无黏性混合土临界细粒含量的多途径判别研究

发布时间：2018-08-18 14:10

【摘要】：临界细粒含量反映了无黏性混合土颗粒级配和结构性对力学性状的重要影响,其值的确定是一个相互验证的过程。假设无黏性混合土具有砂-粉二元结构,在此基础上通过理论分析颗粒骨架于孔隙比的影响,运用土体基本物理指标对临界细粒含量的范围进行了预测;最大孔隙比和最小孔隙比随着细粒含量的变化反映了颗粒的形状和相互间接触关系,由此得到的临界细粒含量也是区间值;分形理论中的分维数反映了土体颗粒结构的自相似性,通过分形维数变化情况的探讨进一步缩小了临界细粒含量的取值;稳态线反映出无黏性混合土的力学性质特征,取稳态线斜率变化处的细粒含量为临界细粒含量。后两种方法得到的临界细粒含量均在前两种方法获得的区间范围内。综合各种方法,得出由南京砂重塑得到的无黏性混合土的临界细粒含量为25%。
[Abstract]:The critical fine particle content reflects the important influence of particle gradation and structure on mechanical properties of non-clay mixed soil, and the determination of its value is a process of mutual verification. Based on the theory analysis of the influence of particle skeleton to porosity ratio, the range of critical fine grain content is predicted by using the basic physical index of soil. The change of the maximum porosity ratio and the minimum porosity ratio with the content of fine particles reflects the shape of particles and the contact relationship between them, and the critical fine particle content is also an interval value. The fractal dimension in fractal theory reflects the self-similarity of soil particle structure, and the change of fractal dimension further reduces the value of critical fine particle content, and the steady-state line reflects the mechanical properties of non-clay mixed soil. The content of fine grain at the change of steady line slope is taken as critical fine grain content. The critical fine particle content obtained by the latter two methods is within the range of the first two methods. By synthesizing various methods, the critical fine grain content of the clay-free mixed soil remolded from Nanjing sand is 25.
【作者单位】：常州工学院土木建筑工程学院;湖南科技大学土木工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金项目(41302226) 湖南省自然科学基金项目(10JJ1036) 江苏省自然科学基金项目(BK20131141)
【分类号】：TU441

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