Abstract Rock mass behaviour model selection, in particular, to represent the post-failure behaviour and time-dependent behaviour of rock masses, are critical issues in the correct application of tunnelling design techniques such as the convergence-confinement method or numerical modelling. This study provides a general numerical approach for predicting longitudinal deformation profiles using a coupled ViscoElastic-ViscoPlastic Strain-Softening (VEVP-SS) model. A viscous dashpot and the strain-softening model are coupled to simulate the progressive damage process and creep failure behaviour of rock masses. Different failure criteria are considered to simulate the post-failure behaviour. As a verification step, numerical creep tests are carried out to analyse the coupled behaviour, and the basic viscoelastic and strain-softening results of the VEVP-SS model are compared with analytical solutions and numerical results. The proposed method is able to consider the coupling between post-failure behaviour and time-dependent behaviour, thus providing a new alternative method for preliminary tunnel design. Parametric analyses are then carried out to investigate the influence of different aspects on the longitudinal deformation profiles. The tunnel deformation based on the VEVP-SS model is larger than the corresponding elastic–plastic results due to the contribution of the creep behaviour, and the excavation rate becomes relevant when considering time-dependent behaviour.

中文翻译：

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应变软化时变岩体开挖隧道纵向变形剖面分析与建模

摘要 岩体行为模型选择，特别是表示岩体破坏后行为和时间相关行为的岩体行为模型，是正确应用隧道设计技术（如收敛约束法或数值建模）的关键问题。本研究提供了一种使用耦合的粘弹性-粘塑性应变-软化 (VEVP-SS) 模型预测纵向变形剖面的通用数值方法。粘性缓冲器和应变软化模型耦合以模拟岩体的渐进损伤过程和蠕变破坏行为。考虑不同的故障标准来模拟故障后的行为。作为验证步骤，进行数值蠕变试验以分析耦合行为，并将VEVP-SS模型的基本粘弹性和应变软化结果与解析解和数值结果进行了比较。所提出的方法能够考虑故障后行为和时间相关行为之间的耦合，从而为初步隧道设计提供了一种新的替代方法。然后进行参数分析以研究不同方面对纵向变形剖面的影响。由于蠕变行为的贡献，基于 VEVP-SS 模型的隧道变形大于相应的弹塑性结果，当考虑时间相关行为时，开挖速率变得相关。所提出的方法能够考虑故障后行为和时间相关行为之间的耦合，从而为初步隧道设计提供了一种新的替代方法。然后进行参数分析以研究不同方面对纵向变形剖面的影响。由于蠕变行为的贡献，基于 VEVP-SS 模型的隧道变形大于相应的弹塑性结果，当考虑时间相关行为时，开挖速率变得相关。所提出的方法能够考虑故障后行为和时间相关行为之间的耦合，从而为初步隧道设计提供了一种新的替代方法。然后进行参数分析以研究不同方面对纵向变形剖面的影响。由于蠕变行为的贡献，基于 VEVP-SS 模型的隧道变形大于相应的弹塑性结果，当考虑时间相关行为时，开挖速率变得相关。