基于探地雷达的杂散电流环境下混凝土损伤检测研究  

Research On Concrete Damage Detection under Stray Current Environment Based on Ground Penetrating Radar

作　　者：蔡智超[1,2,3] 虞一孺 张敬 Cai Zhichao;Yu Yiru;Zhang Jing(State Key Laboratory of Rail Transit Infrastructure Performance Testing and Guarantee East China Jiaotong University,Nanchang 330013 China;School of Electrical and Automation Engineering East China Jiaotong University,Nanchang 330013 China;State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology,Tianjin 300130 China)

机构地区：[1]华东交通大学轨道交通基础设施性能检测与保障国家重点实验室,南昌330013 [2]华东交通大学电气与自动化工程学院,南昌330013 [3]省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学),天津300130

出　　处：《电工技术学报》2024年第21期6636-6646,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金青年科学基金(51807065);省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学)开放课题基金(EERI_KF2021007);江西省自然科学基金面上项目(20224BAB204053);江西省自然科学基金重点项目(2021ACB20404)资助。

摘　　要：因走行轨不能对地完全绝缘,地铁运行时会产生杂散电流,导致混凝土中的钢筋发生电化学腐蚀。由于电化学腐蚀的持续发生,腐蚀产物累积在钢筋表面周围,从而对混凝土产生膨胀应力,导致混凝土开裂脱落,因此有必要对杂散电流影响严重区域的钢筋混凝土结构进行检测。该文首先基于多物理场法对钢筋混凝土的电化学腐蚀进行二维瞬态仿真研究,得到与实际混凝土结构相近似的腐蚀损伤图;进而对得到的损伤图进行探地雷达数值正演模拟检测。研究结果表明,在钢筋混凝土发生电化学腐蚀的过程中,钢筋直径的减小和腐蚀产物厚度的增加对探地雷达检测信号影响较小,因膨胀应力而产生的混凝土裂缝对探地雷达检测信号的影响起主要作用。Due to the incomplete insulation of the running rail to the ground,stray current leakage occurs during subway operation,which leads to electrochemical corrosion of reinforced concrete structure along the subway.The purpose of this study is to study the electrochemical corrosion of steel bars and the evolution of concrete damage caused by stray current,and to detect cracks caused by corrosion damage of reinforced concrete by ground penetrating radar(GPR).Firstly,a two-dimensional reinforced concrete model was established.Then,in order to more realistically simulate the evolution of cracks in reinforced concrete due to reinforcement corrosion,a tertiary current distribution,Nernst-Plank interface,is added to simulate electrochemical corrosion of reinforcement induced by external oxygen,in which oxygen diffuses from the left surface of the concrete to the interior.At the same time,solid mechanics physical field is added to simulate the strain of reinforcement and concrete due to reinforcement corrosion.Secondly,based on the multi-physics method,the two-dimensional transient simulation of the electrochemical corrosion process of reinforced concrete is studied,and the approximate actual corrosion damage map of reinforced concrete structure under different service times is obtained.Then,the obtained damage map was transformed by gray scale,and the corresponding electrical parameters(relative permeability,conductivity and relative permeability)were assigned to different media regions(concrete,steel bars and cracks)in the damage map.Finally,based on the ground penetrating radar numerical forward simulation method,the damage map after gray level change was simulated by A-scan and B-scan.The evolution of concrete damage caused by electrochemical corrosion of rebar during 0~3800 days in service time was studied.Only when the expansion stress generated by the corrosion products is greater than the tensile strength of the concrete,the cracks will appear in the concrete around the rebar and gradually expand to the surrounding

关 键 词：杂散电流 电化学腐蚀损伤 探地雷达 时域有限差分法 

分 类 号：TH878[机械工程—仪器科学与技术] P631[机械工程—精密仪器及机械] TM15[天文地球—地质矿产勘探]