节理岩体宏观变形特性研究及工程应用
发布时间：2018-10-16 11:51
【摘要】：结构面控制着岩石地基、岩石边坡和地下洞室围岩的变形与稳定,是岩体力学性质复杂性的根源。由于结构面密集且分布不均匀、结构面之间相互交错以及空间分布的随机性,使得节理岩体变形特性表现出显著的非均匀性、各向异性、尺寸效应和随机效应。深入研究节理岩体的变形特性,对充分利用岩体、有针对性的加固岩体具有重要的理论和工程意义。目前获取节理岩体变形参数的手段主要有工程经验法、现场试验法、解析法和数值试验法。国内外学者对节理岩体的变形特性做了很多研究,但仍然存在以下不足：(a)解析法能很好的解释规则且贯穿性节理的变形特性,但缺乏对非贯穿节理变形机理的合理模拟；(b)三维结构面网络模型的离散存在较大难度,所以基于三维结构面网络离散模拟的成果较少,更缺乏对三维等效参数的随机性分析；(c)数值试验方法高效,但缺乏与岩体现场变形试验结果的对比和验证；(d)节理岩体各向异性对水工结构,特别是对高拱坝-坝基系统工作状态的影响研究鲜有报道。本文针对这些主要问题,采用理论分析、室内外试验、数值模拟与工程经验相结合的方法,从以下几个方面展开研究：(1)节理岩体变形的各向异性。对于规则贯穿节理岩体,基于应变叠加原理,推导了等效弹性本构,并分析了几种特殊贯穿节理岩体变形的空间特性。结果表明,层状节理岩体变形特性在空间上关于节理法线方向轴对称,柱状节理岩体变形特性在空间上关于平面对称,含三组正交节理的岩体特性在空间上关于平面对称。通过非贯穿节理岩体的精细模拟,验证了岩桥具有钉梢和抗剪的作用,并基于应变叠加原理、应力一致原则、应力分担原则以及应变一致原则,引入岩桥影响高度的概念,推导了节理岩体的变形等效本构关系。(2)节理岩体变形的随机效应。本文借助蒙特卡洛方法,生成了具有代表性的结构面网络样本,基于复合单元法,建立了三维柔度张量的数值试验方法,以SW水电站的复杂节理岩体为研究对象,对岩体三维柔度张量的各个分量进行统计分析,探讨节理岩体变形参数的随机特性。结果表明,每组结构面网络样本的三维等效柔度张量由于结构面的分布不同而不同,但是各个分量均服从一定的统计规律。以SW水电站左岸弱风化节理岩体为例,其三维柔度张量最接近服从对数正态分布。(3)基于岩体现场变形试验的结构面参数反演和区域岩体等效柔度张量的预测。利用岩体现场变形试验的结果,结合结构面地质调查、岩石室内试验,采用结构面网络离散模拟的数值试验法对结构面以法刚切刚为主控的变形参数进行反演,获得试验点位置的等效柔度张量并预测区域岩体的等效柔度张量。用反演得到的柔度张量进行刚性承压板试验验证,证明了反演结果的可靠性。(4)拱坝坝基岩体多尺度结构面的数值分析模型。该模型结合等效模拟和离散模拟的优势,既可以考虑断层等定位结构面,也可以考虑Ⅳ级和Ⅴ级随机结构面,并成功运用于QBT水电站拱坝-坝基系统的变形分析。结果表明：当考虑随机结构面造成的各向异性特性时,该拱坝及坝肩岩体位移分布发生了变化,坝肩岩体顺河向位移减小,拱端位移夹角增大,拱坝坝肩稳定条件变好；但拱坝变形更加扁平化,拱坝应力变坏,需要引起注意。本文研究成果对于节理岩体变形规律研究、参数合理化取值及水工结构稳定分析评价具有重要意义。
[Abstract]:The structural surface controls the deformation and stability of rock foundation, rock slope and surrounding rock of underground cavity, and is the source of the complexity of mechanical properties of rock mass. The deformation characteristics of jointed rock mass show remarkable non-uniformity, anisotropy, size effect and random effect because of the dense and uneven distribution of the structure surface and the randomness of the spatial distribution between the structural planes. In depth study of the deformation characteristics of jointed rock mass, it has important theoretical and engineering significance for making full use of rock mass and targeted reinforcing rock mass. At present, the means of obtaining the deformation parameters of jointed rock mass mainly include engineering experience method, field test method, analytical method and numerical test method. The deformation characteristics of jointed rock mass have been studied by scholars both at home and abroad. However, the following shortages still exist: (a) the analytical method can well explain the deformation characteristics of the regular and penetrating joints, but lack reasonable simulation of the non-penetrating joint deformation mechanism; (b) the discrete existence of the three-dimensional structural plane network model is more difficult, so that the results of discrete simulation based on the three-dimensional structural plane network are less, and the randomness analysis of the three-dimensional equivalent parameter is more lacked; and (c) the numerical test method is high-efficiency, However, the comparison and verification of the results of field deformation test of rock mass are lacking, and (d) the influence of the anisotropy of jointed rock mass on hydraulic structure, especially on the working state of high arch dam-dam foundation system is seldom reported. In view of these main problems, the paper adopts the method of theoretical analysis, indoor and outdoor test, numerical simulation and engineering experience, and studies the following aspects: (1) anisotropy of joint rock mass deformation. On the basis of the principle of strain superposition, the equivalent elastic structure is derived for regular penetration of jointed rock mass, and the spatial characteristics of several special penetrating jointed rock mass deformation are analyzed. The results show that the deformation characteristics of the layered jointed rock mass are symmetric in the direction of the normal direction of the joint, the deformation characteristics of the columnar joint rock mass are symmetric about the plane in space, and the rock mass properties of the three groups of orthogonal joints are spatially symmetrical about the plane. Through the fine simulation of non-penetrating jointed rock mass, it is verified that the rock bridge has the function of nail tip and shear, and based on the principle of strain superposition, the principle of stress consistency, the principle of stress sharing and the principle of strain coincidence, the concept of influence height of rock bridge is introduced. The deformation equivalence of jointed rock mass is deduced. (2) Random effect of deformation of jointed rock mass. In this paper, by means of Monte Carlo method, a representative structural plane network sample is generated. Based on the composite element method, a numerical test method of three-dimensional flexibility tensor is established, and the complex jointed rock mass of SW hydropower station is used as the research object. The random characteristics of the deformation parameters of jointed rock mass are studied by statistical analysis of each component of the three-dimensional soft-degree tensor of rock mass. The results show that the three-dimensional equivalent flexibility tensor of each group of structural plane network samples is different from the distribution of the structural plane, but each component is subject to certain statistical rules. Based on the weak weathered jointed rock mass on the left bank of SW hydropower station, the three-dimensional flexibility tensor is closest to the lognormal distribution. (3) Based on the structural plane parameter inversion of rock mass on-site deformation test and the prediction of the equivalent flexibility tensor of rock mass. Based on the results of site deformation test of rock mass, combined with the structural surface geological survey and rock indoor test, the deformation parameters of the structural plane, which are mainly controlled by the structural surface network, are inverted by the numerical test method of the structural plane network discrete simulation. The equivalent flexibility tensor of the position of the test point is obtained and the equivalent flexibility tensor of the area rock mass is predicted. The reliability of the inversion results is proved by using the flexibility tensor obtained by inversion to test the rigid pressure bearing plate. (4) Numerical analysis model of multi-scale structural surface of dam foundation rock mass. Combined with the advantages of equivalent simulation and discrete simulation, the model can take into account the structural plane of fault and so on, and also consider the random structure surface of grade 鈪，
本文编号：2274269
[Abstract]:The structural surface controls the deformation and stability of rock foundation, rock slope and surrounding rock of underground cavity, and is the source of the complexity of mechanical properties of rock mass. The deformation characteristics of jointed rock mass show remarkable non-uniformity, anisotropy, size effect and random effect because of the dense and uneven distribution of the structure surface and the randomness of the spatial distribution between the structural planes. In depth study of the deformation characteristics of jointed rock mass, it has important theoretical and engineering significance for making full use of rock mass and targeted reinforcing rock mass. At present, the means of obtaining the deformation parameters of jointed rock mass mainly include engineering experience method, field test method, analytical method and numerical test method. The deformation characteristics of jointed rock mass have been studied by scholars both at home and abroad. However, the following shortages still exist: (a) the analytical method can well explain the deformation characteristics of the regular and penetrating joints, but lack reasonable simulation of the non-penetrating joint deformation mechanism; (b) the discrete existence of the three-dimensional structural plane network model is more difficult, so that the results of discrete simulation based on the three-dimensional structural plane network are less, and the randomness analysis of the three-dimensional equivalent parameter is more lacked; and (c) the numerical test method is high-efficiency, However, the comparison and verification of the results of field deformation test of rock mass are lacking, and (d) the influence of the anisotropy of jointed rock mass on hydraulic structure, especially on the working state of high arch dam-dam foundation system is seldom reported. In view of these main problems, the paper adopts the method of theoretical analysis, indoor and outdoor test, numerical simulation and engineering experience, and studies the following aspects: (1) anisotropy of joint rock mass deformation. On the basis of the principle of strain superposition, the equivalent elastic structure is derived for regular penetration of jointed rock mass, and the spatial characteristics of several special penetrating jointed rock mass deformation are analyzed. The results show that the deformation characteristics of the layered jointed rock mass are symmetric in the direction of the normal direction of the joint, the deformation characteristics of the columnar joint rock mass are symmetric about the plane in space, and the rock mass properties of the three groups of orthogonal joints are spatially symmetrical about the plane. Through the fine simulation of non-penetrating jointed rock mass, it is verified that the rock bridge has the function of nail tip and shear, and based on the principle of strain superposition, the principle of stress consistency, the principle of stress sharing and the principle of strain coincidence, the concept of influence height of rock bridge is introduced. The deformation equivalence of jointed rock mass is deduced. (2) Random effect of deformation of jointed rock mass. In this paper, by means of Monte Carlo method, a representative structural plane network sample is generated. Based on the composite element method, a numerical test method of three-dimensional flexibility tensor is established, and the complex jointed rock mass of SW hydropower station is used as the research object. The random characteristics of the deformation parameters of jointed rock mass are studied by statistical analysis of each component of the three-dimensional soft-degree tensor of rock mass. The results show that the three-dimensional equivalent flexibility tensor of each group of structural plane network samples is different from the distribution of the structural plane, but each component is subject to certain statistical rules. Based on the weak weathered jointed rock mass on the left bank of SW hydropower station, the three-dimensional flexibility tensor is closest to the lognormal distribution. (3) Based on the structural plane parameter inversion of rock mass on-site deformation test and the prediction of the equivalent flexibility tensor of rock mass. Based on the results of site deformation test of rock mass, combined with the structural surface geological survey and rock indoor test, the deformation parameters of the structural plane, which are mainly controlled by the structural surface network, are inverted by the numerical test method of the structural plane network discrete simulation. The equivalent flexibility tensor of the position of the test point is obtained and the equivalent flexibility tensor of the area rock mass is predicted. The reliability of the inversion results is proved by using the flexibility tensor obtained by inversion to test the rigid pressure bearing plate. (4) Numerical analysis model of multi-scale structural surface of dam foundation rock mass. Combined with the advantages of equivalent simulation and discrete simulation, the model can take into account the structural plane of fault and so on, and also consider the random structure surface of grade 鈪，
本文编号：2274269
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