静动荷载作用下海洋软黏土刚度弱化特性研究

陆素洁; 童俊豪; 潘坤; 袁宗浩; 潘晓东; 史吏; 何奔

doi:10.11779/CJGE2020S1023

静动荷载作用下海洋软黏土刚度弱化特性研究 English Version

陆素洁^1,,
童俊豪²,
潘坤^2, ,,
袁宗浩²,
潘晓东²,
史吏²,
何奔¹

1.
中国电建集团华东勘测设计研究院有限公司,浙江　杭州　311122
2.
浙江工业大学建筑工程学院,浙江　杭州　310023

基金项目:

国家自然科学基金项目 51909249

详细信息

作者简介:
陆素洁（1982— ）,女,福建古田人,高级工程师,主要从事水工结构设计研究。E-mail：lu_sj@ecidi.com

通讯作者:
潘坤, E-mail：pk2018@zju.edu.cn

中图分类号: TU411
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出版历程
- 收稿日期: 2020-06-01
- 网络出版日期: 2022-12-07
- 刊出日期: 2020-10-31

Stiffness degradation of marine soft clay under monotonic and cyclic loadings

1.
POWERCHINA Huadong Engineering Corporation Limited, Hangzhou 311122, China
2.
College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310023, China

摘要

摘要: 利用动三轴联合弯曲元测试系统对嘉兴原状海洋软黏土进行了一系列不排水条件下单调和循环三轴试验,分析静动荷载作用对正常固结软黏土的小应变剪切模量及刚度弱化特性的影响。试验结果表明,土体小应变剪切模量在单调荷载作用下先减小后增大,在循环荷载作用时则逐渐减小并最终保持稳定。在中到大应变下,饱和软土归一化动模量随循环单幅应变发展不断减小,且其值相较于单调剪切时的割线模量略大。研究发现,土体动模量弱化规律与动荷载作用下的小应变刚度特性密切相关,在不同固结围压和循环加载条件下表现出很好的一致性。研究结果可为该区域海洋构筑物设计提供依据,也可供其他同类型工程借鉴。
- 海洋软黏土 /
- 单调荷载 /
- 循环荷载 /
- 小应变剪切模量 /
- 刚度弱化
Abstract: A series of undrained monotonic and cyclic triaxial tests are conducted on Jiaxing intact marine soft clay by using a testing system combined with triaxial apparatus and bender element to investigate the small strain shear modulus and stiffness degradation of isotropically consolidated soft clay. The results indicate that the small strain shear modulus decreases and then increases under monotonic loading, but it tends to decrease continuously under cyclic loading. At medium to large strains, the normalized equivalent modulus of saturated soft clay decreases gradually with the development of single-amplitude cyclic strain with a larger degradation rate than the monotonic secant modulus. In addition, a fairly unique relationship exists between the cyclic degraded stiffness and small strain shear modulus, which is barely affected by the initial confining pressure and cyclic stress condition. The findings obtained in this study can provide the basis for the design of offshore structures in this area, and can also be used as a reference in other engineering projects.
- marine soft clay /
- monotonic loading /
- cyclic loading /
- small strain shear modulus /
- stiffness degradation

HTML全文

图 1 　G_max,0- ${p^{'}}_{0}$ 关系和归一化G_max,0- ${p^{'}}_{0}$ 关系

Figure 1. Relationship between G_max,0 and ${p^{'}}_{0}$ and normalized relationship between G_max,0 and ${p^{'}}_{0}$

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图 2 单调加载下的小应变剪切模量

Figure 2. Small strain shear moduli under monotonic loading

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图 3 割线模量与应变的关系

Figure 3. Secant moduli against axial strain

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图 4 循环加载下的小应变剪切模量

Figure 4. Small strain shear moduli under cyclic loading

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图 5 等价模量及归一化等价模量与应变的关系

Figure 5. Equivalent moduli and normalized equivalent moduli against axial strain

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图 6 循环加载下等价模量与小应变剪切模量的关系

Figure 6. Relationship between equivalent modulus and small strain shear modulus under cyclic loading

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表 1 单调及循环三轴试验

Table 1 Monotonic and cyclic triaxial tests

试验类别	组号	${p^{'}}_{0}$ /kPa	N	CSR
单调试验	Mon1	200	—	—
	Mon2	400	—	—
	Mon3	50	—	—
	Mon4	100	—	—
	Mon5	300	—	—
循环试验	Cyc1	200	130	0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.7, 1.0, 1.35
	Cyc2	400	130	0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.7, 1.0, 1.35
	Cyc3	200	1000	0.5
	Cyc4	200	20	1.0
	Cyc5	400	1000	0.5

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