地铁杂散电流对隧道钢筋极化电位分布影响研究  

Study on the Influence of Metro Stray Current on Polarization Potential Distribution of Tunnel Reinforcement

作　　者：钱根 王沛沛 湛博 QIAN Gen;WANG Peipei;ZHAN Bo(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道标准设计》2023年第11期200-206,共7页Railway Standard Design

基　　金：中铁第四勘察设计院集团有限公司科技研究开发计划项目(2022K002)。

摘　　要：地铁直流牵引系统产生的杂散电流泄漏及腐蚀危险已成为城市轨道交通建设规划关心的问题,隧道结构钢筋由于其相对钢轨位置不同,杂散电流影响也将呈现出不同的模式,研究不同工况下地铁杂散电流对隧道结构的影响特性,对于改善杂散电流防护工程措施,提高隧道结构钢筋耐腐蚀寿命具有重要意义。建立地铁杂散电流对隧道结构钢筋极化电位分布影响实验模型,针对存在邻近金属管线、隧道钢筋横联及加装排流网等情况,开展隧道结构钢筋沿线极化电位分布测试。结果表明,邻近金属管线虽自身受到明显杂散电流影响,但其存在对隧道各结构钢筋上的极化电位分布几乎没有影响;隧道结构钢筋并联,能有效降低杂散电流对隧道顶部结构钢筋的影响,阳极极化与阴极极化程度较并联前分别下降约14.1%与26.3%,对靠近钢轨附近结构钢筋影响不大;排流网使靠近钢轨和排流网的结构钢筋平均极化程度增加约28.3%,对远离排流网的金属结构,排流网能有效降低杂散电流影响;杂散电流流通路径对结构钢筋极化电位分布有明显影响,结构钢筋沿线极化程度随着钢轨与结构钢筋距离的增加呈指数衰减。Stray current leakage and corrosion risk caused by Metro system have become the concerns of urban rail transit construction planning.Stray current will show different influence features due to the different structure relative position.Studying the influence of metro stray current on tunnel structure under different operation situations is of great significance to improve stray current protection methods and the corrosion resistance life of metal structure.In this paper,an experimental model of tunnel structures is established.The existence of adjacent metal pipelines and stray current collection grid,and the interconnection of tunnel reinforcement have been considered.Results show that although the adjacent metal pipeline itself is obviously affected by stray current,its existence has little effect on the polarization potential distribution on the structural reinforcement of the tunnel.The interconnection of tunnel structural reinforcement can effectively reduce the influence of stray current on the structural reinforcement at the top of the tunnel.Compared with that before interconnection,anode polarization and cathode polarization are reduced by about 14.1% and 26.3% respectively.The interconnection has little effect on the structural reinforcement near the rail.The existence of stray current collection grid will increase the average polarization degree of structural reinforcement near the rail by about 28.3%.For the metal structure far away from the rail,the influence can be effectively reduced.The stray current flow path has an obvious effect on the polarization potential distribution.The polarization degree along the structural reinforcement decreases exponentially with the increase of the distance between the rail and the structural reinforcement.

关 键 词：城市轨道交通 杂散电流 隧道 结构钢筋 极化电位 腐蚀 

分 类 号：U231[交通运输工程—道路与铁道工程] U45[建筑科学—桥梁与隧道工程]