# Numerical Study on the Mechanical Behavior of Sand-Rubber Mixtures under True Triaxial Tests  
[PERSON]  
School of Civil Engineering, Architecture and Environment, Hubei University of Technology,  
Wuhan 430086, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (H.D. );  
[EMAIL_ADDRESS] (L.Y. ); [EMAIL_ADDRESS] (Z.C. );  
Correspondence:. [EMAIL_ADDRESS]  
Xiang Gao  
School of Civil Engineering, Architecture and Environment, Hubei University of Technology,  
Wuhan 430086, China; [EMAIL_ADDRESS] (Y.C. ); [EMAIL_ADDRESS] (H.D. );  
[EMAIL_ADDRESS] (L.Y. ); [EMAIL_ADDRESS] (Z.C. );  
102110932@hbut. the internal friction angle decreases linearly. At the same time, through indoor unconfined compression experiments and scanning electron microscopy experiments, it was found that the loaded medium under low rubber content is mainly sand-sand contact, and under high rubber content, the load depends on the large deformation of rubber particles. [PERSON] et al. [12] studied the effect of particle types on the mechanical properties of RSMs through indoor triaxial experiments and dynamometer experiments, and found that the strength of the sand particles affects the yield rate during compression. Meanwhile, except for the highest RC, the critical-state stress ratio and stress-strain behavior of the RSM are controlled. [PERSON] et al. [10] analyzed the influence of RC on the dynamic strength characteristics and dynamic pore pressure development of a mixture through indoor dynamic triaxial experiments, and found that the higher the rubber content, the higher the liquefaction resistance of the RSM. [PERSON] et al. [13] found the same law in their study of the dynamic characteristics of sand samples mixed with rubber powder under saturated undrained conditions, and further showed that rubber powder with a larger particle size can greatly improve the resistance of the sample in terms of liquefaction ability. [PERSON] and [PERSON] et al. [14,15] studied the influence of RC on the dynamic shear modulus and damping ratio in a series of large-scale indoor cyclic simple shear experiments. [PERSON] et al. [16] studied the static and dynamic characteristics of sand-tire-scrap mixtures under high-strain conditions. [PERSON] et al. [17,18] established a numerical model of a binary RSM by means of the discrete element method and conducted a series of triaxial tests to study the effects of the rubber particle size and the rubber particle content on the mechanical state, the critical state and the unstable behavior of the RSM under static loading. At the same time, [PERSON] et al. [19] and [PERSON] et al. [20,21] conducted a micro-mechanical study of an RSM with a small strain state and obtained micro-scale information about all the experiments. [PERSON] et al. [22] analyzed the mechanical behavior of an RSM with large rubber particles. Based on the research on rubber-sand mixtures by domestic and foreign scholars, laboratory tests and numerical simulations are mainly used to study various mechanical properties of rubber-sand, and most of them are concentrated on the effects of sand type, rubber content, particle size and consolidation pressure on the macro-micro strength deformation characteristics and influence mechanism of RSMs. However, there are few studies considering the mechanical properties of RSMs under complex stress paths, and there are insufficient studies on the practical applications of materials in engineering. This paper uses the three-dimensional discrete element method to systematically analyze the effect of the intermediate principal stress ratio on the strength characteristics of RSMs with different RCs and discuss the corresponding mesoscopic mechanism. This study analyzes the influence of rubber content RC on the relationship between friction angle and \(b\) value, and compares it with several common strength criteria.