考虑抗拉强度剪断的非饱和土无限边坡稳定性分析

李梦姿; 蔡国庆; 李昊; 杨贝贝; 赵成刚

doi:10.11779/CJGE202004013

考虑抗拉强度剪断的非饱和土无限边坡稳定性分析 English Version

李梦姿^{1, 2,},
蔡国庆^{1, 2, ,},
李昊³,
杨贝贝⁴,
赵成刚^{1, 2}

1.
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
4.
北京城建设计发展集团股份有限公司郑州分公司,河南　郑州　450000

基金项目:

国家自然科学基金项目 51722802

国家自然科学基金项目 U1834206

国家自然科学基金项目 51678041

河南省交通运输厅科技计划项目 2017B4

详细信息

作者简介:
李梦姿(1992—),女,博士研究生,主要从事非饱和土力学相关研究工作。E-mail: mzli118@163.com

通讯作者:
蔡国庆, E-mail: guoqing.cai@bjtu.edu.cn

中图分类号: TU432
计量
- 文章访问数: 355
- HTML全文浏览量: 52
- PDF下载量: 274
出版历程
- 收稿日期: 2019-03-14
- 网络出版日期: 2022-12-07
- 刊出日期: 2020-03-31

Stability of infinite unsaturated soil slopes with tensile strength cut-off

LI Meng-zi^{1, 2,},
CAI Guo-qing^{1, 2, ,},
LI Hao³,
YANG Bei-bei⁴,
ZHAO Cheng-gang^{1, 2}

1.
Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China
2.
School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China
3.
Bureau of Transport of Henan Province, Zhengzhou 450003, China
4.
Zhengzhou Branch of Beijing Urban Construction Design& Development Group Co., Ltd., Zhengzhou 450000, China

摘要

摘要: 基于Fredlund强度理论提出了抗拉强度包线部分截断的非饱和土非线性强度准则（C-F准则）。该准则允许土体破坏过程中产生剪切破碎。然后建立无限边坡在稳定渗流作用下,考虑抗拉强度部分剪断的无限边坡稳定性分析方法框架,给出非线性强度包线下安全系数的求解方法。该方法可以考虑抗拉强度部分剪断和渗流作用对边坡稳定性的影响规律。分析结果表明,C-F准则较Fredlund强度准则所得安全系数会有降低,对渗流高陡非饱和土边坡稳定性分析的影响会更加显著。
- 非饱和土 /
- 无限边坡 /
- 抗拉强度 /
- 剪断
Abstract: Based on the Fredlund strength theory, a nonlinear strength criterion for unsaturated soils is proposed. The tensile strength envelope of the Fredlund strength theory as a result of extrapolation of compressive tests into the tensile regime is partially truncated or eliminated in the new strength criterion. The new tensile strength cut-off criterion (C-F criterion) allows to construct the failure mechanisms including rupture mode and shear deformation mode. Then a generalized framework for the stability of infinite slopes under steady unsaturated seepage conditions is put forward using the C-F criterion, and a uniform expression for the safety factor under nonlinear strength criterion is given. The influences of tensile strength cut-off and seepage on slope stability can be considered. The results show that the stability factors for infinite slopes in unsaturated soils with tensile strength cut-off are reduced compared to those based on the Fredlund strength envelope, with the largest drop for steep slopes particularly subjected to heavy rainfall infiltration.
- unsaturated soil /
- infinite slope /
- tensile strength /
- cut-off

HTML全文

图 1 平面应变C-F准则

Figure 1. Strength envelope of C-F criterion

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图 2 C-F准则截面（吸力恒定）

Figure 2. Cross section of C-F criterion (constant matrix suction)

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图 3 无限斜坡模型示意图

Figure 3. Schematic diagram for shallow infinite slope model

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图 4 土水特征曲线

Figure 4. Soil-water characteristic curves for sand, silt and clay

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图 5 表观黏聚力分布

Figure 5. Apparent cohesion profiles under various steady seepages

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图 6 3种土安全系数分布

Figure 6. Safety factor profiles of C-F criterion and Fredlund strength criterion for sand, silt and clay

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图 7 不同渗流的安全系数分布

Figure 7. Safety factor profiles of clay slope for C-F criterion and Fredlund strength criterion with various steady seepage conditions

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图 8 坡角的影响

Figure 8. Safety factors for C-F criterion and Fredlund strength criterion under different slope angles

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表 1 土的物理力学参数

Table 1 mechanical and hydrologic parameters of soils

土类 n α c′ ϕ′

砂土 4 0.2 4 33
粉土 3 0.05 8 28
黏性土 2 0.005 25 12

下载: 导出CSV

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