Probabilistic durability assessment of concrete structures in marine environments: Reliability and sensitivity analysis
Probabilistic durability assessment of concrete structures in marine environments: Reliability and sensitivity analysis
复制标题
海洋环境中混凝土结构的概率耐久性评估：可靠性和敏感性分析
DOI：
10.1007/s13344-017-0008-3
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发表时间：
2017
影响因子：
1.6
通讯作者：
Li Bing
中科院分区：
文献类型：
--
作者：
Yu Bo;Ning Chao-lie;Li Bing
从可靠性和敏感性分析的角度提出了海洋环境下混凝土结构耐久性评估的概率框架，该框架考虑了环境、材料、结构和执行条件下的不确定性。首先建立了氯化物进入的时间相关概率模型，以考虑各种控制参数的变化，例如氯化物浓度、氯化物扩散系数和年龄因子。然后采用Nataf变换将非正态随机变量从原始物理空间变换到独立的标准正态空间。解析得出耐久性极限状态函数及其相对于原始物理参数的梯度向量，在此基础上采用一阶可靠性方法分析海洋环境下混凝土结构的时变可靠性和参数敏感性。通过与二阶可靠性法和蒙特卡洛模拟的比较，验证了该方法的准确性。最后，还研究了环境条件、材料性能、结构参数和施工条件对海洋环境中混凝土结构随时间变化的可靠性的影响。所提出的概率框架可以在海洋环境中老化混凝土结构维护和修复的决策算法中实现。
A probabilistic framework for durability assessment of concrete structures in marine environments was proposed in terms of reliability and sensitivity analysis, which takes into account the uncertainties under the environmental, material, structural and executional conditions. A time-dependent probabilistic model of chloride ingress was established first to consider the variations in various governing parameters, such as the chloride concentration, chloride diffusion coefficient, and age factor. Then the Nataf transformation was adopted to transform the non-normal random variables from the original physical space into the independent standard Normal space. After that the durability limit state function and its gradient vector with respect to the original physical parameters were derived analytically, based on which the first-order reliability method was adopted to analyze the time-dependent reliability and parametric sensitivity of concrete structures in marine environments. The accuracy of the proposed method was verified by comparing with the second-order reliability method and the Monte Carlo simulation. Finally, the influences of environmental conditions, material properties, structural parameters and execution conditions on the time-dependent reliability of concrete structures in marine environments were also investigated. The proposed probabilistic framework can be implemented in the decision-making algorithm for the maintenance and repair of deteriorating concrete structures in marine environments.