关键词: 地铁盾构管片;氯离子传输;预测模型;杂散电流;数值模拟

Abstract: The effect of stray current on transmission performance of chloride ion into shield segment of Metro Tunnel were investigated by Matlab simulation based of the determination of chloride concentration distribution at different depths of concrete.In addition,the time dependent prediction model of chloride diffusion coefficient in concrete influencing by stray current was established by introducing the influence coefficient of stray current.The study shows that, the diffusion of chloride ions into shield segments of metro tunnels and the chloride ion content at different depths of the concrete were obviously increased after stray currents action.The relationship between the effect of stray current on the transmission performance of chloride ion into the shield segment of subway tunnel and the stray current is accorded with exponential function.The results of model calculation have a good correlation with the measured results.

Key words: subway tunnel segment;chloride ions transport;prediction model;stray current;numerical simulation