【作者】 刘晓丽；

【导师】 王思敬； 王恩志；

【作者基本信息】 清华大学 ， 水利工程， 2009， 博士

【摘要】 岩体工程规模越来越大,复杂程度越来越高,人们对岩石这一天然地质材料的认识越来越深。不同尺度的岩石(体)富含有一系列软弱结构面和裂隙,成岩作用及成岩环境的差异或随机性造成了岩石(体)宏观结构和微观结构上的非连续性、非均质性、各向异性和非线弹性(DIANE),再加上不同地应力环境及其变化,形成了岩石(体)中大量方向各异的岩石微缺陷和岩体结构面,这些微缺陷和结构面对岩体的强度和变形以及渗透性起着至关重要的作用。本文主要研究岩石(体)的多尺度特性,提取多尺度信息,并结合数值计算方法,探索从岩石到工程岩体的力学特性、水力学特性及其耦合特性。目的是为实际工程行为分析和预测提供一种更为有效、更为精细的过程模拟和过程控制手段。本文首先提出了数字岩石(体)模型的概念,将空间岩石(体)尺度分为细观尺度、实验室尺度、工程尺度和区域尺度,给出了多尺度上数字岩石(体)模型的构建方法,包括基于数字图像处理技术的细观尺度数字岩石模型的构建方法、基于随机子结构模拟的实验室尺度数字岩石模型的构建方法和基于裂隙网络模拟的大尺度数字岩体模型的构造方法。提出了虚拟岩体工程的概念,并介绍了岩体工程虚拟现实技术的理论与应用前景。在此基础上,利用有限元方法,编制了研究水岩耦合作用的计算程序GeoCAAS,对构建的各种数字岩石(体)模型进行了力学和水力学特性以及水岩耦合效应的数值试验,通过数值试验研究,探讨了岩石(体)的力学与水力学特性与其内部结构之间的关系。利用均匀化方法,推导了从细观尺度到实验室尺度的水岩耦合控制方程,揭示了细观尺度和宏观尺度上信息的融合与联系。推导了具有圆形和椭圆形含水孔洞的岩石中极限水压力值,提出了水压敏感性表征系数,用于探讨孔隙尺寸对水岩耦合效应的影响。提出了多尺度级序有限元方法(MsHFEM),并利用多尺度有限元法(MsFEM)和MsHFEM研究了非均质岩石中的渗流过程。更多还原

【Abstract】 With the rock engineering scale larger and larger, and its complexity higher and higher, people’s cognition to geological materials is more and more deep. Rock or rock mass is a kind of natural geological body which is rich in weak structure planes and fractures. The differences or the randomicity of its diagenesis and diagenetic environment lead to the discontinuous, inhomogeneous, anisotropic and non-elastic (DIANE) characters of rock masses in their macrostructures and microstructures. In addition, combined with different ground stress environment and its change, abundant rock mass structure planes with different directions are formed, which affects the deformation and seepage process and the strength of rock and rock mass. Multiscale properties of rock or rock mass are studied in this thesis. By extracting the multiscale information and combining them with numerical methods, the mechanical and hydraulic and their coupling properties are discussed from rock to engineering rock mass. The main purpose is to provide a more effective and finer method for behavior analysis and predicting of real engineering.The concept of digital rock or rock mass models is put forward firstly. The special rock or rock mass scale is divided to be meso-scale, lab-scale, engineering-scale and regional scale, and the modelling methods, including the meso-scale digital rock modeling based on the digital image process, the lab-scale digital rock modeling by random sub-structure simulation method and the large scale digital rock mass modeling by random fracture networks simulation method are given. Many inhomogeneous digital rock or rock mass models containing different sub-structures are modeling according to the various shape of natural engineering rock or rock mass. In addition, the concept of virtual rock engineering is presented, and the theory of rock mass virtual reality and its application are introduced.On the basis that have been mentioned, FEM-based computer codes, GeoCAAS (Geo Computer Aided Analysis System), are developed to study the mechanics, hydraulics, and the coupled process between them with the various digital rock or rock mass models. The relationship between mechanics and hydraulics properties of rock or rock mass and the sub-structures is discussed.The homogenization method is utilized to deduce the control equations of rock-water coupled process from meso-scale to lab-scale. The syncretization and relationship of the information between these two scales are revealed.The ultimate water pressure in rocks with circular and elliptic holes is deduced, and water pressure sensitivity characterizing coefficient is defined to discuss the influence of holes’scale on the water-rock coupled process. The multi-scale hierarchy finite element method (MsHFEM) is provided for multiscale probloms in rock engineering, and the multi-scale finite element method (MsFEM) and MsHFEM are applied to study the seepage process in heterogeneous rock mass.更多还原