腐蚀环境下盾构隧道管片钢筋锈蚀规律研究

发布时间：2018-03-09 04:03

本文选题：腐蚀环境　切入点：盾构隧道　出处：《公路》2017年09期 　论文类型：期刊论文

【摘要】：腐蚀环境下盾构隧道管片钢筋锈蚀严重影响隧道结构的长期安全使用性及耐久性。针对这一现状,采用数值模拟的方式,通过考虑时间效应,探究在不同环境条件下盾构隧道100年服役期内管片钢筋锈蚀规律,得到的结论主要有:随着隧道服役时间的延长,钢筋表面累积的离子浓度不断变大,但不同位置处累积的最大离子浓度不同,越靠近接缝面位置处离子浓度越大;管片外侧水压越大,钢筋同一位置处累积的离子浓度越大,出现锈蚀的时间越短;改变管片外侧表面氯离子浓度同样会影响钢筋位置处离子浓度,其值越大,钢筋同一位置处累积的最大离子浓度越高,出现锈蚀的时间越短;提高腐蚀环境中盾构隧道管片衬砌保护层厚度,是延缓钢筋位置达到锈蚀临界浓度时间以及保障隧道结构安全承载的有效手段。
[Abstract]:The corrosion of steel bar in shield tunnel segment seriously affects the long-term safety and durability of tunnel structure. In view of this situation, numerical simulation method is adopted and time effect is considered. The corrosion rule of steel bars in shield tunnel during its 100-year service life is investigated. The main conclusions are as follows: with the extension of tunnel service time, the accumulated ion concentration on the surface of reinforcement becomes larger and larger. However, the maximum ion concentration at different positions is different, the higher the ion concentration is near the joint surface, the larger the water pressure outside the segment is, the greater the accumulated ion concentration is at the same position of the steel bar, and the shorter the corrosion time is. Changing the chloride ion concentration on the outside surface of the segment will also affect the ion concentration at the steel bar position. The larger the ion concentration is, the higher the maximum ion concentration accumulated at the same position of the steel bar, and the shorter the corrosion time is. Increasing the thickness of shield tunnel segment lining in corrosive environment is an effective means to delay the steel bar position to reach the critical corrosion concentration time and to ensure the safe bearing of tunnel structure.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;
【分类号】：U455.43

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