双孔结构非饱和红黏土土水特征曲线模型

蔡国庆; 韩博文; 王亚南; 江天; 谢琳; 张策

doi:10.11779/CJGE2022S1001

双孔结构非饱和红黏土土水特征曲线模型 English Version

蔡国庆^{1, 2,},
韩博文¹,
王亚南¹,
江天¹,
谢琳³,
张策¹

1.
北京交通大学城市地下工程教育部重点实验室, 北京 100044
2.
北京交通大学土木建筑工程学院, 北京 100044
3.
河南省交通运输厅, 河南郑州 450003

基金项目:

中央高校基本科研业务费项目 2021JBZ111

国家自然科学基金项目 U2034204

国家自然科学基金项目 52078031

北京市自然科学基金项目 8202038

江苏省隧道与地下工程技术研究中心开放基金项目 2021-SDJJ-04

详细信息

作者简介:
蔡国庆(1983—)，男，博士，教授，主要从事非饱和土力学及土体多场耦合理论方面的研究。E-mail: guoqing.cai@bjtu.edu.cn

中图分类号: TU443
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- 文章访问数: 181
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出版历程
- 收稿日期: 2022-09-24
- 网络出版日期: 2023-02-06
- 刊出日期: 2022-11-30

SWCC model for double-pore structured unsaturated clay

1.
Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing 100044, China
2.
School of Civil Engineering and Architecture, Beijing JiaoTong University, Beijing 100044, China
3.
Henan Provincial Department of Transportation, Zhengzhou 450003, China

摘要

摘要: 为了真实反映土体内部双孔结构和变形对土持水特性的共同影响，推导建立了考虑变形的双孔结构非饱和土土水特征曲线模型。模型提出以双孔土水特征曲线中的“相接点”作为“双孔”结构非饱和土大小孔隙尺度分界点，并针对不同区间的土水特征曲线分别建立方程。在各分段方程中引入体变参数用来反映不同初始孔隙比下SWCC的变形。采用桂林红黏土压实样，在全吸力范围内开展了土水特征曲线试验，在各级吸力平衡后对土样进行压汞试验，对所建立模型进行验证。结果表明，所建立考虑双孔结构非饱和土土水特征曲线模型对红黏土干化与湿化过程均具有良好的适用性和良好的预测效果，可以反映不同初始孔隙比和不同结构土样在相同水力路径下的水力行为。
- 非饱和土 /
- 土水特征曲线 /
- 双孔结构 /
- 体变 /
- 相接点
Abstract: Some mercury intrusion test results show that the soils using the compaction sample preparation method usually present a typical double-pore micro structure, while the existing unsaturated SWCC models are mostly directed to single-pore structural soils. In order to reflect the double-pore structure inside the soils and the joint effects of deformation on water-holding performance, a unsaturated SWCC model for the double-pore structure considering deformation is proposed and verified through experiments. The "junction point" in the double-pore SWCC is regarded as the boundary point of different pore sizes of the double-pore structured unsaturated soils, and equations for the SWCC of different sections are established. The parameter is introduced in the segment equation to reflect the influences of the deformation. According to the compacted samples of Guilin lateritic clay, the SWCC tests in the full suction range are carried out based on the shaft translation technique, the filter paper method and the saturated salt solution steam balance method. The model parameters are calibrated, and the proposed model is verified.
- unsaturated soil /
- soil-water characteristic curve /
- double porosity soil /
- deformation /
- junction point

HTML全文

图 1 SWCC干化试验拟合曲线

Figure 1. Fitting curves of SWCCs in drying tests

下载: 全尺寸图片幻灯片

图 2 压实土干化试验结果预测（e₀=1.7）

Figure 2. Prediction of compacted soils in drying tests (e₀=1.7)

下载: 全尺寸图片幻灯片

图 3 不同初始孔隙比的压实土土水特征曲线对比（干化）

Figure 3. SWCCs of compacted soils with different initial void ratios (drying)

下载: 全尺寸图片幻灯片

图 4 桂林红黏土-压实土干化试验参数标定曲线

Figure 4. Data fitting of compacted soils in drying tests

下载: 全尺寸图片幻灯片

图 5 压实土湿化试验结果预测（e₀=1.3）

Figure 5. Prediction of compacted soils in wetting tests (e₀=1.3)

下载: 全尺寸图片幻灯片

图 6 不同初始孔隙比压实土土水特征曲线对比（湿化）

Figure 6. SWCCs of compacted soils with different initial void ratios (wetting)

下载: 全尺寸图片幻灯片

表 1 压实土干化试验参数标定(e₀=1.5)

Table 1 The parameter calibration of compacted soil in drying test (e₀=1.5)

大孔隙SWCC标定参数	a	m	n	$\zeta$	R²
大孔隙SWCC标定参数	30.119	0.18539	6.3635	0.38	0.999

小孔隙SWCC标定参数	$a'$	$m'$	$n'$	$\zeta '$	R²
小孔隙SWCC标定参数	17930	1.55863	2.3590	0.95	0.994

下载: 导出CSV

表 2 压实土干化试验参数标定(e₀=1.5)

Table 2 Parameter calibration of compacted soils in drying tests (e₀=1.5)

大孔隙SWCC标定参数	a	m	n	$\zeta$	R²
大孔隙SWCC标定参数	21.57	0.3258	2.9294	0.90	0.979

小孔隙SWCC标定参数	$a'$	$m'$	$n'$	$\zeta '$	R²
小孔隙SWCC标定参数	17893	1.65484	2.0601	0.90	0.996

下载: 导出CSV

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