Sensitivity Analysis of Loess Triaxial Mesoscopic Parameters Based on PFC3D

Abstract Based on PFC3D software and theory, combined with the indoor triaxial test results to calibrate the basic micro parameters of numerical simulation, through a large number of literature reading, respectively, the friction coefficient, porosity, particle size distribution are determined as the sensitivity factors affecting the triaxial numerical simulation of loess. The conventional triaxial numerical simulation of loess numerical samples under 200kPa confining pressure was conducted. The sensitivity analysis of meso-parameters is carried out by changing the degree of influence of meso-parameters such as the minimum particle radius on the macro-mechanical behavior of loess numerical samples, and the relationship between micro parameters of soil and macro mechanics is established. The results show that the order of the influence of particle mesoscopic parameters on peak strength is as follow: porosity> friction coefficient between particles>particle size distribution; the order of influence on residual strength is as follow: porosity>friction coefficient between particles>particle stiffness ratio>particle size distribution; the order of influence on the initial linear elastic modulus of the loess material is as follow: porosity>friction coefficient between particles>particle size distribution; the order of effect on softening characteristics is as follow: porosity>friction coefficient between particles>particle size distribution.