摘要
由于海底隧道服役环境中氯离子含量高,初期支护中的工字钢将不可避免产生锈蚀,导致工字钢与混凝土黏结性能下降,严重影响海底隧道支护体系的耐久性。该研究主要目的是研究锈蚀对工字钢与混凝土界面间黏结滑移行为的影响。首先对工字形型钢混凝土试件进行加速锈蚀试验和推出试验,得到试件破坏形态及黏结滑移曲线,在此基础上分析试件的黏结滑移力学性能及其过程中能量变化。试验结果表明:(1)试样的破坏模式主要为劈裂破坏,其黏结滑移曲线由三段组成:直线上升段、曲线上升段、陡降段;(2)峰值黏结强度与其对应的峰值滑移都随锈蚀率增加呈现递减趋势;(3)随着锈蚀率增加,弹性能比随着锈蚀率几乎呈现线性减小,耗散能比则反之,表明工字钢的锈速率越大,其内部损伤越严重,界面储存能量效率越低。最终,采用Weibull分布损伤统计理论得到锈蚀工字钢与混凝土界面的黏结滑移退化本构,本构模型中主要考虑了锈蚀率对τ-S曲线特征影响,本构试验曲线与理论曲线对比拟合较高,因此可应用于研究隧道工程中锈蚀工字钢与混凝土界面的黏结滑移问题。
Subjected to high chloride ion content in the service environment, corrosion of I-shaped steel in primary support of subsea tunnel is inevitable, which leads to the bond degradation of the interface between I-shaped steel and concrete and furthermore seriously affects the durability of subsea tunnel support system.The main objective of this work was to study the effect of corrosion on the bond-slip behavior of the interface between I-shaped steel and concrete.Firstly, the accelerated corrosion test and push out test were carried out on the steel reinforced concrete(SRC) specimens, and the failure mode and bond-slip curves(τ-S) were obtained.On this basis, the bond-slip mechanical properties and energy evolution during the process were analyzed.The experimental results show that:(1) The failure mode of the specimen is mainly splitting failure, and the bond-slip curve(τ-S) is composed of three stages: the linear ascending stage, the curved ascending stage, and the steep descending stage;(2) Both the peak bond strength and the corresponding peak slippage show a decreasing trend with the increase of corrosion rate;(3) With the increase of corrosion rate, the elastic energy ratio decreases linearly, while the dissipated energy ratio increases linearly, indicating that the greater the corrosion rate of I-shaped steel is, the more serious internal damage I-shaped steel shall have and the lower the energy storage efficiency of the interface shall be.Finally, the bond-slip degradation constitutive model of corroded I-shaped steel-concrete interface is obtained by using the damage statistical theory of Weibull distribution.Since the influence of corrosion rate on the τ-S curve is taken into account, and the model prediction agrees well with the test curve so that itcan be applied to the bond-slip study of corroded I-shaped steel-concrete interface.
作者
王明年
张艺腾
于丽
刘轲瑞
杨恒洪
Wang Mingnian;Zhang Yiteng;Yu Li;Liu Kerui;Yang Henghong(Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2022年第1期64-74,共11页
China Civil Engineering Journal
基金
国家自然科学基金面上项目(51878567,51878568)。
关键词
隧道工程
黏结滑移特性
损伤本构
推出试验
锈蚀工字钢
混凝土
tunnel engineering
bond-slip characteristic
damage constitutive model
push-out test
corroded I-shaped steel
concrete
