基于微分等价递归算法的桥梁体系耐久性可靠度动态评估

结构耐久性可靠度评估应以体系为对象，并且要体现结构性能的自身特征及动态时变特性。基于贝叶斯动态更新技术，以混凝土碳化深度为随机变量，利用体现结构个性特征的实桥检测信息对传统静态碳化模型进行修正。以可靠度指标为评价标准，引入能计入构件间相关性的微分等价递归算法，并将其嵌入到贝叶斯动态更新框架中，构造出体系碳化耐久性动态评估模型和计算流程，形成了复杂体系碳化耐久性动态可靠度计算方法，采用MATLAB平台开发了计算程序。利用碳化试验模拟实桥检测数据，对钢筋混凝土拱桥进行了体系动态耐久性评估，发现模型更新后拱圈和立柱的碳化耐久性可靠度比更新前有所增大，而桥面板则有所降低，体系耐久性可靠度低于构件可靠度。

Dynamic evaluation on durability reliability of bridge system based on differential equivalent recursive algorithm

Structural durability reliability assessment should be based on the system and should also reflect the characteristics of the structural properties and dynamic time-varying characteristics. In this paper, based on Bayesian dynamic updating, taking the depth of concrete carbonization as a random variable, the traditional static carbonization model is modified based on the real bridge detection information that reflects the structural personality characteristics. Taking the reliability index as the evaluation standard, a differential equivalent recursive algorithm that can be included in the correlation between components is introduced and embedded in the Bayesian dynamic update framework. The dynamic evaluation model and calculation process of carbonization durability of the system are proposed, and the dynamic reliability calculation method of carbonization durability of complex system is put forward. The calculation program is developed based on MATLAB platform. The dynamic durability evaluation of the reinforced concrete arch bridge was carried out by carbonation simulation tests. Results show that the reliability of carbonization durability of the arch ring and the column increased while the reliability of carbonization durability of bridge deck decreased via the modified model. The durability of the system is lower than the reliability of the component.