JC法研究及其在桥梁结构可靠度中的应用

发布时间：2018-11-25 12:04

【摘要】：桥梁结构作为交通运输体系中的枢纽工程,占据着特殊地位,在国民经济和社会生活中起着举足轻重的作用。桥梁安全关系到我们每一个人。受自身材料和使用环境等多种因素的影响,钢筋混凝土桥梁结构性能逐渐劣化,存在着严重的安全问题。如何合理有效的评估桥梁的可靠性,是一项紧迫又意义重大的任务。本文在前人理论成果和已有研究的基础上,改进了原有氯离子扩散模型算法,并基于可靠度理论,探讨了桥梁劣化机制,对钢筋混凝土桥梁结构的可靠度评估和寿命预测进行了学习研究。首先,学习讨论了桥梁耐久性评估的方法和发展趋势,介绍了各种桥梁评估方法的适用性及优缺点,得出了可靠度理论在评估桥梁耐久性方面具有优越性,为钢筋混凝土桥梁可靠度的计算和寿命预测做准备。其次,由于氯腐蚀造成的混凝土桥梁的耐久性破坏严重,本文对氯离子引起的钢筋混凝土的破坏机理和发展过程作了详细阐述,在已有理论的基础上,提出了基于荷载影响、氯离子结合能力及环境(温湿度)的改进的氯离子扩散模型,该模型较之仅考虑单一因素影响的传统模型更加合理、更加准确。基于改进的氯离子扩散模型,修正了现有钢筋锈蚀模型,并做了对比。最后,详细介绍了验算点法(JC法),并对改进的JC法进行了对比,得出了其良好的适用性,在保证精度要求的同时,也具有良好的收敛性。并将上述方法应用到桥梁结构实例中,运用验算点法(JC法)计算得到了桥梁结构的可靠度及失效概率,并以此确定了其剩余使用寿命,并用MATLAB实现。
[Abstract]:As a pivotal project in transportation system, bridge structure occupies a special position and plays an important role in national economy and social life. Bridge safety concerns all of us. Due to the influence of its own material and using environment, the performance of reinforced concrete bridge structure is deteriorating gradually, and there are serious safety problems. How to evaluate the reliability of bridges reasonably and effectively is an urgent and significant task. In this paper, based on the previous theoretical achievements and previous studies, the original chloride diffusion model algorithm is improved, and the bridge deterioration mechanism is discussed based on the reliability theory. The reliability evaluation and life prediction of reinforced concrete bridge structures are studied. Firstly, the paper discusses the methods and development trend of bridge durability evaluation, introduces the applicability, advantages and disadvantages of various bridge evaluation methods, and concludes that the reliability theory has advantages in evaluating bridge durability. Preparation for reliability calculation and life prediction of reinforced concrete bridges. Secondly, due to the serious durability damage of concrete bridges caused by chlorine corrosion, the failure mechanism and development process of reinforced concrete caused by chloride ions are described in detail in this paper. The improved chloride diffusion model of chloride binding capacity and environment (temperature and humidity) is more reasonable and accurate than the traditional model which only considers the influence of a single factor. Based on the improved chloride diffusion model, the existing corrosion model of steel bar is modified and compared. Finally, the checking point method (JC method) is introduced in detail, and the improved JC method is compared, and its good applicability is obtained. The reliability and failure probability of bridge structure are calculated by JC method, and the residual service life is determined by MATLAB.
【学位授予单位】：河南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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