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金属矿山 ›› 2021, Vol. 50 ›› Issue (09): 27-36.

• 采矿工程 • 上一篇    下一篇

基于颗粒流GBM模型的花岗岩声发射相对平静期特征研究

赵  奎1,2  刘永光1,2  曾  鹏1,2  伍文凯1,2  王金鉴1,2   

  1. 1. 江西理工大学资源与环境工程学院,江西 赣州 341000;2. 江西理工大学江西省矿业工程重点实验室,江西 赣州 341000
  • 出版日期:2021-09-15 发布日期:2021-10-07
  • 基金资助:
    “十三五”国家重点研发计划项目(编号:2017YFC0804601);国家自然科学基金项目(编号:51664018);江西省博士后科研择优资助项目(编号:2020KY39);江西理工大学博士启动基金项目(编号:jxxjbs17063)

Study on the Acoustic Emission Characteristics of Granite in Relative Calm Period Based on GBM Model of Particle Flow Code

ZHAO Kui1,2    LIU Yongguang1,2    ZENG Peng1,2    WU Wenkai1,2    WANG Jinjian1,2   

  1. 1. School of Resources and Environmental Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;2. Jiangxi Provincial Key Laboratory of Mining Engineering,Jiangxi University of Science and Technology,Ganzhou 341000 ,China
  • Online:2021-09-15 Published:2021-10-07

摘要: 为了研究不同晶体粒径大小对花岗岩声发射相对平静期的影响,基于颗粒流软件PFC2D构建花岗岩等效晶体模型GBM(Grain-based model, GBM)数值计算模型,通过室内试验结果对细观参数进行标定,模拟花岗岩试件单轴压缩声发射试验。分析了不同晶体粒径大小对试件应力—应变、峰值强度的影响规律,着重分析了试件破坏过程中裂纹、声发射时空演化特征及相对平静期的产生机理。同时,研究了试件声发射相对平静期前后能量变化特征及其与晶体粒径大小的关系。研究结果表明:①随着晶体粒径增大,试件的单轴抗压强度增大。试件破坏形式主要呈“X”型剪切和“V”型柱状劈裂。同时不同晶体粒径大小试件的微裂纹均以张拉破坏为主,且首先产生沿晶微裂纹,在声发射相对平静期起始点开始产生穿晶微裂纹。②试件在单轴压缩过程中,声发射在应力峰值前均出现不同程度的相对平静期,且在相对平静期前声发射产生的位置为沿晶体边界;在相对平静期起始点之后,将同时产生位于晶体内部和晶体边界的声发射。③声发射相对平静期内滑移能和阻尼能的变化量随着晶体粒径的增大逐渐减小。其中,由于在声发射相对平静期内声发射明显减少,岩石内部活动处于相对平静状态,因此释放的动能减少。

关键词: 声发射, 等效晶体, 颗粒流, 相对平静期, 花岗岩

Abstract: In order to study the influence of different crystal particle sizes on the acoustic emission calm period of rocks,a granite equivalent crystal model GBM (Grain-based model,GBM) numerical calculation model was constructed based on the particle flow code PFC2D. The microscopic parameters were calibrated through laboratory test results, which simulates the uniaxial compression acoustic emission test of granite specimens. The influence law of different crystal particle sizes on stress-strain and peak strength of specimens was analyzed. And the spatial and temporal evolution characteristics of cracks, acoustic emission events and the generation of relative quiet period during the failure process of specimens were emphatically analyzed. At the same time, the energy variation characteristics of before and after acoustic emission quiet period of specimens and the relationship between the energy variation and the crystal particle size were studied. The results show that: ①With the increase of crystal size, the uniaxial compressive strength of specimens increases. The failure forms of the specimens were mainly X-shear and V-columnar splitting. At the same time, the specimens with different crystal particle sizes were mainly damaged by tension, and the intergranular microcracks first occurred, and the transgranular microcracks began to occur at the starting point of acoustic emission quiet period.② In the uniaxial compression process of specimens, acoustic emission appears relative calm periods of varying degrees before the stress peak. In addition, the location of acoustic emission generation before the quiet period is along the crystal boundary, and after the beginning point of the quiet period, acoustic emission located in the crystal interior and the crystal boundary will be generated simultaneously.③ The variation of slip energy and damping energy decreases with the increase of crystal particle size in the acoustic emission quiet period.Among them,due to the significant decrease of acoustic emission during the quiet period of acoustic emission,the activity inside the rock is in a relatively calm state,so the released kinetic energy is reduced.

Key words: acoustic emission, equivalent crystal, PFC, relative calm period, granite