节理岩体力学特性的尺寸效应研究
发布时间：2018-11-16 15:31
【摘要】：尺寸效应是节理岩体力学性质的重要特征,表征单元体(Representative Elementary Volume)是尺寸效应研究的核心内容。本文围绕岩体力学性质的尺寸效应对节理岩体的变形参数与强度参数表征单元体REV及其分形特征进行了系统的研究,对合理选择节理岩体的力学介质模型与等效力学参数具有指导意义。主要内容有：综合采用数字摄影测量与数理统计技术,研究了不同分布形式的节理网络模拟方法,并编制了相应的计算程序。实践表明：该算法可以产生与研究区真实岩体结构在统计上完全等效的节理网络模型。采用RFPA2D数值分析软件重点研究了节理岩体变形和强度参数的尺寸效应与各向异性,并得到不同力学参数的REV大小。数值试验结果表明：研究区节理岩体的弹性模量B、剪切模量Gxy、单轴抗压强度即均随岩体试样尺寸的增大而变化,表现出明显的尺寸效应,当岩体试样尺寸增大到一定值后,这些参数均趋于稳定,并获得了研究区节理岩体的等效柔度矩阵[C]及宏观强度参数c、φ。综合采用岩体节理网络生成技术和数值分析方法,研究了岩体强度随节理分布分维的变化关系及其破坏模式。研究表明：分形维数越小,节理在岩体试样中分布越不均匀；节理岩体的单轴抗压强度随着分形维数的增大而增大；当节理岩体结构满足一定条件时,分形维数与岩体强度的关系也蕴含着尺寸效应的原理。
[Abstract]:Dimension effect is an important feature of mechanical properties of jointed rock mass, and the characterization of unit (Representative Elementary Volume) is the core of size effect research. Based on the size effect of mechanical properties of rock mass, the deformation and strength parameters of jointed rock mass are studied systematically in this paper. The REV and its fractal characteristics of the unit body are characterized by the parameters of deformation and strength of jointed rock mass. It is of guiding significance for the reasonable selection of mechanical medium model and equivalent mechanical parameters of jointed rock mass. The main contents are as follows: using digital photogrammetry and mathematical statistics technology, the paper studies the simulation method of joint network with different distribution forms, and compiles the corresponding calculation program. The practice shows that the proposed algorithm can produce a joint network model that is statistically equivalent to the real rock mass structure in the study area. The size effect and anisotropy of deformation and strength parameters of jointed rock mass are studied with RFPA2D numerical analysis software, and the REV values of different mechanical parameters are obtained. The numerical results show that the elastic modulus B and shear modulus Gxy, of jointed rock mass in the study area change with the increase of the specimen size, and show obvious size effect. When the specimen size increases to a certain value, the uniaxial compressive strength of the jointed rock mass changes with the size of the rock mass specimen. These parameters tend to be stable, and the equivalent flexibility matrix [C] and macroscopic strength parameters c, 蠁 of jointed rock mass in the study area are obtained. The variation of rock mass strength with the fractal dimension of joint distribution and its failure mode are studied by using the technique of rock mass joint network generation and numerical analysis. The results show that the smaller the fractal dimension, the more uneven the joint distribution in rock samples, and the greater the uniaxial compressive strength of jointed rock mass increases with the increase of fractal dimension. When the structure of jointed rock mass meets certain conditions, the relationship between fractal dimension and rock mass strength also implies the principle of size effect.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45
本文编号：2335892
[Abstract]:Dimension effect is an important feature of mechanical properties of jointed rock mass, and the characterization of unit (Representative Elementary Volume) is the core of size effect research. Based on the size effect of mechanical properties of rock mass, the deformation and strength parameters of jointed rock mass are studied systematically in this paper. The REV and its fractal characteristics of the unit body are characterized by the parameters of deformation and strength of jointed rock mass. It is of guiding significance for the reasonable selection of mechanical medium model and equivalent mechanical parameters of jointed rock mass. The main contents are as follows: using digital photogrammetry and mathematical statistics technology, the paper studies the simulation method of joint network with different distribution forms, and compiles the corresponding calculation program. The practice shows that the proposed algorithm can produce a joint network model that is statistically equivalent to the real rock mass structure in the study area. The size effect and anisotropy of deformation and strength parameters of jointed rock mass are studied with RFPA2D numerical analysis software, and the REV values of different mechanical parameters are obtained. The numerical results show that the elastic modulus B and shear modulus Gxy, of jointed rock mass in the study area change with the increase of the specimen size, and show obvious size effect. When the specimen size increases to a certain value, the uniaxial compressive strength of the jointed rock mass changes with the size of the rock mass specimen. These parameters tend to be stable, and the equivalent flexibility matrix [C] and macroscopic strength parameters c, 蠁 of jointed rock mass in the study area are obtained. The variation of rock mass strength with the fractal dimension of joint distribution and its failure mode are studied by using the technique of rock mass joint network generation and numerical analysis. The results show that the smaller the fractal dimension, the more uneven the joint distribution in rock samples, and the greater the uniaxial compressive strength of jointed rock mass increases with the increase of fractal dimension. When the structure of jointed rock mass meets certain conditions, the relationship between fractal dimension and rock mass strength also implies the principle of size effect.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45
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相关期刊论文 前3条
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3 李建林,王乐华;卸荷岩体的尺寸效应研究[J];岩石力学与工程学报;2003年12期
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