中文摘要：

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。

英文摘要：

Based on the particle flow theory,the model of backfill sample was created by PFC software and the numerical simulation experiment of uniaxial compression was carried out. The control variable method was used to conduct the sensitivity analysis of several mesoscopic parameters,such as parallel bond strength,particle stiffness ratio,grain composition,friction coefficient,etc. to find out the influences of mesoscopic parameters on macroscopic properties. The results show that： Parallel bond strength mainly influences the strength of the backfill,less effect on the elastic modulus; The increase of particle stiffness ratio may increase the effect of rigid contact of particles and reduce the role of parallel bond,which is mainly shown as tension failure; The friction coefficient mainly affects the strength of the backfill. The larger friction coefficient may induce the stronger bite force between particles and heavier residual strength of sample after the destruction; Parallel bond strength has the largest influence on the strength of the backfill. The results have a great guiding significance in matching the compressive strength,elastic modulus and other macro parameters to micromechanics parameters of the backfill,which can lay the foundation for the debugging and modeling of the mesoscopic parameters.