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

Suran Wang^1,2，Yu Huang^1,2*

1 Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China

2 Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education, Tongji University, Shanghai 200092, China

摘要

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.

主要内容

这项研究论文调查了高温下石英砂剪切特性的演化，这对于理解长距离滑坡行为很重要。作者对一系列峰值温度下的石英砂样品进行了热处理实验，然后进行动态环形剪切试验来分析剪切行为、强度、残余剪切应力、密度、颗粒尺寸变化和矿物成分变化。关键发现是：暴露在高温下的石英砂更易破碎，其密度发生变化，颗粒尺寸对残余剪切应力和剪切应力波动有很大影响，而存在铜-金-铁等金属元素会对砂的剪切性能产生不利影响。

主要观点

暴露在高温下的石英砂更容易破碎，其密度也会发生变化
颗粒尺寸对残余剪切应力和剪切应力波动幅度有很大影响
经过热处理后在样品中发现的铜-金-铁等金属元素可能会对砂子的剪切性能产生不利影响

引用格式

[1] Wang SR, Huang Y*. Experimental study on the shear characteristics of quartz sand exposed to high temperatures[J]. Acta Geotechnica, 2022, 17: 5031-5041. https://doi.org/10.1007/s11440-022-01603-8