论文部分内容阅读
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。
Corrosion environment of shield tunnel steel bar corrosion seriously affect the long-term safety and durability of the tunnel structure. In view of this situation, by numerical simulation, by considering the time effect, to explore the corrosion rules of the steel bar in the 100-year service life of shield tunnel under different environmental conditions, the conclusions are: With the extension of the tunnel service time, The concentration of ions accumulated on the surface of steel bar keeps increasing, but the maximum concentration of ions accumulated in different locations is different. The closer the concentration of ions is to the joint surface, the bigger the water pressure outside the joint is. The corrosion time is shorter; the concentration of chloride ion on the outer surface of the slice also affects the ion concentration at the location of the rebar; the larger the value is, the higher the maximum ion concentration accumulated at the same location of the rebar is and the shorter the corrosion time appears; It is an effective way to delay the thickness of shield lining to reach the critical concentration of corrosion and to ensure the safety of the tunnel structure in the corrosive environment.