the principle of fault tree analysis (FTA), the locomotive runaway accident fault tree has been set up after the accident investigation. Based on the corresponding formula, the authors have calculated the structure importance coefficient of each basic event. By analyzing the causation of the events, the minimal path sets have been obtained, and the order of the structure importance has also been obtained. Through the above analysis, the reasons of this accident have been analyzed systematically and the corresponding safety countermeasures have been proposed. The thesis can provide reference for prevention of similar accidents.

With the increasing scale and complexity of modern systems, traditional safety analysis methods such as FTA, FMEA seem inconvenient to use. Automated safety analysis based on formal models has become popular. In this paper, we took the Altarica data-flow language as the research object, and specified how to extract failure logic relations from Altarica component models and system models to generate fault trees (FTs), and proved its validity through instance verification. Fault tree generation method proposed in this paper would provide a basis for the development of automated safety analysis tools based on Altarica.

The research objects of conventional risk assessment methods such as fault tree, event tree, etc., are always considered as two ultimate states, one is the complete failure and the other is the perfect state. In this condition, the effect of partial system failure on system performance is not taken into account, which leads to a big difference between calculation results by risk assessment model and actual situation. Multi-state Markov model has been proven to be a versatile tool for modeling multi-state system. It has been effectively used to interpret the degradation relationship between the perfect state and complete failure in the real world. Unfortunately, multi-state Markov model suffers state space explosion, where the generating states grows exponentially with the number of components comprised in the system. For these issues, a multi-state Bayesian network method and its corresponding algorithms for risk assessment were proposed in this paper. In addition, the availability and accuracy of the proposed method were validated by an application example of the oil gathering and transferring system. The results showed that multi-state Bayesian network method was effective to cope with multi-state system by its powerful ability of bidirectional reasoning and probability updating. Compared with multi-state Markov model, the multi-state Bayesian network method is simplified and its computational efficiency is improved. Furthermore, this method could ensure the credibility of risk assessment results as far as possible by taking new information into account and updating the prior beliefs about the accident.

Safety analysis is an important method of compliance demonstration for airworthiness regulation. In this paper, the application of Markov analysis in system safety assessment is studied, and the common method of Markov analysis for system safety assessment is given. A failure state of flight control system is modeled and analyzed by Markov analysis and fault tree analysis respectively, and the results show that Markov method has a higher accuracy of quantitative analysis of the sequence related events. This method also overcomes the shortcomings of the static analysis features of the fault tree analysis.

Cotton logistics warehouses have increased unceasingly along with the development of society. Firstly, referring to a hundred cotton logistics warehouse fires, based on the relevant provisions of the cotton logistics warehouse, and fire safety issues are summarized in this paper. Secondly, according to the physical and chemical characteristics of cotton, the fire risk of cotton logistics warehouse is analyzed, and the fire hazard sources are identified. Thirdly, Event and Fault Tree Analysis (EFTA) is used to explore the disaster mechanism of cotton logistics warehouses to obtain disaster reducing factors. In the end, based on the above analyses, a set of fire prevention measures against the cotton logistics warehouse are put forward. The result shows that the probability of moisture absorption and heat release is the highest of all causes of smoldering fire, so it is essential to control the temperature below 343K and the humidity below 70% when keeping in storage. Lacking of spaces between shelves is an important factor leading to the spread of fire. In the process of fire fighting, water supply is the key factor, so appropriate water storage facility for fire-fighting is necessary before the establishment of the cotton logistics warehouse.

Bridge erecting machine has been widely used nowadays with its efficiency, while just as a coin has two sides, it also brings problem. If a rollover happens, it will lead to equipment damage, casualties or other disastrous accidents. How could technicians take measures to prevent accidents as efficiently as possible? Question remains unsaved. Based on the analysis of “10.26” bridge erecting machine tipping accident, this paper gives a qualitative analysis on the accident by using fault tree analysis. Firstly, fault tree diagram for the bridge erecting machine tipping, namely the causal and generalization relation between events is formulated. All the basic events that influence the way and the degree of the accident are identified, and these can be ascribed to the following three aspects: manufacturing defect, personnel operating error and management oversight. In terms of management oversight, the responsibility of construction unit, safety supervision department and supervision unit are of great importance. Secondly, combining the minimal path set with the structure importance, we conduct a qualitative analysis on the personnel casualties resulted from the accident, thus seek critical approaches to accident prevention. Finally corresponding safety control measures are put forward. It is noteworthy that the approach can be applied in the similar accidents entirely.