含填充裂隙硬岩单轴压缩破裂过程研究

发布时间：2018-02-17 02:38

本文关键词： 含填充裂隙单轴压缩裂隙扩展数字图像相关法起裂应力　出处：《湖北工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：由于地壳在不断运动和发展,岩体大多时候呈现出明显的不连续性,存在大量的节理、裂隙等结构面。结构面的特征在很大程度上决定了岩体在受力作用下的变形机制和破坏方式。为了研究含填充裂隙岩石的破坏过程和破裂机理,论文主要进行了如下工作:(1)对含有不同裂隙倾角、不同填充物的大理岩进行单轴压缩破坏过程试验,分析不同倾角、不同填充物条件下裂隙硬岩破裂过程的变形场演化特征、应力-应变曲线、强度特征、预制裂隙起裂点、起裂角和扩展形态等变化趋势,研究裂纹倾角和填充物对岩体破坏过程和破坏模式的影响,并在此基础上修正了含填充裂隙硬岩的本构模型。(2)采用弹塑性细胞自动机模拟系统EPCA2D,对不同裂纹倾角、不同填充和不同裂纹宽度等条件下,裂隙硬岩的单轴压缩试验进行数值模拟计算,对比试验结果,分析不同条件对裂隙硬岩破裂过程、强度、裂纹扩展模式等的影响机制。结果表明:(1)对于含有填充物的裂隙硬岩,随着裂隙倾角的增大,起裂点距离裂隙尖端越来越近,起裂角越来越小,硬岩的整体强度会有先减小后增大的趋势;(2)当裂隙中含有填充物时,硬岩的强度较无填充硬岩有明显的提高,且提高幅度会随着填充物弹性模量的增大而增大;(3)当裂隙中没有填充物时,硬岩强度会随着裂隙宽度的增大而减小,但当裂隙中含有不同填充时,硬岩强度会因裂隙宽度的变化而呈现不同的变化规律。(4)无论裂隙填充与否,裂隙硬岩在单轴压缩条件下的破坏大都是张拉和剪切共同作用的结果,但破坏形态会有所不同。当裂隙中含有填充时,剪切破坏更为明显;而当裂隙中没有填充时,张拉破坏更为显著。通过上述工作,讨论了不同裂隙特征、不同充填材料对硬岩破坏过程的影响,总结了不同条件下裂纹的扩展模式,对实际工程有一定的指导意义。
[Abstract]:Because of the continuous movement and development of the earth's crust, the rock mass presents obvious discontinuity in most of the time, and there are a large number of joints. In order to study the failure process and fracture mechanism of rock filled with fissures, the deformation mechanism and failure mode of rock mass under stress are determined to a great extent by the characteristics of structural planes such as fissures. The main work of this paper is as follows: (1) the uniaxial compression failure tests of marble with different fracture inclination and different fillers are carried out, and the evolution characteristics of fracture field of fractured hard rock under different dip angles and different filling conditions are analyzed. The stress-strain curves, strength characteristics, prefabricated crack initiation points, crack initiation angles and propagation patterns are studied. The effects of crack inclination and fillers on the failure process and failure mode of rock mass are studied. On the basis of this, the constitutive model of hard rock filled with fissures is modified. (2) Elastoplastic cellular automata simulation system EPCA2D is used for different crack inclination, different filling and different crack width, etc. The uniaxial compression test of fractured hard rock is numerically simulated and compared with the experimental results. The influence mechanism of different conditions on fracture process, strength and crack propagation mode of fractured hard rock is analyzed. The results show that: 1) for fractured hard rock containing filler, With the increase of crack inclination, the initiation point is closer to the crack tip, and the initial crack angle is smaller and smaller. The overall strength of hard rock will decrease first and then increase. The strength of hard rock is obviously higher than that of unfilled hard rock, and the increase range will increase with the increase of elastic modulus of filler. (3) when there is no filler in the crack, the strength of hard rock will decrease with the increase of crack width. But when the fracture contains different filling, the strength of hard rock will show different change law because of the change of crack width. (4) regardless of whether the crack is filled or not, the failure of fractured hard rock under uniaxial compression is mostly the result of the combined action of tension and shear. But the failure pattern will be different. When the fracture contains filling, the shear failure is more obvious, but when the fracture is not filled, the tensile failure is more obvious. Through the above work, the different fracture characteristics are discussed. The influence of different filling materials on the failure process of hard rock is summarized, and the crack propagation mode under different conditions is summarized, which has certain guiding significance for practical engineering.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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