建筑结构安全性鉴定评级中的混凝土构件抗力验算

对建筑可靠性鉴定中混凝土构件承载力验算中的存在问题进行分析,并提出相应的验算评级方法,在建筑结构安全性鉴定的混凝土构件验算评级中具有实用意义。     

某热电公司管厂厂房可靠性鉴定

介绍了某公司管厂厂房可靠性鉴定的实例,通过对该厂房的检测鉴定找出厂房存在问题,并进行评级。     

某中学教学楼可靠性鉴定

通过对某中学教学楼进行的可靠性检测鉴定,介绍了民用可靠性鉴定的基本步骤及应检测内容,并对其抗震性能的鉴定结果、结构承载力验算、鉴定评级等方面进行了阐述,提出可靠性鉴定结论,并对存在的问题提出处理措施,从而为工程人员提供参考.     

提高钢筋混凝土构件安全性评级精度的探讨

本文对建筑可靠性鉴定中混凝土构件承载力验算及安全性评级存在的问题进行探讨,在建筑结构安全性鉴定工作中具有实用意义。     

试析某建筑火灾后结构损伤检测与鉴定评级

以某建筑火灾事件为例,探讨了火灾后该建筑可靠性鉴定评级的全过程,对可靠性鉴定评级过程中火作用调查、结构检测、鉴定评级等关键技术进行了详细分析,供类似工程参考。     

信息博采

《民用建筑可靠性鉴定标准》完成修订报批近日,由北京筑福国际工程技术有限责任公司参编的国家标准《民用建筑可靠性鉴定标准》已完成修订工作,提交住房和城乡建设部报批。《民用建筑可靠性鉴定标准》的主要内容包括总则、术语和符号、基本规定、调查与检测、构件安全性鉴定评级、构件使用性鉴定评级、子单元安全性鉴定评级、子单元使用性鉴定评级、鉴定单元安全性及使用性评级、民用建筑可靠性评级、民用建筑适修性评     

某管道支架检测鉴定与评级浅析

目前，越来越多的工业管道支架由于受自然及厂区环境的侵蚀以及超期服役等原因而存在不少病害和安全隐患。管道支架检测鉴定国家现行规范中没有专门的检测鉴定评级条文，为此，利用此次工程实践并根据现行的国家规范，有针对的对工业管道支架制定了检测鉴定评级标准，解决了现行规范无管道支架检测鉴定评级标准的问题，对管道支架这种工业特种结构的检测鉴定工程实践有一定的指导意义。     

钢筋混凝土多层工业厂房的可靠性鉴定

本文结合钢铁企业烧结主厂房的可靠性鉴定实例,阐述钢筋混凝土多层工业厂房鉴定中确定重点测区、验算分析及厂房可靠性评级中应注意的问题。     

某工业厂房的可靠性鉴定

通过对某工业厂房进行的可靠性鉴定,介绍了一般的混凝土结构工业厂房可靠性鉴定的基本步骤,并对其抗震性能的鉴定结果、结构承载力验算、鉴定评级等方面进行了阐述,结合经验提出一些建议,从而为工程人员提供参考。     

某钢结构包装厂房结构可靠性鉴定分析

根据某门式刚架厂房需要增加吊车荷载要求,对厂房使用状况进行检查,厂房主要构件基本完好。在此基础上对厂房进行了可靠性鉴定,依据《工业建筑可靠性鉴定标准》（GB50144-2008）,提出了可靠性评级,并给出了处理建议。     

钢结构的大气腐蚀模型

大气腐蚀是造成钢结构损伤的一个主要因素,并且是随时间渐变的,其可靠性分析属于时变可靠性的范畴,而腐蚀模型在其中起重要的作用.碳钢和低合金钢是钢结构的主要结构材料,本文在简述腐蚀机理和过程的基础上,对现有的碳钢和低合金钢的腐蚀模型进行总结,为钢结构腐蚀的可靠性评估提供借鉴.     

混凝土服役结构构件可靠性计算

分析混凝土碳化、钢筋锈蚀对混凝土结构构件的影响 ,提出容许碳化深度、容许钢筋锈蚀率和混凝土结构构件动态可靠度的概念 ;分析影响动态可靠度的关键因素 ,给出建立可靠度函数的方法。     

锈蚀钢筋混凝土结构承载力研究现状

从使用中的钢筋混凝土构件中锈蚀钢筋的力学性能的退化、粘结力的降低、承载力降低系数、结构可靠度以及钢筋锈蚀后的承载力计算方面,论述了锈蚀钢筋混凝土结构承载力研究的现状,分析了今后的研究趋势。     

Spatial time-dependent reliability analysis of corroding pretensioned prestressed concrete bridge girders

Accelerated pitting corrosion tests have been performed to obtain spatial and temporal maximum pit-depth data for prestressing wires. This data is then used to develop probabilistic models of pitting corrosion and strength capacity of 7-wire strands. The probabilistic model of pitting corrosion for strands is then combined with a non-linear Finite Element Analysis and probabilistic models of corrosion initiation and propagation to study the spatial and temporal effects of pitting corrosion on a typical pretensioned prestressed concrete bridge girder. The limit states considered are flexural strength and serviceability. The spatial time-dependent reliability analysis takes into account the uncertainties and variabilities related to material properties, dimensions, loads and corrosion parameters as well as the spatial variability of pitting corrosion of prestressing strands. Including the spatial variability of pitting corrosion in the reliability analysis increased both the probability of strength and serviceability failure when compared with a mid-span sectional analysis.     

Corrosion protection and assessment of weathering steel highway structures

Three studies, undertaken to investigate various issues related to the corrosion of weathering steel highway structures, are presented in this article. The first study examines the effects of corrosion products and pitting on weathering steel plate thickness measurements obtained using a standard ultrasonic gauge. The second evaluates the potential of several zinc-based coatings, including metallizing and zinc tape, as a way of protecting elements of existing corroded structures. The third study comprises a series of reliability analyses of composite weathering steel overpass structures with uniform corrosion occurring at various locations and rates. Based on this work, it is concluded that the examined coatings offer an effective way of improving the corrosion performance of weathering steel structures. From the reliability analysis study, it is concluded that corrosion can cause significant reductions in the service lives of weathering steel highway structures. The analysis results are seen to be most sensitive to the modelled corrosion conditions. Plate thickness measurements are seen to be vital for the assessment of weathering steel highway structures, due to the high uncertainty associated with the corrosion rate.     

Extent of spatially variable corrosion damage as an indicator of strength and time-dependent reliability of RC beams

A spatial time-dependent reliability model is developed for a RC beam subject to corrosion-induced pitting corrosion. The analysis considers the spatial and time-dependent variability of pitting corrosion and its effect on cover cracking and shear and flexural resistance. The model uses extreme value theory to predict maximum pit depth as a function of bar diameter and reinforcing bar length. The effect of corrosion on the mechanical behaviour of reinforcement and associated loss of ductility is also considered. A 1D spatial model is included where concrete properties, concrete cover and the surface chloride concentration are treated as random fields. The model is then used to predict the likelihood and extent of corrosion-induced cracking (corrosion damage). The spatial time-dependent reliability model allows the loss of structural capacity and reliability to be calculated conditional to the observed extent of corrosion damage. This allows the interaction between corrosion damage and loss of structural safety to be inferred for a deteriorating RC beam. It was found that the crack width at time of structural collapse is often well in excess of 1 mm. It was also found that the extent and location of severe cover cracking is an important indicator of structural reliability.     

钢筋混凝土结构锈胀寿命分析

通过试验和工程实测数据,建立了大气环境条件下混凝土中钢筋锈蚀速度和混凝土保护层开裂时锈蚀深度的预测模型。运用可靠度的原则,计算了钢筋混凝土结构的顺筋开裂耐久年限及对应的可靠指标,分析了影响钢筋混凝土结构顺筋开裂耐久性的主要因素。     

氯盐侵蚀下修正混凝土桥梁的结构可靠性退化模型

结构退化可靠性(概率论)模型已经被用于计算结构的失效性。考虑钢筋混凝土腐蚀初始点、腐蚀速度以及时变荷载提出相应的修正模型。耐久性设计规范中已考虑混凝土桥梁的全寿命周期的可靠性分析以及时变荷载,但对于耐久性设计考虑不周,没有考虑到除冰盐的运用将引起长期退化和结构安全度的降低。另外,保护层厚度不足或水灰比过高也会增加结构失效的可能性。     

多种腐蚀因素作用下钢筋混凝土结构的可靠度分析

钢筋混凝土结构可能会同时受到多种腐蚀介质的侵蚀。本文给出了钢筋混凝土结构常见的几种腐蚀失效模式。考虑了失效模式间的相关性对结构整体可靠度的影响,用系统可靠度方法分析了多种腐蚀因素作用下钢筋混凝土结构的可靠度并给出了算例。该分析方法计算简便,可以作为多种腐蚀介质环境下结构可靠度分析的参考方法。     

服役钢筋混凝土结构模糊碳化寿命的研究

混凝土碳化及由此引起的钢筋锈蚀是影响钢筋混凝土结构耐久性的最主要因素,碳化寿命理论是结构寿命研究的基础。根据结构所处环境相对湿度的不同,对钢筋开始锈蚀时间进行修正,用模糊随机可靠度理论分析结构的碳化寿命。