基于时变可靠度的锈蚀混凝土结构全寿命成本模型

陆春华+袁思奇

摘要：為了分析混凝土结构在氯盐环境下的全寿命周期成本，基于现有氯离子扩散模型和裂缝宽度预测模型，采用MATLAB软件进行Monte-Carlo抽样模拟，建立结构失效概率与可靠度指标的拟合公式。通过研究维护-加固措施对可靠度指标的影响，建立全寿命周期内维护-加固费用计算评估方法，并以混凝土桥梁结构为例计算了全寿命周期维护-加固成本。结果表明：失效概率与可靠度指标可用以失效概率等于0.1为界的分段函数进行描述；维护-加固效果持续时间对结构构件服役年限延长的影响最显著；当保护层厚度取60 mm时，维护-加固阶段费用有明显下降，较保护层厚度取40 mm时减少25%～50%。

关键词：混凝土结构；氯盐侵蚀；锈胀裂缝宽度；时变可靠度；全寿命成本

中图分类号：TU375 文献标志码：A

文章编号：1673-2049（2017）02-0071-08

Abstract：In order to analyze the life-cycle cost of concrete structures in chloride environment， the existing chloride diffusion model and crack width prediction model were used， Monte-Carlo sampling simulation was carried out using MATLAB software， and the fitting formula of structural failure probability and reliability index was established. The calculation method of maintenance-reinforcement cost in the whole life cycle was established combining the influence of maintenance-reinforcement measures on reliability index， and the life-cycle maintenance-reinforcement cost was calculated by taking concrete bridge structure as an example. The results show that the failure probability and reliability index can be described by piecewise function with failure probabilities being 0.1 as boundary. The duration of maintenance-reinforcement effect has the most obvious effect on service life extension of structural members. When the thickness of protective layer is 60 mm， the maintenance-reinforcement cost decreases obviously， and is reduced by 25%-50% compared with the thickness of protective layer 40 mm.

Key words：concrete structure； chloride erosion； corrosion crack width； time-varying reliability； life-cycle cost

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现代物业杂志社

2020-08-23