Soil-Water Characteristics of Unsaturated Soil under Vertical Load

doi:10.3969/j.issn.1674-0696.2017.04.12

Abstract

Abstract: Some research statuses of the influence of vertical stress on SWCC (soil-water characteristic curve) were summarized. The basic physical properties of soil samples of a certain building site in Hefei were tested. Compression test of the soil samples under equal vertical load or equal air pressure were completed by FGJ-20 SDSWCC. Interaction between vertical load and unsaturated soil-water characteristics was analyzed according to test results. Results indicate that different vertical loads lead to the difference of soil-water characteristic curves; the influence of vertical load on the soil water characteristic curve gradually reduces with the enhancement of suction; with the increase of vertical load, the parameter a and parameter m increase while the parameter n decreases, and a, m, n are parameters in Fredlund-Xing three-parameter model; the influence of vertical load on soil moisture content is related with the matric suction of soil, and the influence of different suction ranges needs to be considered in actual analysis process; in the condition of equal soil suction, the variation of the water content of soil tends to raise at first and then reduce gradually with the increase of the vertical load.

Key words: geotechnical engineering, unsaturated soil, soil-water characteristic curve, vertical load, moisture content, matric suction

摘要： 总结了竖向应力作用对非饱和土土-水特征曲线影响的部分研究现状。试验得出合肥地区某工地土体基本物理性质指标，并利用FGJ-20型非饱和土固结仪对该土样进行了控制竖向荷载与控制气压力的压缩试验。基于试验结果，对竖向荷载作用下非饱和土土-水特征进行了分析研究。结果表明：竖向荷载不同导致土-水特征曲线产生差异；竖向荷载对土-水特征曲线的影响随着吸力的增大逐渐减弱；Fredlund-Xing三参数模型中参数a，m均随着竖向荷载的增大而逐渐增大，n值则逐渐减小；竖向荷载对土体含水率的影响程度与土体吸力大小有关，实际分析过程中需考虑吸力范围的影响；在吸力不变时，土体含水率的变化量随着竖向荷载的增大呈先增后减的趋势。

关键词: 岩土工程, 非饱和土, 土-水特征曲线, 竖向荷载, 含水率, 基质吸力

CLC Number:

TU43

WEI Song1, 2, 3, DENG Ao1, YAO Zhenxing1, XIAO Shuxia1, 3. Soil-Water Characteristics of Unsaturated Soil under Vertical Load[J]. Journal of Chongqing Jiaotong University(Natural Science), 2017, 36(4): 69-75.

魏松1,2,3，邓奥1，姚振兴1，肖淑霞1,3. 竖向荷载作用下非饱和土土-水特征研究[J]. 重庆交通大学学报（自然科学版）, 2017, 36(4): 69-75.

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