环境作用下钢—混凝土组合梁桥全寿命成本研究

发布时间：2018-01-15 03:04

本文关键词：环境作用下钢—混凝土组合梁桥全寿命成本研究　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：暴露于环境侵蚀下的钢-混凝土组合梁桥,其结构的性能会随着服役时间而发生退化。因此为了保证组合梁桥全寿命期间的安全性能,需要对其进行检测和维修。然而,不恰当的维修会导致组合梁全寿命成本过高。因此,本文采用马尔科夫过程对组合梁桥全寿命成本以及维修策略进行研究,主要研究工作包括：(1)研究了环境侵蚀下钢-混凝土组合梁结构的耐久性,着重分析了组成组合梁部件的混凝土、栓钉以及钢梁的耐久性。通过查阅国内外文献,给出了混凝土强度老化、栓钉截面损失以及钢梁截面损失随时间变化的耐久性模型；在耐久性分析的基础上,综合考虑环境侵蚀作用下混凝土老化、栓钉锈蚀、钢梁锈蚀效应对组合梁弯曲抗力的影响,建立了环境作用下钢-混凝土组合梁弯曲抗力退化模型,并分析了钢-混凝土组合梁桥构件和体系时变可靠度。(2)研究了环境作用下圆形钢管混凝土组合短柱的耐久性,着重分析了组合短柱钢管的耐久性；利用钢材腐蚀随时间变化的指数模型,综合考虑了荷载和环境侵蚀对圆形钢管混凝土短柱轴压承载能力的影响,建立了圆形钢管混凝土短柱轴压抗力时变模型,分析了短柱轴压抗力的时变可靠度指标；分析了三种因素：不同环境、荷载比、钢管壁厚对组合短柱轴压抗力时变可靠度指标的影响。(3)研究了钢-混凝土组合梁桥全寿命成本的构成,建立了组合梁桥全寿命成本经济评价模型；以组合梁全寿命总成本最小为目标,组合梁桥的目标可靠度指标为约束,建立了基于MDP的钢-混凝土组合梁桥全寿命成本分析模型；采用实例具体分析了钢-混凝土组合梁全寿命成本模型,深入研究了组合梁全寿命各阶段成本以及最优维修策略,研究了结构初始弯曲抗力、侵蚀环境、失效成本、折现率因素对全寿命总成本以及维修策略的影响。
[Abstract]:The structural performance of steel-concrete composite beam bridges exposed to environmental erosion will degrade with the service time, so in order to ensure the safety performance of composite beam bridges during their lifetime. It needs to be inspected and repaired. However, improper maintenance will lead to the high total life cost of composite beam. Therefore, this paper uses Markov process to study the whole life cost and maintenance strategy of composite beam bridge. The main research work includes: (1) the durability of steel-concrete composite beam structures under environmental erosion is studied, and the concrete components of composite beams are emphatically analyzed. Durability of studs and steel beams. The durability models of aging strength of concrete, cross-section loss of studs and cross-section losses of steel beams with time are given by referring to domestic and foreign literatures. On the basis of durability analysis, the effects of concrete aging, pin corrosion and steel beam corrosion on the bending resistance of composite beams are considered comprehensively. The degradation model of bending resistance of steel-concrete composite beams under environmental action is established. The durability of circular concrete-filled steel tubular composite short columns under environmental action is studied, with emphasis on the durability of composite short columns. Based on the exponential model of steel corrosion varying with time and considering the influence of load and environmental erosion on the bearing capacity of circular concrete-filled steel tubular short columns, a time-varying model of axial compression resistance of circular concrete filled steel tubular short columns is established. The time-varying reliability index of axial compression resistance of short columns is analyzed. This paper analyzes three factors: the influence of different environment, load ratio, steel tube wall thickness on the time-varying reliability index of axial compression resistance of composite short columns. The composition of life cost of steel-concrete composite beam bridge is studied. The economic evaluation model of the whole life cost of composite girder bridge is established. Taking the minimum total life cost of composite beam as the goal and the reliability index of composite beam bridge as the constraint, the model of steel-concrete composite beam bridge life cost analysis based on MDP is established. The life cost model of steel-concrete composite beam is analyzed with an example. The cost of every stage of life and the optimal maintenance strategy of composite beam are deeply studied. The initial bending resistance of structure and the environment of erosion are also studied. Effect of failure cost, discount factor on total life cost and maintenance strategy.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.7

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