结构性黏土的原位刚度衰减规律及数学表征

doi:10.16285/j.rsm.2021.1358

岩土力学 ›› 2022, Vol. 43 ›› Issue (S1): 410-418.doi: 10.16285/j.rsm.2021.1358

结构性黏土的原位刚度衰减规律及数学表征

安然^{1, 2}，孔令伟^{1, 3}，师文卓^{1, 3}，郭爱国^{1, 3}，张先伟^{1, 3}

1. 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室，湖北武汉 430071；2. 武汉科技大学城市建设学院，湖北武汉 430081； 3. 中国科学院大学，北京 100049

收稿日期:2021-08-18 修回日期:2021-09-14 出版日期:2022-06-30 发布日期:2022-07-15
通讯作者: 孔令伟，男，1967年生，博士，研究员，博士生导师，主要从事特殊土的力学特性与灾害防治技术方面的研究。E-mail: lwkong@whrsm.ac.cn E-mail:anran@wust.edu.cn
作者简介:安然，男，1992年生，博士，讲师，硕士生导师，主要从事特殊土土力学与环境土工程特性方面的研究。
基金资助:
国家自然科学基金（No.41877281，No.12102312，No.41972285）。

In-situ stiffness decay characteristics and its numerical descriptions of structured clays

AN Ran^{1, 2}, KONG Ling-wei^{1, 3}, SHI Wen-zhuo^{1, 3}, GUO Ai-guo^{1, 3}, ZHANG Xian-wei^{1, 3}

1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China; 2. School of Urban Construction, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China; 3. University of Chinese Academy of Sciences, Beijing, 100049, China

Received:2021-08-18 Revised:2021-09-14 Online:2022-06-30 Published:2022-07-15
Supported by:
This work was supported by the National Natural Science Foundation of China(41877281, 12102312, 41972285).

摘要/Abstract

摘要： 湛江组黏土作为一种高强度、高灵敏度的结构性土，其力学特性易受取样扰动的影响。通过在典型结构性黏土地层中开展自钻旁压试验（SBPT）和地震扁铲试验（SDMT），获取了土体原位剪切模量−剪应变衰减曲线（G-g 曲线），并采用Stokoe模型表征其归一化刚度衰减性状。结果表明：通过SDMT测得的地震波波速V_s计算了小应变剪切模量G₀，基于SBPT结果的非线性分析推导出土体的切线剪切模量G_t，结合G₀和G_t进而获取了完整的原位刚度衰减曲线；不同深度处的土体原位剪切模量G随剪应变g 增加均呈双曲线形的衰减规律，证明结构性黏土的力学性能具有非线性特征；随着土层深度增加，结构性黏土的原位刚度参数在g ≤10⁻³%条件下呈增大趋势，在g >1%条件下几乎不变；归一化的原位G-g 曲线与Stokoe模型计算结果基本吻合，说明采用Stokoe模型能够准确、合理地描述土体原位刚度衰减特征。该研究可为湛江组黏土地层的岩土工程建设提供设计参数，也可为类似地层的刚度分析提供参考。

关键词: 结构性黏土, 刚度衰减特征, 剪切模量, 原位试验, Stokoe模型

Abstract:

The Zhanjiang clay is a typical structured soil with high strength and sensitivity, and its mechanical properties are easily affected by sampling disturbance. Based on the self-boring pressuremeter tests (SBPT) and seismic dilatometer tests (SDMT) in the typical structured clay stratum, the in-situ stiffness decay curves are obtained. Furthermore, the Stokoe model is used to describe the normalized stiffness decay behaviors. Results show that the in-situ stiffness decay curve can be obtained by combining the tangential shear modulus G_t from SBPT with the small-strain shear modulus G₀ from seismic wave velocity V_s calculated by SDMT. The in-situ stiffness decay curves of structured clays at different depths have a declined trend with a hyperbolic type with the increasing strain levels, which proves that the mechanical properties of structured clays exhibit nonlinear characteristics. With the increase of depth, the in-situ stiffness parameters tend to increase under the condition of shear strain less than 10⁻³%, while they almost remain unchanged when the shear strain is larger than 1%. The normalized G-g decay curves obtained from the in-situ tests are in good agreement with the fitting curves from the Stokoe model, indicating that the numerical model could accurately describe the in-situ stiffness decay characteristics of structured clays. This study provides the design parameters for geotechnical engineering constructions of structured clays in Zhanjiang and an important reference for similar formations.

Key words: structured clay, stiffness decay characteristics, shear modulus, in-situ test, Stokoe model

中图分类号:

TU442

安然, 孔令伟, 师文卓, 郭爱国, 张先伟, . 结构性黏土的原位刚度衰减规律及数学表征[J]. 岩土力学, 2022, 43(S1): 410-418.

AN Ran, KONG Ling-wei, SHI Wen-zhuo, GUO Ai-guo, ZHANG Xian-wei, . In-situ stiffness decay characteristics and its numerical descriptions of structured clays[J]. Rock and Soil Mechanics, 2022, 43(S1): 410-418.

参考文献

相关文章 15

[1]	焦钰祺, 贺林林, 梁越, 刘旭菲, . 考虑结构性黏土应变软化效应的桩靴竖向承载特性研究[J]. 岩土力学, 2022, 43(5): 1374-1382.
[2]	王斌, 韩幽铭, 周欣, 陈成, 张先伟, 桂蕾, . 太湖湖相黏土层剪切模量衰减特性的原位测试研究[J]. 岩土力学, 2021, 42(7): 2031-2040.
[3]	舒荣军, 孔令伟, 师文卓, 刘炳恒, 黎澄生, . 湛江结构性黏土自钻旁压试验的加载速率效应[J]. 岩土力学, 2021, 42(6): 1557-1567.
[4]	侯振坤, 唐孟雄, 胡贺松, 黎剑华, 张树文, 徐晓斌, 刘春林, . 随钻跟管桩竖向承载性能原位试验与室内物理模拟试验对比研究[J]. 岩土力学, 2021, 42(2): 419-429.
[5]	王东坡, 何启维, 刘彦辉, 温继伟, 李伟, . 滚石冲击改进型开口帘式网耗能机制研究[J]. 岩土力学, 2021, 42(12): 3356-3365.
[6]	周跃峰, 杨哲, 饶锡保, 肖国强, 周黎明. 不同含水率下黏土弹性参数的弯曲−伸展元试验研究[J]. 岩土力学, 2020, 41(S1): 387-393.
[7]	朱楠, 刘春原, 赵献辉, 王文静, . 不同应力路径下K0固结结构性黏土微观结构特征试验研究[J]. 岩土力学, 2020, 41(6): 1899-1910.
[8]	梁珂, 陈国兴, 杭天柱, 刘抗, 何杨, . 砂类土最大动剪切模量的新预测模型[J]. 岩土力学, 2020, 41(6): 1963-1970.
[9]	梁珂, 陈国兴, 刘抗, 王彦臻, . 饱和珊瑚砂最大动剪切模量的循环加载衰退特性及预测模型[J]. 岩土力学, 2020, 41(2): 601-611.
[10]	吴琪, 刘抗, 郭启洲, 赵凯, 陈国兴, . 基于二元介质模型的砂类土小应变剪切模量评价方法[J]. 岩土力学, 2020, 41(11): 3641-3650.
[11]	梁珂, 何杨, 陈国兴, . 南沙珊瑚砂的动剪切模量和阻尼比特性试验研究[J]. 岩土力学, 2020, 41(1): 23-31.
[12]	杨文保, 吴琪, 陈国兴, . 长江入海口原状土动剪切模量预测方法探究[J]. 岩土力学, 2019, 40(10): 3889-3896.
[13]	盛云锋, 陈远, 周伟, 马刚, 常晓林, . 基于改进动剪切模量模型的堆石坝动力响应分析[J]. 岩土力学, 2018, 39(S2): 405-414.
[14]	张炜，李亚，周松望，蒋正波，吴非，梁文洲，. 南海北部区域黏土循环动力特性试验研究[J]. , 2018, 39(7): 2413-2423.
[15]	孔纲强，李辉，王忠涛，文磊,. 透明砂土与天然砂土动力特性对比[J]. , 2018, 39(6): 1935-1940.

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed

结构性黏土的原位刚度衰减规律及数学表征

In-situ stiffness decay characteristics and its numerical descriptions of structured clays

PDF (Chinese)

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 15

Metrics

本文评价

推荐阅读 10