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针对海水腐蚀板岩蠕变研究缺乏的现状,以大连地铁板岩为对象,开展Na Cl溶液腐蚀蠕变试验和模型的研究。首先进行板岩的Na Cl溶液浸泡试验,从细观角度,通过SEM电镜扫描图像和EDS能谱元素的对比,并结合纵波波速和p H值分析,揭示不同浸泡时间板岩试件腐蚀特性。然后通过RLW–2000岩石力学三轴流变系统开展蠕变试验,从宏观角度分析不同腐蚀条件下试件瞬时变形、初始段、稳定段和加速段的蠕变曲线和特征。总结长期强度、蠕变速率、弹性模量随浸泡时间的变化规律。最后基于试验结果,提出考虑化学损伤的五元件非线性黏弹塑性蠕变模型(H|M-CD模型),并利用1st Opt优化软件对模型参数进行辨识。研究结果表明,Na Cl溶液的腐蚀作用改变了板岩的蠕变力学特性,随着浸泡时间的增加,加速段速率增大,蠕变时间缩短。浸泡时间越长,破坏特征越明显。模型理论曲线与试验曲线在3个阶段吻合较好,说明所提出的H|M-CD模型可准确描述腐蚀板岩蠕变全过程。研究结果为板岩岩石工程在海水环境中的长期稳定性评价提供了参考和依据。
Aiming at the lack of research on the creep of seawater-corroded slate, the corrosion creep test and model of NaCl solution were carried out based on Dalian metro slate. Firstly, the silage NaC solution immersion test was carried out. From the microscopic point of view, SEM images and EDS spectral elements were compared. Combined with the longitudinal wave velocity and p H value analysis, the corrosion characteristics of slate samples with different immersion time were revealed. Then the creep test was carried out by RLW-2000 rock mechanics triaxial rheology system. The creep curves and characteristics of instantaneous deformation, initial section, steady section and acceleration section under different corrosion conditions were analyzed macroscopically. The long-term strength, creep rate and elastic modulus change with immersion time are summarized. Finally, based on the experimental results, a five-element nonlinear viscoelastic-plastic creep model (H | M-CD model) considering chemical damage was proposed and the parameters of the model were identified by 1st Opt optimization software. The results show that the corrosion of NaCl solution changes the creep mechanical properties of slate. With the increase of immersion time, the velocity of acceleration section increases and the creep time shortens. The longer the immersion time, the more obvious the damage characteristics. The model theoretical curve and experimental curve agree well in three stages, which shows that the proposed H | M-CD model can accurately describe the whole process of corrosion slate creep. The results provide a reference and basis for the long-term stability evaluation of slate rock engineering in seawater environment.