Understanding the time-dependent behavior of rocks has long been a critical challenge, hindered by complex multiscale failure mechanisms and time effects. Prolonged exposure to environmental factors such as groundwater and corrosive ions causes significant time-dependent behavior in the surrounding rock, posing potential risks to tunnel safety. In this study, the discrete element method was adopted to investigate the influence of environmental erosion on the time-dependent performance of rocks and mechanical response of tunnel linings at the structural level. To simulate rock erosion, an inhomogeneous erosion parallel bond model (IEPBM) was proposed, conceptualizing the erosion process as the gradual dissolution of bonding cementation between microscopic structures. The Weibull function was introduced to represent the inhomogeneous erosion of rock materials. The IEPBM was validated by comparing the simulation results with indoor tests, confirming the model’s reliability. The model incorporated an updated bonding radius multiplier to simulate microstructural changes during erosion. Subsequently, the effects of the erosion degree, erosion rate, and inhomogeneity on the time-dependent mechanical behavior of the rock were explored. The results indicated that the creep behavior induced by environmental erosion was a macroscopic deformation process, with rock failure resulting from the accumulation of microscopic damage. The model successfully captured three creep stages: attenuation, stability, and acceleration. Additionally, erosion degree and rate significantly affected the multiscale creep properties of rocks, with highly inhomogeneous rocks potentially failing after relatively minor erosion. Finally, the time-dependent mechanical response of the tunnel lining owing to surrounding rock erosion was analyzed at the structural level. The erosion of the surrounding rock increases the stress on the lining, compromising the long-term safety of the tunnel structure and contributing to lining failures observed in modern tunnels.

中文翻译：

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研究环境侵蚀引起的岩石的时间依赖性行为及其对隧道衬砌长期安全的影响


长期以来，了解岩石的时间依赖性行为一直是一项关键挑战，受到复杂的多尺度破坏机制和时间效应的阻碍。长时间暴露于地下水和腐蚀性离子等环境因素会导致周围岩石出现明显的时间依赖性行为，从而对隧道安全构成潜在风险。本研究采用离散元方法，在结构层面研究了环境侵蚀对岩石时变性能和隧道衬砌力学响应的影响。为了模拟岩石侵蚀，提出了一种非均匀侵蚀平行粘合模型 （IEPBM），将侵蚀过程概念化为微观结构之间粘合胶结的逐渐溶解。引入 Weibull 函数来表示岩石材料的不均匀侵蚀。通过将仿真结果与室内测试进行比较来验证 IEPBM，证实了模型的可靠性。该模型结合了更新的粘合半径乘数，以模拟侵蚀过程中的微观结构变化。随后，探讨了侵蚀程度、侵蚀速率和不均匀性对岩石随时间变化的力学行为的影响。结果表明：环境侵蚀引起的蠕变行为是一个宏观变形过程，岩石破坏是由微观损伤的积累引起的。该模型成功捕获了三个蠕变阶段：衰减、稳定性和加速度。此外，侵蚀程度和侵蚀速率显著影响岩石的多尺度蠕变特性，高度不均匀的岩石在相对较小的侵蚀后可能会失效。 最后，在结构层面分析了隧道衬砌由于围岩侵蚀而引起的随时间变化的机械响应。围岩的侵蚀增加了衬砌的应力，损害了隧道结构的长期安全性，并导致现代隧道中出现衬砌失效。