人工合成透明砂与标准砂强度对比试验

Comparative Strength Tests on the Transparent Synthetic Sand and the Standard Quartz Sand

通过直剪试验,进行了人工合成透明砂与标准砂的一些性质对比,主要包括内摩擦角、粘聚力、应力~剪切位移曲线。对比发现,两者之间存在着一定差别,如合成透明砂的内摩擦角比标准砂大5.3°,粘聚力比标准砂大9.8 kPa。为配置出强度参数更接近标准砂的人工合成透明砂,通过对比不同单一粒径的透明砂和标准砂发现:两者内摩擦角都随着粒径的增大而增大;并且在粒径为0.1~0.25 mm时,透明砂的内摩擦角大于标准砂;在粒径为1.0~2.0 mm时,透明砂内摩擦角小于标准砂。然后依此规律为指导,改变合成透明砂的级配,测定不同级配下透明砂的特性,并与标准砂进行对比,找到了与标准砂内摩擦角相同的透明砂的级配。

This paper presents the comparative study between the synthetic transparent sand samples and the natural standard quartz sand samples throughout a series of direct shear tests.The characters mainly include the internal friction angle,the cohesion value and the stress-strain curve.Throughout the comparative study,it is concluded that there are some differences between the two sands,for instance,the internal friction angle of the synthetic transparent sand sample is larger than that of the standard quartz sand sample by 5.3°.The shear strength value is larger than the standard sand by 9.8kPa.To prepare a synthetic transparent sand sample that has similar direct shear parameters with that of natural standard quartz sand,studies on the test results from single grain size samples of both sand samples concluded that the internal friction angle increases with the increase of sample grain size;while the grain size of the sand sample is between 0.1 and 0.25 mm,the internal friction angle of the synthetic transparent sand is greater than that of standard quartz sand;However,when the sand sample has a grain size between 1.0 and 2.0 mm,the internal friction angle of synthetic transparent sand is smaller than that of the quartz sand.Based on the test results,the synthetic transparent sand with different gradation can have the same direct shear parameters with the natural standard quartz sand.