在役预应力混凝土连续刚构桥承载力时变可靠度研究
发布时间：2018-12-09 11:11
【摘要】：预应力混凝土连续刚构桥在使用过程中，不仅要承受车辆、人群、风、雪、地震等外力的作用，而且还要受到环境、有害化学物质的侵蚀，，同时桥梁所采用材料的自身性能也会不断退化，如混凝土碳化、裂缝、钢筋锈蚀等等，随着运营时间和交通量的增加，不少连续刚构桥出现了不同程度的病害情况，集中体现在腹板斜裂缝、顶底板纵向裂缝、底板的横向裂缝、以及主跨的持续下挠等，导致许多在役连续刚构桥承载能力不足。 续刚构桥出现该类问题后的安全状况如何，未出现该类问题的安全状况又如何，如何进行评估，对应又该采取什么样的处理措施，是我们必须解决的问题。这就需要我们对在役预应力混凝土连续刚构桥，进行恰如其分的评估。 国内外对桥梁结构的可靠度问题研究相对较多，而对桥梁结构的时变可靠度问题的研究相对较少。本文针对预应力混凝土连续刚构桥的结构特点，在总结已有研究成果的基础上，对承载能力极限状态下的时变可靠度问题进行了深入的研究，主要工作内容包括以下几个方面： ①可靠度基本理论分析研究 着重论述了可靠度理论的基本原理，基本概念，并且介绍了计算构件时变可靠度的计算方法，体系时变可靠度的计算方法、目标可靠度以及评估的准则等等. ②连续刚构桥常见病害及其主要影响因素分析 对连续刚构桥常见的病害进行了总结，并结合具体的工程实例进行相应的分析，接着将影响连续刚构抗力的主要因素进行了分析总结。 ③预应力混凝土梁桥结构承载能力时变可靠度研究 首先参照规范对荷载效应的统计参数进行了总结分析，其次针对抗力衰减的问题，对抗力主要影响因素混凝土强度、预应力筋的时变模型进行了相应的分析，尤其是对预应力筋锈蚀后的剩余截面面积、力学性能、有效预应力损率进行大胆创新、合理假设，提出了抗力的时变模型。 ④连续刚构桥主梁抗弯承载力时变可靠度计算分析 首先结合规范和前面的理论，提出抗力的时变模型，进而参照相应的文献提出了结构失效的标志以及如何处理随机过程中的变量。 ⑤连续刚构桥承载力时变可靠度实例分析 以云南某连续刚构桥为例，利用软件Midas/civil建立了有限元计算模型，并根据时变可靠度理论分析研究各个时变随机变量，利用MATLAB采用了JC法和蒙特卡洛方法(Monte Carlo法)的计算原理，编制了时变可靠度计算程序，进而计算出预应力混凝土连续刚构桥承载能力的时变可靠度，在此基础上与目标可靠度进行对比，预测其剩余寿命。
[Abstract]:During the use of prestressed concrete continuous rigid frame bridges, they not only have to bear the effects of external forces such as vehicles, crowds, wind, snow and earthquakes, but also suffer from the erosion of environment and harmful chemicals. At the same time, the properties of the materials used in the bridges will be degraded continuously, such as concrete carbonization, cracks, steel corrosion and so on. With the increase of operation time and traffic volume, many continuous rigid frame bridges have different degrees of disease. It is mainly reflected in the web slanting crack, the longitudinal crack in the top and bottom plate, the transverse crack in the bottom plate, and the continuous deflection of the main span, which leads to the insufficient bearing capacity of many existing continuous rigid frame bridges. It is necessary to solve the safety condition of the continuous rigid frame bridge after the occurrence of this kind of problem, the safety condition of the non-existent problem, how to evaluate and how to deal with the corresponding measures. This requires us to properly evaluate the existing prestressed concrete continuous rigid frame bridge. There are many researches on the reliability of bridge structure at home and abroad, but less on the time-varying reliability of bridge structure. In this paper, according to the structural characteristics of prestressed concrete continuous rigid frame bridge, on the basis of summarizing the existing research results, the time-varying reliability under the limit state of bearing capacity is studied deeply. The main work includes the following aspects: 1 the basic theory of reliability is analyzed and studied. The basic principle and concept of reliability theory are discussed, and the calculation method of time-varying reliability of components is introduced. The calculation method of system time-varying reliability, target reliability and evaluation criterion, etc. 2 the common diseases of continuous rigid frame bridge and their main influencing factors are summarized, and the corresponding analysis is made on the basis of concrete engineering examples. Then the main factors affecting the resistance of continuous rigid frame are analyzed and summarized. (3) the time-varying reliability of the bearing capacity of prestressed concrete beam bridge is studied. Firstly, the statistical parameters of the load effect are summarized and analyzed with reference to the code. Secondly, the resistance attenuation problem, the main factor affecting the strength of concrete, is the antagonistic force. The time-varying model of prestressing tendons is analyzed, especially the time-varying model of resistance is put forward by the bold innovation of residual section area, mechanical properties and effective prestress loss rate after corrosion of prestressed tendons. (4) calculation and analysis of time-varying reliability of flexural bearing capacity of main girder of continuous rigid frame bridge first of all, a time-varying model of resistance is put forward in combination with the code and the previous theory. Then the structural failure signs and how to deal with the variables in the random process are put forward according to the corresponding literatures. Case study on Time-varying Reliability of continuous Rigid-Frame Bridge; A continuous rigid frame Bridge in Yunnan Province is taken as an example. Finite element calculation model is established by using software Midas/civil, and each time-varying random variable is analyzed and studied according to time-varying reliability theory. Using the calculation principle of JC method and Monte Carlo method (Monte Carlo method) of MATLAB, the time-varying reliability calculation program is compiled, and then the time-varying reliability of prestressed concrete continuous rigid frame bridge is calculated. On this basis, compared with the target reliability, the residual life of the target is predicted.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23;U441
本文编号：2369280
[Abstract]:During the use of prestressed concrete continuous rigid frame bridges, they not only have to bear the effects of external forces such as vehicles, crowds, wind, snow and earthquakes, but also suffer from the erosion of environment and harmful chemicals. At the same time, the properties of the materials used in the bridges will be degraded continuously, such as concrete carbonization, cracks, steel corrosion and so on. With the increase of operation time and traffic volume, many continuous rigid frame bridges have different degrees of disease. It is mainly reflected in the web slanting crack, the longitudinal crack in the top and bottom plate, the transverse crack in the bottom plate, and the continuous deflection of the main span, which leads to the insufficient bearing capacity of many existing continuous rigid frame bridges. It is necessary to solve the safety condition of the continuous rigid frame bridge after the occurrence of this kind of problem, the safety condition of the non-existent problem, how to evaluate and how to deal with the corresponding measures. This requires us to properly evaluate the existing prestressed concrete continuous rigid frame bridge. There are many researches on the reliability of bridge structure at home and abroad, but less on the time-varying reliability of bridge structure. In this paper, according to the structural characteristics of prestressed concrete continuous rigid frame bridge, on the basis of summarizing the existing research results, the time-varying reliability under the limit state of bearing capacity is studied deeply. The main work includes the following aspects: 1 the basic theory of reliability is analyzed and studied. The basic principle and concept of reliability theory are discussed, and the calculation method of time-varying reliability of components is introduced. The calculation method of system time-varying reliability, target reliability and evaluation criterion, etc. 2 the common diseases of continuous rigid frame bridge and their main influencing factors are summarized, and the corresponding analysis is made on the basis of concrete engineering examples. Then the main factors affecting the resistance of continuous rigid frame are analyzed and summarized. (3) the time-varying reliability of the bearing capacity of prestressed concrete beam bridge is studied. Firstly, the statistical parameters of the load effect are summarized and analyzed with reference to the code. Secondly, the resistance attenuation problem, the main factor affecting the strength of concrete, is the antagonistic force. The time-varying model of prestressing tendons is analyzed, especially the time-varying model of resistance is put forward by the bold innovation of residual section area, mechanical properties and effective prestress loss rate after corrosion of prestressed tendons. (4) calculation and analysis of time-varying reliability of flexural bearing capacity of main girder of continuous rigid frame bridge first of all, a time-varying model of resistance is put forward in combination with the code and the previous theory. Then the structural failure signs and how to deal with the variables in the random process are put forward according to the corresponding literatures. Case study on Time-varying Reliability of continuous Rigid-Frame Bridge; A continuous rigid frame Bridge in Yunnan Province is taken as an example. Finite element calculation model is established by using software Midas/civil, and each time-varying random variable is analyzed and studied according to time-varying reliability theory. Using the calculation principle of JC method and Monte Carlo method (Monte Carlo method) of MATLAB, the time-varying reliability calculation program is compiled, and then the time-varying reliability of prestressed concrete continuous rigid frame bridge is calculated. On this basis, compared with the target reliability, the residual life of the target is predicted.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.23;U441
【参考文献】
相关期刊论文 前9条
1 涂永明,吕志涛;应力状态下混凝土的碳化试验研究[J];东南大学学报(自然科学版);2003年05期
2 安琳;欧阳平;郑亚明;;锈坑应力集中对钢筋力学性能的影响[J];东南大学学报(自然科学版);2005年06期
3 牛荻涛，王庆霖;一般大气环境下混凝土强度经时变化模型[J];工业建筑;1995年06期
4 王鹏;王福敏;张力;;在役混凝土梁桥时变可靠度评估技术研究综述[J];公路交通技术;2012年06期
5 张建仁,刘扬;混凝土桥梁构件服役期的抗力概率模型[J];长沙理工大学学报(自然科学版);2004年01期
6 彭建新;邵旭东;张建仁;;考虑气候变化的受碳化腐蚀先张预应力混凝土梁时变可靠性评估[J];长沙理工大学学报(自然科学版);2010年02期
7 徐力,杨小平,刘荣桂,姜小云;预应力结构设计使用寿命模型[J];江苏大学学报(自然科学版);2002年01期
8 曾严红;顾祥林;张伟平;黄庆华;;锈蚀预应力筋力学性能研究[J];建筑材料学报;2010年02期
9 罗小勇;邹洪波;施清亮;;不同应力状态下混凝土碳化耐久性试验研究[J];自然灾害学报;2012年02期
相关博士学位论文 前1条
1 杜斌;既有预应力混凝土桥梁结构可靠度与寿命预测研究[D];西南交通大学;2010年
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