A fuzzy Bayesian belief network for safety assessment of oil and gas pipelines

Safety assessment of oil and gas (O&G) pipelines is necessary to prevent unwanted events that may cause catastrophic accidents and heavy financial losses. This study develops a safety assessment model for O&G pipeline failure by incorporating fuzzy logic into Bayesian belief network. Proposed fuzzy Bayesian belief network (FBBN) model explicitly represents dependencies of events, updating probabilities and representation of uncertain knowledge (such as randomness, vagueness and ignorance). The study highlights the utility of FBBN in safety analysis of O&G pipeline because of its flexible structure, allowing it to fit a wide variety of accident scenarios. The sensitivity analysis of the proposed model indicates that construction defect, overload, mechanical damage, bad installation and quality of worker are the most significant causes for the O&G pipeline failures. The research results can help owners of transmission and distribution pipeline companies and professionals to prepare preventive safety measures and allocate proper resources.     

城市燃气管道风险评价研究

概述了风险评价的定义以及国内外燃气管道风险评价的研究现状,针对某市燃气管道,采用基于层次分析法的模糊综合评价方法对燃气管道潜在风险进行评价,通过算例阐述了基于层次分析法的模糊综合评价方法在城镇燃气管道风险评价中的应用,对保障其安全运行具有十分重要的意义。     

基于Choquet模糊积分的工程投标风险评估方法

在工程项目竞争性投标中,对于承包商来说,投标决策是一个多风险因素综合评价的问题,既要考虑自身实力,业主情况等主观条件,又要考虑项目的复杂性、自然条件等客观条件,同时还要兼顾经济、社会、环境、安全等各种因素。结合我国当前建设市场的现状和国内外相关文献,构建了工程项目投标风险因素评估系统层次结构和指标体系。针对在多因素指标的综合评价问题上,建立相互独立的指标比较困难和人们的主观评价往往存在非线性的特点,在模糊测度的基础上,提出一种基于Choquet模糊积分的新的工程投标多风险因素综合决策算法,详细论述该算法的计算步骤,并通过案例验证该方法的可行性、有效性和实用性。结果表明,该方法可以对多个项目进行投标风险评估排序,并且计算简单,可适用多种综合评价问题。     

Safety assessment of existing structures using a filtered fuzzy relation

Most constructed systems, as well as our infrastructure system, require regular inspection and reassessment so that proper actions can be taken to maintain their current usefulness. Although the quantitative information obtained from these inspections can be analyzed systematically and consistently using probability theory, a parallel analysis is not yet developed for the qualitative information obtained. A filtered fuzzy relation algorithm which utilizes the fuzzy set theory is developed to analyze the qualitative data methodologically. The analysis yields a safety function which shows the degree of belonging for each level of safety reduction from the original design reliability. A sensitivity analysis on the membership functions associated with the input data to the resulting safety function is also performed. The results indicate that, in general, the preciseness of these membership functions has little or no influence on the safety functions. Thus the filtered fuzzy relation algorithm has practical application in assessing existing membership functions.     

城市埋地燃气管道风险评估方法的适用性

综述了近年来国内外燃气管道风险评估的研究现状,分析了城市埋地燃气管道与长输管道的差异,探讨了穆氏法和模糊综合评价法在城市埋地燃气管道风险评估上的适用性。     

燃气管道的风险评估方法

论述了开展燃气管道风险评估的必要性，介绍了定性评估法、定量评估法、综合评估法等风险评估方法。阐明了我国进行燃气管道风险评估的困难和解决方法：     

基于模糊评价法的水麻路危岩灾害性风险评价

阐述了模糊评价法的基本原理,建立了数学模型,运用模糊综合评价法的数学建模方法评价水麻路沿线危岩体,并根据危险性将危岩体分为Ⅰ,Ⅱ,Ⅲ,Ⅳ四个等级,危险性由高到低,为水麻路沿线危岩体的防治提供了理论依据。     

城市燃气铸铁管道风险评估及应用

综述了近年来城市燃气管道与长输管道的风险评估方法现状与差异．介绍了模糊综合评价法在港华集团城市灰VI铸铁燃气管道风险评估中的应用。     

城市燃气管网运行安全风险评估研究进展

从定性、半定量、定量分析及新兴评估方法等方面介绍2009-2018年国内外燃气管网风险评估的研究进展。整理国内外城市燃气管网风险评估的指南标准,总结我国与国外相关规范标准的优缺点。整理相关软件开发情况,分析我国在软件开发方面的不足。对未来研究的发展趋势做出建议,例如加强耦合风险评估、定量评价法的研究,推进GIS的应用等。     

4种城镇燃气管网风险评估模型的比较

对目前我国研发的3种风险评估模型的结构、管道失效因素及其占系统总评分的权重与英国 Muhlbauer 的模型进行了比较,比较了各模型中第三方损害、腐蚀、设计、误操作等一级因素下的二级、三级因素的选取及权重。分析了这些评估模型在我国城镇燃气管网风险评估实践中的适用性及可操作性。     

A condition assessment model for oil and gas pipelines using integrated simulation and analytic network process

Even though they are safe and economical transportation means of gas and oil products around the world, pipelines can be subject to failure and degradation generating hazardous consequences and irreparable environmental damages. Therefore, gas and oil pipelines need to be effectively monitored and assessed for optimal and safe operation. Many models have been developed in the last decade to predict pipeline failures and conditions. However, most of these models used corrosion features as the sole factor to assess the condition of pipelines. Therefore, the objective of this paper was to develop a condition assessment model of oil and gas pipelines that considers several factors besides corrosion. The proposed model, which uses both analytic network process and Monte Carlo simulation, considers the uncertainty of the factors affecting pipeline condition and the interdependency relationships between them. The performance of the model was tested on an existing offshore gas pipeline in Qatar and was found to be satisfactory. The model will help pipeline operators to assess the condition of oil and gas pipelines and hence prioritise their inspections and rehabilitation requirements.     

风险评估在燃气管道的应用

文章论述了风险评估在燃气行业应用的必要性,介绍了风险评估的基础知识以及相关评估方法,并借鉴英国燃气管道风险评估系统,结合上海燃气的现状,阐明了目前风险评估的困难和解决方法。     

基于模糊理论的深基坑施工期风险评估

深基坑工程具有投资规模大、不确定性因素多、施工技术复杂、社会影响大等特点。这些特点决定了其施工期存在较多经济技术风险。因为风险具有客观性、必然性、多样性、动态性、模糊性等特点,风险很难用一个准确的值来确定,用模糊隶属函数曲线确定一个范围可以合理有效地描述深基坑施工期的风险。首先,专家根据制定的事故概率等级和损失等级对事故的概率和损失进行估值;然后,根据工程的复杂性、所调研专家水平的差异等来确定专家对估计值的确信程度,根据确信程度选择合适的隶属函数曲线,再由隶属函数曲线确定风险的范围;最后,将该范围与制定的风险接受准则相比较,确定基坑的风险等级。针对一个深基坑工程进行风险评估,得出了该基坑的风险等级。     

城镇燃气管网风险评估研究进展及建议

分析了我国城市燃气管网的现状,评述了国内风险评估的研究进展。提出了深入完善和发展城镇燃气管网风险评估管理技术的建议,包括建立管网安全运行知识专家库,在风险评估模型中引入适当的机制来输入完整性评价结果,在工程规划及初步设计阶段引入风险评估等。     

Use of fuzzy sets in developing code risk factors

Fuzzy set theory is used to produce risk factor values for a building code. Working through reliability indices, a transformation is developed to convert estimates of relative social importance of a building into code load factors. The importance estimates are found by surveying knowledgeable members of society or playing their roles, and by using fuzzy set theory to combine their views according to their significance. An extension, again using fuzzy set theory, brings in the use of multiple criteria on which to base judgements. An example gives risk factors close to those in an existing code.     

风险评估决策支持模型在实践中的应用

文章从上海燃气管道的现状入手,结合具体工程,提出了燃气风险评估系统模型,并且具体阐述了风险评估的测算与评分,该模型能诊断出燃气管道的状况,做到全面、系统地维护管理,实现燃气管道运行维护管理的科学化。     

埋地燃气管道的风险评估技术

阐述了我国进行燃气管道风险评估面临的挑战。用改进的故障树法建立埋地燃气管道阴极保护的风险评估模型,将风险评估模型的结果与现场实测、开挖结果相比较,二者基本一致。该风险评估模型为管道的安全运行及防腐系统的修复工作提供了科学依据。     

基于层次分析和模糊综合评判的管道风险评价

提出了基于层次分析(AHP)和模糊综合评判(FCE)的城市天然气管道风险评价模型.以层次分析的思路构建了城市天然气管道风险的四级层次结构,用层次分析法分析各级影响指标对上级指标的影响权重,曲专家评分法确定最底层指标,结合权重用模糊综合评价方法评判各上级指标的状况,评判出城市天然气管道总风险的级别.     

基于模糊集理论的边坡稳定性分析

岩土工程中的各种信息都存在模糊性,通过对边坡稳定性分析中模糊因素的研究,提出了一种工程边坡模糊稳定性分析的新方法,建立了边坡稳定性分析的模糊数学模型,并给出了相应的求解方法。该模型可以考虑分析中所涉及到的计算力学参数的模糊性。在分析岩土力学参数试验资料的基础上,结合专家经验提出了岩土力学参数的隶属函数构造方法,利用统计资料构造了边坡稳定性评价的隶属函数,并提出了边坡稳定性评价的具体分类指标和模糊安全系数隶属度的计算方法。实例研究表明边坡稳定性模糊分析方法是一种更为合理的研究边坡稳定性的新方法。     

油气长输管道风险管理技术探讨

阐述了油气长输管道风险管理的必要性,介绍了风险管理的基本概念和方法步骤,重点描述了现行风险评价方法中应用较广的指标评分法,并指出了现行风险管理方法中的不足,提出了将GIS技术和模糊综合评判法应用于长输管道风险管理之中。