颗粒级配和初始干密度是粗粒土强度特性的两个重要影响因素。为建立粗粒土级配、初始干密度指标与强度指标之间的定量规律。首先,基于多重分形级配方程,推导了单位体积内大于某粒径的颗粒个数与多重分形维数、干密度之间的定量表达式,并将其称之为“骨架颗粒数密度指标”;接着,开展了4种不同级配和密度组合的粗粒土三轴固结排水剪切试验,初步得出结论:连续级配粗粒土的破坏剪应力与骨架颗粒数密度指标之间呈线性递增规律;最后,对该结论进行了大量文献数据验证研究。该结论不仅可为粗粒料填筑优化方案的比选提供参考,对粗粒土强度缩尺效应的研究亦有一定启发作用。
Abstract
Particle gradation and initial dry density are two crucial factors that influence the strength characteristics of coarse-grained soils. In this paper we aim to quantify the relationship between gradation and initial dry density index of coarse-grained soil and its strength index. Based on the formula process of multiple fractal stages, we derived a quantitative expression, termed as the “skeleton particle density index”, which relates the relationship between the number of particles larger than a certain size per unit volume and the multiple fractal dimensions and dry density. Subsequently, we carried out four triaxial consolidation drainage shear tests on coarse-grained soils with various combinations of gradation and density. The destructive shear stress of continuously graded coarse-grained soil exhibited a linear increase with the skeleton particle density index of the skeleton particle density index. Finally, we conducted extensive literature data verification studies to validate our findings. The obtained results not only provide reference for comparing and selecting optimal schemes for coarse-grained material filling but also offer significant insights into the study of the scale effect on the strength of coarse-grained soils.
关键词
连续级配粗粒土 /
多重分形维数 /
骨架颗粒数密度指标 /
大型三轴剪切试验 /
破坏剪应力
Key words
continuous gradation of coarse-grained soil /
multiple fractal dimensions /
density index of skeleton particle number /
large triaxial shear test /
shear stress at failure
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基金
中央级公益性科研院所基本科研业务费专项(CKSF2021459/YT,CKSF2021484/YT)
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