Experimental study on the shear characteristics of quartz sand exposed to high temperatures

We have investigated the evolution of the shear characteristics of quartz sand subjected to high temperatures present in long-runout landslides. Quartz sand samples were subjected to quantitative heat treatment at a range of peak temperatures. Based on the principle of the irreversibility of mechanical characteristics of soil materials after heating, dynamic ring-shear experiments were subsequently performed and the sample density and X-ray powder diffraction patterns were analyzed. The shear behavior, shear strength, residual shear stress, density of samples, particle size variation, and mineral composition variation were analyzed and the main conclusions are as follows: (1) quartz sand that has been exposed to high temperatures is more easily broken and its density changes; (2) particle size has a substantial influence on the residual shear stress and the amplitude of shear stress fluctuation; (3) copper-gold-iron was found in the samples after heat treatment. We interpret this to mean that a small quantity of metallic elements in the quartz can have adverse effects on the shear properties of the sand with exposure to high temperature.

Automated summary

This study investigated the evolution of shear characteristics of quartz sand subjected to high temperatures in long-runout landslides. The results revealed that high temperature exposure caused the quartz sand to easily break and undergo density changes. Additionally, particle size had a significant impact on the residual shear stress and shear stress fluctuation amplitude, while the presence of copper-gold-iron in the samples after heat treatment had adverse effects on the shear properties of the sand.