Sensitivity analysis of macro-micro parameters of soil-structure interface

In order to study the effect of various micro parameters of the soil-structure contact interface on the macro response, starting from the meso structure of the soil, a two-dimensional discrete element method is used to conduct a biaxial shear numerical test. The sensitivity analysis is carried out for the friction factor, particle shape, void ratio of the particles, normal stress, stiffness ratio and other parameters. The influence of various micro parameters on the macro response is found. It also establishes a cross-scale correlation of the micro-macro parameters of the granular material at the contact interface, and reveals the meso-mechanical behavior of the granular material at the contact interface mechanism. The results show that friction factor, porosity ratio, particle shape and normal stress have a greater influence on the peak strength of the contact interface, stiffness ratio has a smaller influence on the peak strength of the contact interface; friction factor, normal stress and stiffness ratio have an influence on the elastic modulus. The effect is significant, in which the friction factor is approximately proportional to the internal friction angle, and it has a greater impact on the shear strength and shear dilatancy of the soil. The combined arc particles are closer to the true sand shape than the round particles, and the simulation effect is better. The critical strength and critical porosity ratio are not affected by the initial porosity ratio and the shear strength of the combined arc particles is affected by the normal stress. The greater the normal stress, the greater the shear strength of the particles. The research results provide a theoretical reference for material optimization and modification of the contact interface.