Effect of unevenly distributed fine-grained soil in space on moisture migration

被引:0
|
作者
Yu Q. [1 ]
Tai B. [2 ]
Niu J. [1 ]
Wang G. [1 ]
Liu Z. [1 ]
Feng Y. [1 ]
Ma Z. [3 ,4 ]
机构
[1] Ningbo East China Nuclear Industry Engineering Investigation Institute, Ningbo
[2] State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou
[3] School of Civil and Traffic Engineering, Qinghai Nationalities University, Xining
[4] College of Traffic & Transportation, Chongqing Jiaotong University, Chongqing
关键词
Fine-grained soil; Freeze-thaw cycle; Moisture migration; Permafrost embankment; Uneven distribution;
D O I
10.11817/j.issn.1672-7207.2020.12.024
中图分类号
学科分类号
摘要
To study the water migration caused by unevenly spatial distribution of fine-grained soil in the roadbed filling of coarse-grained soil of expressway in permafrost area, the water migration of unevenly specimens under the condition of normal temperature and freeze-thaw cycle was measured. The effect of spatial non-uniform distribution of fine-grained soil, spatial distribution difference of particle size and temperature conditions on moisture migration degree was contrastively analyzed. The effects of initial state parameters on the spatial distribution of fine-grained soil and the spatial distribution difference of particle size were studied. The threshold condition of moisture migration was predicted by modeling. The results show that under the condition of freeze-thaw cycle and normal temperature, the more uneven the distribution of fine-grained soil is, the greater the difference of water content between upper and lower layers of samples is, which means that the water migration from the lower layer to the upper layer is more obvious. The degree of water migration increases with the increase of non-uniformly spatial distribution degree of fine-grained soil and particle size under two temperature conditions. When the spatial non-uniform distribution of particle size caused by the difference of particle group average diameter is greater than 78.33%, the degree of water migration increases rapidly. The increase of spatial non-uniform distribution and difference of particle size distribution of fine-grained soil are mainly caused by the increase of fine-grained mass fraction and the decrease of average particle size of the largest particle group, and the effect of initial void ratio ranked the third. When the temperature is constant, there is a quadratic function relationship between the parameters of water migration degree and the spatial non-uniform distribution of fine-grained soil. The main stage of water migration occurs in the first day at normal temperature or in the melting stage of the first freeze-thaw cycle. The moisture migration degree of specimens with the characteristics of non-uniform distribution during freeze-thaw cycles is significantly higher than that at normal temperature. The maximum content of moisture migrating from the lower layer to the upper layer of unevenly specimen under the condition of freeze-thaw cycle is 38%. © 2020, Central South University Press. All right reserved.
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页码:3503 / 3514
页数:11
相关论文
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