侵蚀环境和荷载耦合作用下盾构管片氯离子扩散规律试验研究  

Experimental Study on the Diffusion Law of the Chloride Ion in a Shield Segment Under Coupled Erosion and Load

作　　者：雷明锋[1,2] 彭立敏[1] 谢友均[1] 谭立新 彭斌 

机构地区：[1]中南大学土木工程学院,长沙410075 [2]中国建筑第五工程局有限公司,长沙410004

出　　处：《现代隧道技术》2014年第3期98-104,共7页Modern Tunnelling Technology

基　　金：国家重点基础研究发展计划资助项目(973:2011CB013802);国家自然科学基金高铁联合基金重点项目(U1134208);国家自然科学基金资助项目(50808176);中国建筑第五工程局有限公司项目

摘　　要：文章针对盾构隧道赋存环境及结构受力特点,构建了氯盐侵蚀环境和结构荷载耦合作用下的盾构管片结构单侧一维侵蚀试验方法;研发完成了相应的人工环境模拟试验装置,并进行了侵蚀试验;探讨了侵蚀环境氯离子浓度、侵蚀时间和荷载水平对氯离子入侵及其含量分布规律的影响。结果表明:随着环境中氯离子浓度的提高以及侵蚀时间的延长,混凝土保护层中的氯离子含量逐渐增加;同时,外荷载的存在改变了结构混凝土内部的孔隙特征,直接影响了氯离子的入侵,表现为拉应力有利于氯离子入侵,而压应力则相反。Aimed at the environmental and mechanical characteristics of shield-driven tunnels, this paper establishes a 1D unilateral erosion test method for segments under the combined influence of chloride erosion and structural load and presents the results of tests conducted using a test device that was developed in a simulated environment. Furthermore, it discusses the influence of chloride ion concentration, erosion time, and load level on chloride ion diffusion and content distribution. The results show that the chloride ion content in the concrete cover increases gradually with the increase of chloride ion concentration and erosion time; the pore characteristics inside the concrete are changed by external loading, which directly affects the chloride ion penetration, manifesting in the fact that penetration is easier under tensile stress rather than compressive stress.

关 键 词：盾构管片 氯盐环境 结构荷载 耦合作用 扩散规律 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]