This paper presents a numerical approach to study the damage evolution of secondary tunnel lining under the combined actions of corrosion of the preliminary support and the creep deformation of the surrounding rock. This improved numerical approach contains three main models for: (1) tensile failure of corroding rock bolt; (2) yielding of corroding supporting steel arch; and (3) elastoplastic damage of secondary tunnel lining. The corroded rock bolt's failure criterion under tension, the yield criterion of a corroded steel arch under combined compression and bending actions were developed and programmed using FLAC3D's FISH language programming. For the secondary lining failure, a Mohr-Coulomb criterion with a damage formulation based on a statistical damage distribution model was adopted. The validity of the models was verified, and the mechanical response of the supporting structures was investigated. The results showed that: (1) a combined strength envelop can reasonably simulate the mechanical behavior of the steel arch under pure compression, pure bending, and compression-bending action; (2) the corrosion fracture criterion of the rock bolt can adequately reflect rock bolt axial force development process of nonlinear increase and decrease, and failure with the increase of axial strain; (3) damage of concrete can be adequately described by the damage constitutive model, with the damage parameters exerting a strong influence on the post-peak behavior of concrete; and (4) the damage level of the plastic zone at the same location in secondary lining for the corrosion yield model is larger than that predicted from the original FLAC^3D structural models.

本文提出了一种数值方法，研究在初步支护腐蚀和围岩蠕变变形的共同作用下，二次隧道衬砌的破坏演化。这种改进的数值方法包含以下三个主要模型：（1）腐蚀岩栓的拉伸破坏；（2）腐蚀支撑钢拱的屈服；（3）二次隧道衬砌的弹塑性破坏。使用FLAC3D的FISH语言编程开发并编程了受拉腐蚀的岩石锚杆在拉伸下的破坏准则，受腐蚀的钢拱在组合的压缩和弯曲作用下的屈服准则。对于二次衬砌破坏，采用了基于统计损伤分布模型的损伤公式的Mohr-Coulomb准则。验证了模型的有效性，并研究了支撑结构的机械响应。结果表明：（1）组合强度包络可以合理地模拟钢拱在纯压缩，纯弯曲和压弯作用下的力学行为；（2）锚杆的腐蚀破坏准则可以充分反映锚杆轴向力发展过程的非线性增加和减小，以及随着轴向应变的增加而破坏。（3）可以用损伤本构模型充分描述混凝土的损伤，损伤参数对混凝土的峰后行为有很大的影响。（4）对于腐蚀屈服模型，次生衬里相同位置的塑性区的破坏程度大于原始FLAC所预测的程度^3D结构模型。