论城市生命线工程系统的防（火）灾可靠度分析

阐述了保证和提高城市生命线工程系统的防（火）灾可靠度的重要意义。引用了大量火灾及故障案例说明评估城市生命线工程内消防系统的可靠度是一项复杂的系统工程。介绍了当前在不同行业中采用的对复杂系统的可靠度进行评估的一些方法。在对这些评估方法进行比较后介绍了故障树分析法的优、缺点，并指出这种方法完全可以胜任对城市生命线工程系统的防（火）灾可靠度的分析工作。     

城市燃气输配管网的可靠性评价

分析了管网失效的早期失效期、偶然故障期和耗损失效期的特点,探讨了偶然故障期管网系统的可靠性评价方法。     

An Efficient Method for Evaluating Origin-Destination Connectivity Reliability of Real-World Lifeline Networks

Abstract:   A method of analyzing origin-destination (O-D) connectivity reliability of real-world lifeline networks is proposed in this research. This research is novel because, for real-world lifeline networks with thousands of vertices and links, evaluating O-D connectivity is computationally infeasible with traditional methods, for example, combinatorial methods. It is postulated that the O-D connectivity problem for the actual network can be converted into a virtual problem, while the computation for this problem is fast even for large networks. Hence, it is applicable to real-world lifeline networks. When combined with reliability analysis methods, the proposed method can be used to efficiently solve realistic O-D connectivity reliability problems for real-world lifeline networks. Besides, a rating method is also proposed to rank critical links, that is, links that have great influence on the O-D connectivity. The proposed framework should be valuable for management and reliability analysis of real-world lifeline networks.     

平面钢框架结构极限承载的体系可靠度评价

为了将基于结构体系可靠度的设计理论运用到钢框架结构的设计中,必须对工程中钢框架结构的体系可靠度做出实际的评价。本文考虑影响钢框架结构体系可靠度的主要因素,并根据现有的统计资料,对钢框架结构的体系可靠度做出比较实际的评价,为实现基于整体可靠度的钢框架结构设计奠定了一定的理论基础。     

钢筋混凝土梁抗震可靠度校核以及强剪弱弯设计可靠性分析

对按现行结构抗震设计规范设计的钢筋混凝土梁进行受弯、受剪可靠度分析,研究了不同荷载比值（地震作用与自重荷载比值）、不同材料强度等级和不同配筋率对梁可靠度的影响。在此基础上,分析了梁“强剪弱弯”设计的可靠性。分析结果表明,按现行规范设计的钢筋混凝土梁“强剪弱弯”设计的可靠性较低,需提高剪切增强系数,来满足设计需要。在分析梁的可靠度时,采用了MonteCarlo随机模拟法。     

Safety Assessment Using Imprecise Reliability for Corrosion-Damaged Structures

Abstract:   Safety assessment procedure including imprecise reliability for corrosion-damaged structures is proposed in this article. The proposed procedure may be used for the safety assessment of corroded structures when the data for safety analysis are insufficient or when a decision for safety management is urgently required. In case exact measurement such as nondestructive test cannot be utilized to assess a corroded point for any reason, expert's estimation with simple visual inspection based on the data of nondestructive test at near point can be used. The system reliability-based safety assessment may then be performed approximately but rationally by simply converting the qualitative expert's estimation to quantitative terms in this proposed procedure. Moreover, the approximate safety expressed as a safety range could also be evaluated effectively in hazardous environments such as typhoon where data collection for deterioration is very difficult. The proposed safety assessment procedure using the imprecise reliability was also applied to a cable-stayed bridge in Korea to demonstrate its effectiveness and applicability.     

既有建筑钢结构可靠性评估方法探讨

如今,不同体系的建筑钢结构开始被逐渐的使用在建筑施工当中。但使用建筑钢结构的同时产生了较多的危险事故。因此,必须对钢结构进行科学合理的检测和评估,从而使其更加可靠合理,为建筑物的安全性提供保障。     

建筑结构体系可靠性评价的一个新方法

本文在研究了建筑结构体系特点的基础上，根据体系可靠性的经典定义，提出了一个评价结构体系可靠性的新的方法。本文的主要观点是根据结构构件功能的不同，将构件分成直接构件与间接构件，并根据直接构件的使用功能指标及其可能失效概率，评价结构体系的可靠性。文中给出了直接构件功能指标与直接构件失效概率的定义及计算方法。     

某中学教学楼可靠性评估分析

通过对某中学教学楼进行的可靠性检测鉴定,介绍了可靠性鉴定的基本步骤及应检测内容,并对结构现状、结构安全性、正常使用性、结构抗震性能、结构适修性的鉴定等方面进行了阐述,提出可靠性鉴定结论,并对存在的问题提出处理措施,为工程人员提供参考。     

暴雨荷载下平台布局、上部重量和结构可靠性的关系

通过对暴雨荷载下,西北海湾中简易护套、顶托、布局等坍塌行为的对比,研究了平台布置与结构可靠性的关系。采用两种不同性能分析的方法确定极限强度,对确定的结构,给出了截然不同的RSR值。评估了上部重量变化对结构可靠性的影响,结果发现可靠性与结构的布局有关,这种影响在现行的指南中没有提及。研究也显示在不同的平台布局以及相同环境下,同一组固定荷载和环境荷载因素具有不同的可靠性。而且,在某些情况下,采用工作应力设计方法比荷载-抗力设计系数法可以得到更一致的可靠性结果。     

基于可靠度理论的焊接结构疲劳寿命评估

以16MnR钢的焊接结构为例,视主要变量为不确定的,考虑Taylor展开的方法求解一般函数的均值和标准差。根据断裂判据,采用JC法(国际结构安全度联合委员会JCSS推荐)对这种结构进行疲劳可靠性分析,并运用概率断裂力学方法进行给定可靠度下的剩余疲劳寿命计算。算例结果表明,JC法计算精度较高,采用断裂力学方法估算含裂纹构件的剩余疲劳寿命是可行的。     

既有铁路钢筋混凝土梁桥动态可靠性评估

介绍了既有桥梁结构的动态可靠性分析方法,提出了桥梁的恒载概率模型、活载概率模型及抗力概率模型,并对可靠度计算方法中的验算点法进行了介绍。以一座既有铁路钢筋混凝土梁桥为工程背景,计算了该桥的活载效应统计参数、恒载效应统计参数及抗力统计参数等,利用验算点法计算了桥梁结构构件的可靠度指标,又采用PNET方法分析了整个桥梁体系的可靠性,最后给出了桥梁的可靠性评估结果。结果显示动态可靠性评估应用于铁路钢筋混凝土梁桥可以得到较好的评估结果。     

基于改进一次二阶矩法的桥梁颤振可靠性评价

随着以悬索桥和斜拉桥为代表的大跨度柔性桥梁的发展,由风与桥梁的相互作用而引起桥梁颤振稳定问题倍受关注,而在各种随机因素作用下的桥梁颤振可靠性评价也受到了人们的重视.在对传统的一次二阶矩可靠度计算方法改进的基础上,对国内14座大跨度桥梁进行了颤振可靠性评价.通过与Monte Carlo数值模拟结果的对比表明,所提出的改进一次二阶矩方法能够有效提高小失效概率条件下的可靠度计算精度.     

某钢结构工业厂房的可靠性评估

某钢结构工业厂房在使用过程中柱基发生了一定程度的侧移,而且在该厂房附近即将进行打桩施工,为了解该厂房结构的运行现状并预估打桩振动对该厂房的影响,对该结构整体建模进行分析。分析的结果及相应的维护加固建议可供同类工程参考。     

Reliability of Steel Truss Roof Systems Under Variable Snow Load Profiles

The probabilistic safety analysis of steel truss roof systems under variable snow load profiles is investigated. The roofs of structures such as industrial buildings or sports halls, which require wide areas, are frequently subjected to unexpectedly high loads. Therefore, compared to the residential buildings, that type of buildings often comes across failure or prohibition of usage. Probabilistic techniques are utilized for the analysis of the problem. Thirty-six steel roof structures with different structural dimensions and load variations are modelled and their failure probabilities are calculated. In this paper, a complicated stochastic analysis is reduced to the solution of a load–resistance (S–R) problem by utilizing sensitivity analyses. Firstly, the structures were designed through structural analyses, and then the sensitivity analyses were conducted to understand the response of the structure to the load and to the span-length parameters. In this paper, a reliability study which gradually monitors the effect of geometrical parameters on the failure trend is presented. Three different snow load distribution functions were used. The relation between failure, and load or structural dimension variations was investigated. The results obtained in this study are discussed and compared with the results from the literature for similar structures subjected to snow loads. It is observed that for the snow load distributions with high standard deviations the structural reliability indices may give results below the target safety levels of the design codes. Finally, the assessment of the results shows that the effect of the standard deviation of the snow load on failure probability is much more than the effect of intensity of the nominal snow load.     

Optimization of Water Supply Systems: Risk Analysis and Reliability of Supply

T he problem of determining minimum premissible storage in the optimization of water distribution networks is assessed by means of evaluating the reliability of the system operation during range crisis events. Reliability is treated in both a deterministic and probabilistic manner, and an illustration of the analysis given for a typical scenario on an existing network.     

Probabilistic Neural Network for Reliability Assessment of Oil and Gas Pipelines

A fuzzy artificial neural network (ANN)–based approach is proposed for reliability assessment of oil and gas pipelines. The proposed ANN model is trained with field observation data collected using magnetic flux leakage (MFL) tools to characterize the actual condition of aging pipelines vulnerable to metal loss corrosion. The objective of this paper is to develop a simulation-based probabilistic neural network model to estimate the probability of failure of aging pipelines vulnerable to corrosion. The approach is to transform a simulation-based probabilistic analysis framework to estimate the pipeline reliability into an adaptable connectionist representation, using supervised training to initialize the weights so that the adaptable neural network predicts the probability of failure for oil and gas pipelines. This ANN model uses eight pipe parameters as input variables. The output variable is the probability of failure. The proposed method is generic, and it can be applied to several decision problems related with the maintenance of aging engineering systems.     

Reliability Assessment of Reinforced Concrete Walls Degraded by Aggressive Operating Environments

Abstract:  The time-dependent reliability of a reinforced concrete structural wall in which the strength degrades as the result of an aggressive environment can be evaluated from a probabilistic model of defect growth. The effect of multiple defects or zones of damage in a section is considered. Although defects initiate and grow randomly, failure may occur at the section where the environmental attack is most severe rather than at the section where the load effect is largest. The strength of a wall is determined by the section with the least safety margin. A nonuniform distribution of stresses at a section leads to a reduction in strength that is a nonlinear function of section area lost. The methods are illustrated using a low-rise reinforced concrete wall subjected to flexure and shear forces in which the outer part of the cross-section area is lost due to expansive aggregate reactions.     

燃气输配管网供气可靠性评价方法

燃气管网系统是一种可修复的系统,对这种系统需要研究其可靠性问题。燃气管网发生故障使系统的完整性状态发生变化,可以看作齐次马尔柯夫过程。考虑管网的维修性,结合关于管网阀门规则配置的研究成果,提出基于水力工况的燃气管网供气可靠度计算方法,使燃气管网可靠性评价实用化。     

城市排水系统改造方案的综合评价方法探讨

为合理评价城市排水系统方案,探讨了评价方法的选用,并用加权平均法和模糊综合评价法对城市排水系统方案进行了综合评价,得到了合理的评价结果。