基于贝叶斯修正的锈蚀RC结构保护层开裂时间预测  

Prediction of cracking time of concrete cover in corroded reinforced concrete structures based on Bayesian updating

作　　者：黄天立[1] 李群 陈龙 陈华鹏 阳波 何益斌 HUANG Tianli;LI Qun;CHEN Long;CHEN Huapeng;YANG Bo;HE Yibin(School of Civil Engineering,Central South University,Changsha 410075,China;School of Transportation Engineering,East China Jiaotong University,Nanchang 330013,China;Hunan Architectural Design Institute Group Co.Ltd.,Changsha 410012,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]华东交通大学交通运输工程学院,江西南昌330013 [3]湖南省建筑设计院集团股份有限公司,湖南长沙410012

出　　处：《中南大学学报(自然科学版)》2025年第2期575-585,共11页Journal of Central South University:Science and Technology

基　　金：江西省重点研发计划“揭榜挂帅”项目(20223BBH80002);长沙市科技计划重大专项(kh2401024)。

摘　　要：腐蚀电流密度的测量存在误差,且物理模型预测腐蚀电流密度时具有较大的不确定性。为了量化物理模型的不确定性,准确预测钢筋非均匀锈蚀引起的钢筋混凝土(RC)结构保护层开裂时间,提出一种基于贝叶斯修正的锈蚀RC结构保护层开裂时间预测方法。首先,采用贝叶斯方法结合实测数据推断RC结构腐蚀开裂过程中的腐蚀电流密度物理模型中的参数,采用马尔科夫蒙特卡罗方法中的Metropolis-Hastings算法进行采样,得到参数的后验分布;然后,利用后验分布传递参数的不确定性,得到腐蚀电流密度预测模型;最后,利用锈蚀产物质量相等将非均匀腐蚀的钢筋锈蚀椭圆模型转换成均匀腐蚀的厚壁圆筒模型来计算混凝土保护层中的应力,通过钢筋损失量与腐蚀电流密度预测值之间的关系,预测混凝土保护层开裂时间。通过2个试验试件验证所提方法预测锈蚀RC结构保护层开裂时间的有效性。研究结果表明:基于贝叶斯修正后的腐蚀电流密度预测模型能准确地预测腐蚀电流密度,且能够有效地预测锈蚀RC结构保护层开裂时间,开裂时间的预测值与实测值之间的相对误差小于5%。Due to the measurement errors in corrosion current density and the significant uncertainty in predicting corrosion current density by using physical models,in order to quantify the uncertainty of the physical model and accurately predict the cracking time of concrete cover in corroded reinforced concrete(RC)structures caused by uneven corrosion of rebars,a prediction method for the cracking time of concrete cover in corroded RC structures by using Bayesian updating was proposed.Firstly,the Bayesian method was used to infer the parameters of the corrosion current density physical model during the corrosion cracking process of RC structures combined with experimental results.The Metropolis-Hastings algorithm in the Markov Chain Monte Carlo method was used for sampling to obtain the posterior distribution of the parameters.Then,utilizing the posterior distribution to propagate the uncertainty of the parameters,a corrosion current density prediction model was obtained.Finally,using the equivalence of the mass of rust products,the non-uniform corrosion model of the rebar was transformed into a uniformly corroded thick-walled cylindrical model to calculate the stress distribution in the concrete cover.The cracking time of the concrete cover was predicted through the relationship between the amount of rebar loss and the predicted value of the corrosion current density.The effectiveness of the proposed method in predicting the cracking time of concrete cover in corroded RC structures was validated by using two test specimens.The results indicate that the corrosion current density prediction model based on Bayesian updating can effectively predict the magnitude of the corrosion current density,and it can predict the cracking time of cover in corroded RC structure effectively.The error between the predicted crack initiation time and the measured value is less than 5%.

关 键 词：锈蚀钢筋混凝土结构 保护层开裂 开裂时间 非均匀锈蚀 贝叶斯方法 

分 类 号：TU375[建筑科学—结构工程]