基于颗粒流理论的充填体细观参数敏感性分析

发布时间：2018-07-13 14:00

【摘要】：基于颗粒流理论,借助PFC程序建立充填体试样模型,进行单轴压缩数值模拟试验,利用控制变量法分别对充填体试样平行黏结强度、颗粒刚度比、颗粒级配、摩擦系数等细观参数进行敏感性分析,研究以上细观参数对充填体力学特性的影响。研究结果表明:平行黏结强度主要影响充填体强度,对其弹性模量影响较小;颗粒刚度比变大会使颗粒间的刚性接触效应增加,从而削弱平行黏结作用,试验过程中会出现试样产生张拉破坏;摩擦系数对充填体试样强度影响较大,摩擦系数越大,颗粒之间的胶结力越大,试样在发生破坏后残余强度越大;平行黏结强度对充填体单轴抗压强度影响最大。研究成果对充填体抗压强度、弹性模量等宏观参数与细观力学参数的匹配具有指导意义,可为后期细观参数的调试和建模奠定基础。
[Abstract]:Based on particle flow theory, the model of backfill specimen was established by PFC program, and the uniaxial compression numerical simulation test was carried out, and the parallel bonding strength, particle stiffness ratio and particle gradation of the backfill specimen were calculated by the control variable method, respectively. The influence of the above meso-parameters on the mechanical properties of filling was studied by sensitivity analysis of meso-parameters such as friction coefficient. The results show that the parallel bonding strength mainly affects the strength of the filling body and has little effect on its elastic modulus, and the rigid contact effect between particles increases with the change of particle stiffness ratio, which weakens the parallel bonding effect. The tensile failure will occur in the test process, the friction coefficient will have a great effect on the strength of the backfill sample, the greater the friction coefficient, the greater the cementing force between the particles, and the greater the residual strength of the specimen after the failure. The effect of parallel bonding strength on the uniaxial compressive strength of the filling body is the greatest. The results can be used as a guide for the matching of macroscopic parameters such as compressive strength and modulus of elasticity with the meso-mechanical parameters, which can be used as a foundation for the adjustment and modeling of the meso-parameters in the later stage.
【作者单位】：武汉科技大学资源与环境工程学院;
【基金】：国家自然科学基金项目(编号:51604195) 大学生科技创新基金研究项目(编号:15ZRA184) 校青年科技骨干培育计划项目(编号:2016xz009)
【分类号】：TD853.34

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