郭松峰, 祁生文, 李星星, 邹宇, 张世殊. 2016: 含结构面岩体试样单轴强度与变形特征. 工程地质学报, 24(5): 891-898. DOI: 10.13544/j.cnki.jeg.2016.05.019
    引用本文: 郭松峰, 祁生文, 李星星, 邹宇, 张世殊. 2016: 含结构面岩体试样单轴强度与变形特征. 工程地质学报, 24(5): 891-898. DOI: 10.13544/j.cnki.jeg.2016.05.019
    GUO Songfeng, QI Shengwen, LI Xingxing, ZOU Yu, ZHANG Shishu. 2016: STRENGTH AND DEFORMATION CHARACTERISTICS OF ROCK SAMPLE WITH DISCONTINUITIES UNDER NUMERICAL UNIAXIAL COMPRESSION SIMULATION TESTS. JOURNAL OF ENGINEERING GEOLOGY, 24(5): 891-898. DOI: 10.13544/j.cnki.jeg.2016.05.019
    Citation: GUO Songfeng, QI Shengwen, LI Xingxing, ZOU Yu, ZHANG Shishu. 2016: STRENGTH AND DEFORMATION CHARACTERISTICS OF ROCK SAMPLE WITH DISCONTINUITIES UNDER NUMERICAL UNIAXIAL COMPRESSION SIMULATION TESTS. JOURNAL OF ENGINEERING GEOLOGY, 24(5): 891-898. DOI: 10.13544/j.cnki.jeg.2016.05.019

    含结构面岩体试样单轴强度与变形特征

    STRENGTH AND DEFORMATION CHARACTERISTICS OF ROCK SAMPLE WITH DISCONTINUITIES UNDER NUMERICAL UNIAXIAL COMPRESSION SIMULATION TESTS

    • 摘要: 结构面是岩体区别于岩石材料的一大特征,其产状、迹长、密度等参数对岩体的力学性质有着重要影响。本文利用FLAC3D对含结构面岩体试样的单轴压缩特性进行了较为系统的数值模拟研究。文中建立了含不同组贯通性结构面的岩体试样模型和含不同倾角及迹长的非贯通结构面岩体试样模型,对每个试样进行单轴压缩试验的数值模拟,结构体和结构面均采用Mohr-Coulomb剪切和拉伸破坏准则。模拟中用编制的伺服控制程序通过调节加载速度,控制试样内最大不平衡力,研究含结构面试样单轴压缩情况下的变形、强度及破坏方式等特征。模拟结果显示,含1-3组贯通性结构面试样呈现各向异性特征,而含4组贯通性结构面试件呈现各向同性特征。随着贯通性结构面数量的增多,同尺寸试件的变形强度参数劣化。含单组非贯通性结构面试件,其单轴压缩模拟试验的应力-应变曲线峰值后出现应力降。基于Mohr-Coulomb抗剪强度准则和损伤理论所得的解析解与数值模拟结果所得的非贯通性结构面试件的单轴压缩强度不符,说明用抗剪强度准则与损伤理论刻画非贯通结构面试样的强度并不合理。随着非贯通性结构面贯通率的增大,试件的变形、强度参数劣化。含单组结构面试件的破坏方式可分为结构面控制破坏,结构面部分控制破坏和结构面不控制破坏3种类型,而随着结构面组数的增多,结构面控制试样破坏的概率增加。

       

      Abstract: The discontinuities are the key factors that differentiate the rock mass and intact rock. The mechanical behaviours of rock mass are strongly affected by length, occurrence and consistency of the discontinuities. Characteristics-deformation, strength, failure modes of rock samples with various discontinuities under uniaxial compression have been studied based on the numerical modelling FLAC3D.Rock samples with different groups of penetrated discontinuities and different unpenetrated discontinuities have been set up. On the basis of these models, a number of numerical uniaxial compression tests have been carried out, in which the shear and tensile strength criterion(Mohr-Coulomb criterion) has been used. During the uniaxial compression simulation tests, a servo-control program is used to restrict the maximum unbalanced force through adjusting the applied velocity. The results of simulation tests are shown as follow: rock samples with fewer than 4 groups of penetrated discontinuities are anisotropic while those with 4 groups of penetrated discontinuities are nearly isotropic. The deformation and strength parameters get lower as the number of penetrated discontinuities get higher in rock sample with same size. Stress drop is observed after peak stress in the stress-strain curve of rock sample with unpenetrated continuity. Uniaxial compressive strength derived from simulation is different from that calculated by analytic method based on shear strength and damage theory, which indicates that shear strength criterion may be not suitable for rock mass with unpenetrated discontinuities. The deformation and strength parameters get lower as the continuity trace length bigger. The failure modes of rock samples with discontinuities can be divided into three types: discontinuity-controlled, discontinuity-half controlled and discontinuity-uncontrolled. As the number of groups increases the failure are more likely to be discontinuity-controlled.

       

    /

    返回文章
    返回