# Triaxial Experimental Study of Zinc Contaminated Red Clay under Different Temperature Conditions
###### Abstract  
Temperature is one of the important factors affecting the mechanical properties of geotechnical soils, and its role in engineering construction in China cannot be underestimated. In order to study the effects of temperature and zinc contamination concentration on the mechanical properties of Guilin local red clay, a temperature-controlled triaxial shear test was conducted on Guilin red clay under three variables of temperature, zinc contamination concentration and surrounding pressure. The test findings revealed that there are significant differences in the effects of temperature, zinc contamination concentration and surrounding pressure on the mechanical properties of Guilin red clay. The stress-strain curves of the red clay at various temperatures, contamination concentrations and envelope pressures are of the strain-hardening type, and the deformation modulus showed a tendency to increase rapidly with increasing strain, then decrease rapidly, and finally, decrease slowly. With the increase of temperature, the cohesion of Zn-contaminated red clay increases, while the angle of internal friction increases and then decreases, both of which increase the shear strength of red clay. As the concentration of Zn contamination grows, the shear strength of the red clay increases, while the internal friction angle increases and then decreases, and the shear strength of the soil increases and then decreases. The shear strength of the Zn-contaminated red clay improved as the surrounding pressure increased. temperature; stress-strain curves; modulus of deformation; shear strength; shear strength index 10.3090/app122110742. 12 10742. 12 120742. 12 12 10742. 12 12 12 10742. 1  
The improper discharge of heavy metals from mines such as these, resulting in their infiltrating and migrating into the geotechnical body, causes soil contamination that poses many difficulties for engineering construction. Since the beginning of the new century, governments and enterprises have paid increasing attention to environmental protection issues; consequently, countries have increased their investment in research and treatment of contaminated soil and water bodies to cope with the deteriorating environmental problems. In recent decades, domestic and international scholars have conducted a great deal of research and treatment on soils and contaminated soils under a variety of conditions. Some scholars have studied the variation pattern of shear strength and index of red clay under conventional physical independent variables [18], including dry density, water content, fracture degree, and other variables. Some scholars have studied the evolution pattern of mechanical strength of red clay under different engineering conditions [19; 20; 21], and explored the microstructural changes that accompany the mechanical evolution process under different engineering conditions [20]. In terms of soil improvement, researchers have improved the engineering properties of the original soil by incorporating various amendments into the soil [1; 3; 10; 22; 23; 24], such as increasing the strength of the soil, altering the distribution of soil pores and volume, etc. In their investigation of contaminated soils, researchers have also achieved some research results. Currently, some researchers are concentrating on the properties of non-heavy metal contaminated soils [25; 26], including shear strength and microstructure. As for the research on soils contaminated with heavy metals, the main focus is on the study and management of the properties of contaminated soils. [PERSON]. [PERSON] et al. investigated the effects and mechanisms of zinc and chromium ions on the shear strength and structure of red clay [2; 27; 28]; [PERSON] et al. [29] revealed the intrinsic link between shear strength and resistivity of copper ion-contaminated red clay through experimental studies; [PERSON]. [PERSON] et al. [30] investigated the variation law of unconfined compressive strength of lead-contaminated soil after freeze-thawing. [PERSON] et al.