细颗粒含量及含水率对粉砂土抗剪强度影响研究

Study on Influence of Fine Particle Content and Water Content on Shear Strength of Silty Soil

依托某路基试验土样,通过不同细颗粒含量和含水率下的直剪试验,对粉砂土的黏聚力和内摩擦角进行分析。结果表明:当含水率处于最优含水率左侧的过渡区时,随细颗粒含量增大,土体的黏聚力减小,当含水率大于最优含水率时,随着细颗粒含量增大,黏聚力增大;随着含水率增大,黏聚力呈现出先增大后减少的规律,当细颗粒含量为15%时该效应最为明显;随着细颗粒含量增大,内摩擦角呈下凹趋势,先减少后增大,临界值范围15%~20%;随含水率增大,内摩擦角整体呈下降趋势。

Based on the subgrade test soil sample,the cohesion and internal friction angle of the silty soil are analyzed through direct shear tests at different fine particle content and water content.The results show that when the water content is in the transition zone to the left of the optimum water content,the cohesion decreases with the increase of the fine particle content.When the water content is greater than the optimum water content,the cohesion of soil increases with the increase of fine particle content.With the increase of the water content,the cohesion shows the law of increasing first and then decreasing,and the effect is most obvious when the fine particle content is 15%.With the increase of fine particle content,the internal friction angle of silty-fine sand shows a downward trend,decreasing first and then increasing,and the range of critical value is 15%~20%;with the increase of water content,the internal friction angle of soil also shows a decreasing trend as a whole.