【摘要】 近年来频发的地质灾害使得深入研究大坝堆石体受力变形机制显得愈发迫切和重要。针对堆石颗粒具有形状极其不规则、咬合作用突出的特点,编写了一个简单易用的程序来随机生成形状不规则的数值颗粒。以正四面体为核,按照晶胞繁衍的方式,生成堆石的仿真颗粒集合体。模拟排水剪切条件下的大三轴试验,通过分析数值试验过程中细观参量的变化规律,探讨三轴剪切条件下堆石体变形的细观机制。分析表明,按照晶胞繁衍法生成的数值颗粒与圆颗粒相比能更好地模拟堆石,由颗粒簇形成的咬合力能形成更真实的力-变形关系;数值试验得到的应力-应变曲线和体变曲线与室内三轴试验结果基本一致;颗粒的破碎速率是联系堆石体宏、细观力学性质的重要纽带,通过分析堆石体颗粒破碎4个阶段细观参量的变化规律,深化了对堆石体变形机制的认识。更多还原

【Abstract】 In recent years the frequent geological disasters make deep research on deformation mechanism for rockfill increasingly urgent and important.Rockfill has the characteristics of irregular shape and prominent interlock behavior;and a simple program is used to generate arbitrary shape of particle clusters.Taking tetrahedron as core,arbitrary shape of particle clusters are generated by crystal cell reproduction method.The particle clusters are used as basic unit to generate aggregation of particles so as to simulate the large scale triaxial drained shear test for rockfill and study the mesoscopic mechanism of rockfill deformation by analyzing the change law of mesoscopic parameters in experiment.The analysis shows that the stress-strain curves and volumetric deformations from numerical simulation are in agreement well with the test results;and the arbitrary shaped clusters are much better than circle particles in simulating the rockfill.The breakage rate is the bridge linking the properties of macroscopic parameters and mesoscopic parameters.With the analysis of the change law of mesoparameters among four stages of particle breakage,the mechanism of rockfill deformation is given.更多还原