【作者】 魏晨慧；

【导师】 朱万成；

【作者基本信息】 东北大学 ， 采矿工程， 2008， 硕士

【摘要】 地下岩体工程的开挖必然在巷道周边形成开挖损伤区。开挖损伤区的形成及后续的时空演化过程是一个温度场、渗流场、应力场和损伤场相互耦合作用的过程。认清开挖损伤区的物理力学性质及其时空演化规律,对于工程稳定性和安全性评价及支护参数优化是至关重要的。针对能源深部战略储备和核废料深部地下处置等工程问题,近年来岩体开挖损伤区表征及其热(Thermal)—流(Hydraulic)—力(Mechanical)(简称为THM)耦合模型方面取得了较大的进展。考虑岩体的损伤,在THM耦合模型中引入损伤变量,提出岩体损伤过程中的THM耦合模型。借助有限元软件COMSOL Multiphysics (CM),通过有限元编程实现该模型的数值求解。通过把均匀弹性介质THM耦合响应的模拟结果与理论分析结果进行对比,证实了CM求解THM耦合方程的有效性；通过含圆形孔洞的方形岩石试样在单轴压缩条件下损伤过程的数值模拟,验证了文中提出的考虑损伤过程的THM耦合模型的正确性。开展了流固耦合环境下岩体开挖损伤区的预测研究,数值模拟表明,圆形巷道在HM耦合条件下的损伤区一方面受控于地应力条件(侧压力系数),渗流场的作用亦会对损伤区的萌生和发展产生重要的影响。最后针对核废料处置巷道所处地质环境条件,进行含裂隙岩体在温度作用下开挖损伤区的演化规律研究,数值模拟表明,裂隙的存在以及温度的作用都会对损伤区的萌生和发展产生重要的影响。更多还原

【Abstract】 The creation of an excavation damaged zone (EDZ) is expected around all man-made openings in geologic formations. The formation and its subsequent spatial and temporal evolution of EDZ, being considered as a coupled process among thermal, hydraulic mechanical, and damage fields, which is a significant issue for evaluating the engineering stability and safety, and for optimizing the supporting parameters. Recently, aiming to the study of the strategic energy storage and the radioactive waste disposal, a signficant development in EDZ characterization and coupled thermal-hydraulic-mechanical (THM) modelling has been achievend.A coupled THM model during the rock failure is proposed when the damage is considered as a key factor that controls the THM coupling. The model is solved using numerical method by programming on the base of COMSOL Multiphysics, a powerful PDE-based multiphysics modelling environment using finite element method. The proposed THM model is firstly utilized to simulate the THM response of the elastic medium and it is validated by comparing the numerical results with the analytical solutions. Secondly the proposed THM model with damage evoluation incorporated is validated by comparing the numerical results with the experimental obseravation of the failure process around circular openings under uniaxial compression.At last, the model is employed to predict EDZ under HM conditions and the numerical results indicate that, the damage zone is dominantly controlled by in-situ stess conditions, and the hydraulic pressure also has an important influence on the initiation and evolution of EDZ. At last the EDZ development of fracuted rockmass under TM conditions has been numerically simulated and the numerical results denote that both the existing fractures and the thermal effects play a important role on the initiation and evolution of EDZ.更多还原