基于PFC3D的粉质黏土三轴压缩破坏过程分析

ANALYSIS OF TRIAXIAL COMPRESSION FAILURE PROCESS OF SILTY CLAY BASED ON PFC3D

为从细观角度探究粉质黏土在三轴试验加载过程中变形破坏演变过程,文中通过PFC(Particle Flow Code)3D软件模拟三轴剪切试验过程,从颗粒位移场、强接触组构变化、强接触力分布规律、配位数、黏结断裂等方面对粉质黏土变形破坏的细观演变过程进行分析研究。研究结果表明,试样剪切带随轴向应变增大而变窄,10%轴向应变时试样中部颗粒位移值最大;试验后期配位数相较于前期逐渐均匀化;黏结断裂随轴向应变的增大而呈线性增大,不完美黏结也随之增大,且试验初期没有发生黏结断裂;强接触力分布函数在试验中期显著增大而后期逐渐减小,且服从对数正态分布。研究成果以期为土体研究提供方法与参考。

This paper investigates silty clay's deformation and failure evolution during triaxial test loading from a mi⁃croscopic perspective.Particle flow code(PFC)3D software is used to simulate the triaxial shear test process,and the tiny evolution process of deformation and failure of silty clay is analyzed from the aspects of the particle displace⁃ment field,strong contact fabric change,strong contact force distribution,coordination number,bond fracture and so on.The results show that the shear band narrows with the increase of axial strain,and the displacement of particles in the middle of the sample is the largest when the axial strain is 10%.The coordination number in the late stage of the experiment gradually homogenized compared with that in the early stage.The bond fracture increases linearly with the increase of axial strain;the imperfect bond also grows with no bond fracture occurring in the initial stage of the test.The distribution function of the strong contact force increases significantly in the middle period of the exper⁃iment,and decreases gradually in the later period,following the lognormal distribution.The research results may pro⁃vide methods and references for macro and micro soil research.