Study on overburden pressure effect of expansive soil water characteristic curve

被引：0
|
作者：
Wang X. [1 ]
Xu C. [1 ]
Wang S. [1 ]
Li X. [1 ]
机构：
[1] College of Engineering and Technology, Southwest University, Chongqing
来源：
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | 2020年 / 39卷
基金：
中国国家自然科学基金;
关键词：
Bimodal soil-water characteristic curve; Consolidation yield stress; Expansive soil; Model; Overburden pressure effect; Soil mechanics;
D O I：
10.13722/j.cnki.jrme.2019.0895
中图分类号：
学科分类号：
摘要：
In order to investigate the stress state effect on water retention and deformation characteristics of expansive soil. Considering the overburden pressure, a soil-water characteristics curve(SWCC) model of expansive soil is carried out. Furthermore, the equation-fitting process of the proposed model under the different one-dimensional overburden pressure is analyzed. Results show that: (1) The moisture content in Nanyang expansive soil displays a regular change and bimodal characteristics wile matrix suction changes. With the increase of overburden pressure, the water-holding capacity of expansive soil decreases. The boundary effect II is significantly prolonged at 200 kPa overburden pressure. (2) The pore ratio of the soil decreases with the increase of overburden pressure and matric suction. The contribution of pore shrinkage caused by overburden pressure is 2.12 times as much as that caused by matric suction. Under the stress, the loss of void water caused by overburden pressure dominates volume shrinkage in the dehumidification process of expansive soil. (3) Based on the segmentation, the Fredlund-Xing equation is improved by using the proposed bimodal SWCC model to fit the data of Nanyang expansive soil. Fitting parameters a1 and n1 can effectively reflect the characteristic variation of SWCC1 under different overburden pressure. The influence of overburden pressure is weakened in the stage of SWCC2. The relationship between each parameter and overburden pressure is not obvious. The research gives references for the quantitative characterization of the hydraulic-mechanical coupling effect of expansive soil, as well as the study of bimodal characteristics SWCC models. © 2020, Science Press. All right reserved.
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页码：3067 / 3075
页数：8
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