水力耦合作用下弱胶结软岩损伤流变模型及其加固机理

Besides the characteristics of low strength and large deformation, weakly consolidated soft rock demonstrates obvious rheological characteristic and can be affected significantly by groundwater. Especially, its deformation and failure properties will be more complicated under hydro-mechanical coupling process. Further study on the damage-rheological model and reinforcement mechanism of weakly consolidated soft rock subjected to hydro-mechanical coupling will be conducted in this project with the combination methods of experimental investigation, numerical simulation and theoretical analysis. At first, conventional and rheological triaxial tests, CT test, electron microscope scanning and numerical simulation based on meso-mechanics will be conducted to study the mesostructure, hydrological characteristic and hydro-mechanical coupling mechanism of weakly consolidated soft rock, thereby the macro- and meso-damage evolution law and its aging mechanism will be revealed. Then, based on the visco-elastic,visco-plastic and damage characteristics of weakly consolidated soft rock, nonlinear viscous elastic-plastic rheological model will be established concerning the damage criterion and parameter damage law. And with the development of damage-rheological rule, nonlinear damage-rheological model reflecting the hydro-mechanical coupling will be proposed. At the meantime, corresponding nonlinear numerical analysis method will be developed by FEM software. After that, based on the nonlinear numerical analysis method above and the convergence-confinement method, numerical simulation and model tests of weakly consolidated soft rock tunnel will be conducted to reveal the coupling mechanism of surrounding rock and supporting structure. Finally, an optimum reinforcement strategy for the weakly consolidated soft rock tunnel will be obtained.

弱胶结软岩强度低、变形大、流变特征明显、受地下水影响显著，水力耦合作用下弱胶结软岩变形破坏性质异常复杂。本项目拟采用试验研究、数值模拟和理论分析相结合的手段，从宏细观角度深入研究水力耦合作用下弱胶结软岩损伤流变机理及其加固对策。进行常规-流变三轴实验、CT测试、电镜扫描和细观力学数值模拟等探究弱胶结软岩细观结构、水理特征及水力耦合作用机制，揭示水力耦合作用下弱胶结软岩损伤破坏的宏细观机理及其时效机制；基于弱胶结软岩的黏弹、黏塑和损伤变形特性，考虑损伤判别条件和参数损伤规律，建立水力耦合作用下弱胶结软岩非线性损伤流变理论模型，并基于有限元软件平台，开发相应的非线性数值模拟计算方法；基于上述数值分析程序和围岩收敛约束法，开展水力耦合作用下弱胶结软岩隧洞开挖支护模型试验和数值模拟研究，揭示弱胶结软岩隧洞围岩-支护结构耦合作用机理，形成针对弱胶结软岩的隧洞围岩加固优化设计对策和稳定性评价方法。

弱胶结软岩强度低、变形大、流变特征明显、受地下水影响显著，水力耦合作用下弱胶结软岩变形破坏性质异常复杂。本项目采用试验研究、数值模拟和理论分析相结合的手段，从宏细观角度深入研究水力耦合作用下弱胶结软岩损伤流变机理及其加固对策。揭示了水力耦合作用下弱胶结软岩损伤破坏的宏细观机理及其时效机制；建立了水力耦合作用下弱胶结软岩非线性损伤流变理论模型，并基于有限元软件平台，开发了相应的非线性数值模拟计算方法；基于上述数值分析程序和围岩收敛约束法，开展了水力耦合作用下弱胶结软岩隧洞开挖支护模型试验和数值模拟研究，揭示了弱胶结软岩隧洞围岩-支护结构耦合作用机理，形成了针对弱胶结软岩的隧洞围岩加固优化设计对策和稳定性评价方法。.项目组历经4年的合作研究，揭示了岩体水力耦合机理和损伤流变规律，建立了水力耦合作用下弱胶胶结软岩损伤流变理论模型，形成了弱胶结软岩隧洞加固优化设计对策和稳定性评价方法；建立了反映结构面水力耦合作用机制的结构面非线性蠕变本构模型；建立了水力耦合作用下锚固岩体结构面的流变本构方程及屈服强度准则；形成了复杂地质条件和工程条件下裂隙岩体围岩的时效演化理论与围岩加固安全性评价方法，依托典型工程开展了工程应用研究。相关研究成果已经获得授权国家发明专利24项；发表学术论文22，其中SCI检索10篇，检索10篇；获得山东省技术发明一等奖1项，获得教育部自然科学奖1项，获得山东省科技进步奖1项，获得中国岩石力学与工程学会技术发明一等奖1项；以科学出版社出版学术专著3部。培养毕业博士研究生1名，毕业硕士研究生6名，其中3名研究生博士毕业后在高校从事教学科研工作，2名研究生在国外攻读博士学位，2名硕士研究生参加工作并从事专业相关的实验工作。另外，5名研究生即将于2019年06月毕业获得硕士学位；有2名在读硕士研究生，正从事本课题相关研究和后续深入研究工作。