Corrosion of I-shaped steel in the primary support of the subsea tunnel is inevitable due to high chloride ion content, which will weaken the bond performance between concrete and I-shaped steel, resulting in a reduction in the service time of the subsea tunnel. Based on Xiang'an subsea tunnel, the bond–slip behavior between concrete and corroded I-shaped steel was studied by the accelerated corrosion tests and push-out tests, the experimental results indicated that: (1) The cracks of experimental specimens could be divided into two main forms: splitting failure (corrosion rate less than 5.79%); spalling failure (corrosion rate more than 5.79%). (2) A three-stage bond-slip law for concrete and corroded I-shaped steel was proposed, and the formulae for calculating the bond strength were established. Furthermore, the degradation process of bond-slip caused by corrosion was analyzed by energy principle and damage mechanics. Based on energy principle, it found that the elastic energy stored in the interface increased before the peak point of bond-slip curve and decreased after the peak point, while the dissipated energy in the interface always increased with slip value. Finally, the interface relative damage variable was defined based on secant line anti-sliding modulus and slip equivalent principle. The interface damage development process can be divided into three stages: initial damage, rapid damage development, and slow damage accumulation.

中文翻译：

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混凝土与锈蚀工字钢黏结滑移行为试验研究及力学分析

由于氯离子含量高，工字钢在海底隧道初级支护处的腐蚀是不可避免的，这会削弱混凝土与工字钢之间的粘结性能，导致海底隧道的服役时间减少。以翔安海底隧道为例，通过加速腐蚀试验和顶出试验研究混凝土与锈蚀工字钢之间的粘结滑移行为，试验结果表明：（1）试验试件的裂缝可分为两种主要形式：劈裂失效（腐蚀率小于5.79%）；剥落失效（腐蚀率大于5.79%）。(2)提出了混凝土与锈蚀工字钢的三级粘结滑移规律，并建立了粘结强度计算公式。此外，结合能量原理和损伤力学分析了腐蚀引起的粘结滑移退化过程。根据能量原理，发现界面储存的弹性能在键滑曲线峰点之前增加，在峰点之后减小，而界面耗散的能量总是随着滑移值的增加而增加。最后，基于割线抗滑模量和滑移等效原理定义了界面相对损伤变量。界面损伤发展过程可分为初始损伤、快速损伤发展和缓慢损伤积累三个阶段。发现界面储存的弹性能在键滑曲线峰点之前增加，在峰点之后减小，而界面中的耗散能量总是随着滑移值的增加而增加。最后，基于割线抗滑模量和滑移等效原理定义了界面相对损伤变量。界面损伤发展过程可分为初始损伤、快速损伤发展和缓慢损伤积累三个阶段。发现界面储存的弹性能在键滑曲线峰点之前增加，在峰点之后减小，而界面中的耗散能量总是随着滑移值的增加而增加。最后，基于割线抗滑模量和滑移等效原理定义了界面相对损伤变量。界面损伤发展过程可分为初始损伤、快速损伤发展和缓慢损伤积累三个阶段。