粒径大小对颗粒堆积体Burgers模型蠕变参数相似试验研究

Similar experimental study on the effect of particle size on the creep parameters of Burgers model of granular accumulation

  • 摘要: 为研究砂土颗粒材料堆积体在沉降过程中的变形行为,采用分级加载的方式进行三轴压缩蠕变试验,获得3组不同粒径(0.6~0.8 mm、1.0~1.5 mm、2.0~2.5 mm)的玻璃微珠蠕变变形-时间曲线,选取四元件Burgers模型对试验曲线进行拟合分析,得到玻璃微珠蠕变特性表征参数,并建立离散元数值模型对burgers模型参数进行验证。研究结果表明:玻璃微珠在三轴压缩条件下的蠕变特性可采用Burgers模型进行描述,蠕变Burgers模型的4个参数EkEmηkηm与粒径和轴压均呈现负相关关系。将试验拟合得到的宏观Burgers模型参数转换为颗粒流程序中的微观Burgers模型参数,模拟结果与试验结果具有较高的吻合性,对比结果说明颗粒流Burgers模型适用于岩石颗粒蠕变试验的研究。

     

    Abstract: In order to study the deformation behavior of sand granular material accumulation during settlement, this study carried out the triaxial compression creep test by step loading, and obtained three groups of creep deformation-time curves of glass beads with different particle sizes (0.6~0.8 mm, 1.0~1.5 mm, 2.0~2.5 mm).The four element Burgers model was selected to fit and analyze the test curve, from which the parameters of creep characterization of glass beads were obtained.The discrete element numerical model was established to verify the parameters of the Burgers model.Results show that the creep characteristics of glass beads under triaxial compression can be described by the Burgers model.The four parameters EkEmηkηmof the Burgers model have negative correlation with particle size and axial pressure.The macro Burgers model parameters obtained from the test are transformed into the micro Burgers model parameters in the particle flow program.The simulation results are in good agreement with the test results.The comparison results verify that the particle flow Burgers model is suitable for the experimental study of rock particle creep.

     

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