千枚岩地层隧道结构劣化及全生命期服役性能诊断研究

Weakening effect of structure faces and rheological behavior of phyllite, the deterioration of tunnel structure under consideration of rheological damage effect, and the diagnosis of life cycle service performance are the key scientific issues to be addressed in the design, operation and maintenance of NATM tunnel in phyllite strata. By researching geological structural faces and rheology properties for phyllite, a rheological damage constitutive model with the anisotropy and the whole process of rheological deformation considered is established, and the rheological damage features and the micromechanical behavior are investigated. Based on the research of the time-dependent ground-support interaction effect, combined with high precision and large geometric proportion scale (1:20) rheological effect simulation experiment for tunnel in phylitte strata，the whole process of the tunnel structure failure is reconstructed, and the evolution rule of service performance for the phyllite tunnel is revealed. Furthermore, the cumulative damage and deterioration mechanism of the structure under rheological loads are to be detected; and the grade of structural deterioration of the phyllite tunnels is classified. By means of in-site test of multiple sections monitoring and big data analysis, the database with respect to the characteristics of hazard environment, tunnel structure defects and load combination is to be created, and a risk identification system for tunnel in phylitte strata is established. Through combining with the discriminant analysis method of identification system and the static parameter inversion method, a diagnosis model of service performance for the phyllite tunnel by using safety factor and crack width is established, thus the diagnosis system of life cycle service performance for the phyllite tunnel and the criteria for determining the remaining life of the structure are developed. Finally, the key techniques of life cycle service performance evaluation and degradation control of tunnel structure in phyllite strata are formed.

千枚岩结构面弱化和流变作用下隧道结构损伤劣化及全生命期服役性能诊断是穿越千枚岩地层隧道设计、运营及维护亟待解决的关键科学问题。从千枚岩构造及流变特性入手，建立表征千枚岩各向异性特征及流变全过程的流变本构模型，探明千枚岩流变损伤规律及细观力学行为。基于流变影响下围岩-支护相互作用时变效应研究，结合高精度、大比例（1:20）流变作用下围岩-结构模拟试验，再现结构由致灾诱因到性能演变至失效破坏全过程，并揭示其性能演变规律，探明流变荷载作用下混凝土结构累积损伤及劣化机制，确定结构劣化划分标准及等级。结合多断面现场健康监测及大数据分析，建立包含孕险环境、结构体缺陷和荷载作用特征数据库，搭建千枚岩隧道风险标识系统；提出标识系统识别法与静态参数反演法结合的双控双指标的结构服役性能诊断模型，建立千枚岩地层隧道全生命期服役性能诊断系统，确定隧道剩余寿命判定标准，形成千枚岩地层隧道服役性能评价及劣化控制技术。

千枚岩结构面弱化和流变作用下隧道结构损伤劣化及全生命期服役性能诊断是穿越千枚岩地层隧道设计、运营及维护亟待解决的关键科学问题。从千枚岩构造及流变特性入手，建立表征千枚岩各向异性特征及流变全过程的流变本构模型，探明千枚岩流变损伤规律及细观力学行为。基于流变影响下围岩-支护相互作用时变效应研究，结合高精度、大比例（1:20）流变作用下围岩-结构模拟试验，再现结构由致灾诱因到性能演变至失效破坏全过程，并揭示其性能演变规律，探明流变荷载作用下混凝土结构累积损伤及劣化机制，确定结构劣化划分标准及等级。结合多断面现场健康监测及大数据分析，建立包含孕险环境、结构体缺陷和荷载作用特征数据库，搭建千枚岩隧道风险标识系统；提出标识系统识别法与静态参数反演法结合的双控双指标的结构服役性能诊断模型，建立千枚岩地层隧道全生命期服役性能诊断系统，确定隧道剩余寿命判定标准，形成千枚岩地层隧道服役性能评价及劣化控制技术。