【作者】 李庆；

【导师】 管品武；

【作者基本信息】 郑州大学 ， 结构工程， 2013， 硕士

【摘要】 预应力混凝土桥梁在服役过程中,由于受到结构自重、车辆荷载、冲击荷载、疲劳、温度等荷载作用以及碳化、氯离子侵蚀等环境作用和混凝土开裂等材料损伤因素的影响,难以避免的会出现诸多耐久性问题,不仅影响桥梁结构的正常使用,还会给交通运营带来一系列的安全隐患。本文在已有国内外研究的基础之上,结合河南地区预应力混凝土桥梁服役环境特征,分析其主要耐久性病害及影响因素,综合运用概率理论、电化学理论以及时变可靠度理论等基本理论和方法,确定结构抗力劣化性能的实用计算方法,并建立预应力混凝土桥梁承载能力评价体系。主要的研究内容包含以下几个方面：(1)系统阐述本课题的国内外研究概况,并指出当前研究中存在的一些问题。(2)结合河南地区混凝土桥梁的使用状况,对预应力混凝土桥梁中存在的耐久性病害进行归类、整理,确定该地区耐久性病害的主要影响因素并加以分析,为下一步推断其材料性能退化及变形机理模型提供依据。(3)在已有钢筋混凝土材料性能退化规律研究的基础上,结合本地区检测结果,引入时间参数,研究适合本地区桥梁服役环境的混凝土碳化及力学性能变化、钢筋锈蚀及力学性能变化和氯离子扩散规律。(4)在已有承载力演变规律的基础之上,考虑荷载效应与结构抗力的随机性特征,结合《公路桥梁承载能力检测评定规程》分析桥梁结构抗力时变规律,构建典型预应力混凝土桥梁时变体系可靠度评价模型,并结合工程实例开展应用。更多还原

【Abstract】 Due to the impact of structural weight, vehicle load, impact load, fatigue, temperature and the environmental effects of concrete carbonization, chloride ion penetration as well as the material damage of concrete cracking and so on, it is difficult for the prestressed concrete bridge to avoid the emergence of many durability problems, which not only affect the normal use of the bridge structure, but also bring a series of security risks.Based on the research status at home and abroad, combined with the service environmental features about prestressed concrete bridge on the Henan area, the main durability diseases and its influence factors can be analyzed, and the applied calculation methods of structural resistance deterioration performance are derived from the probability theory, the electrochemical theory as well as the time-variant-reliability theory comprehensively, meanwhile, the bearing capacity evaluation system of prestressed concrete bridge will be established eventually. The main contents in this paper are as follows:(1) The research status at home and abroad is elaborated systematically, and the problems existing in the current study are showed.(2) According to the usage of the bridges on the Henan area, the durability diseases are classified, the main factors can be confirmed and analyzed, which provide a basis for inferring the material degradation and deformation mechanism model next chapters.(3) Combined with the detection result in Henan, the laws of concrete carbonization, steel bar corrosion and chloride diffusion which are suitable for this service environment are studied by introducing time parameter on the basis of existing degradation rule research of reinforced concrete material.(4) On the basis of existing evolution rule of bearing capacity, considering the stochastic nature of the load effect and structural resistance, the time-varying regularity of the bridge structure resistance will be analyzed combined with the specification for inspection and evaluation of load-bearing capacity of highway bridges; typical time-varying system reliability evaluation model of the prestressed concrete bridge is established and used to a project.更多还原