偏压固结下软黏土循环强度弱化分析及数值模拟

王元战; 雷继超; 李青美; 胡珅榕

doi:10.11779/CJGE201709002

偏压固结下软黏土循环强度弱化分析及数值模拟 English Version

1. 天津大学水利工程仿真与安全国家重点实验室高新船舶与深海开发装备协同创新中心,天津 300072;
2. 中交第一航务工程勘察设计院有限公司,天津 300222

基金项目: 交通运输部交通建设科技项目（2014328224040）; 国家自然科学基金项目（51679166）; 国家自然科学基金创新研究群体科学基金项目（51321065）

详细信息

作者简介:
王元战(1958- ),男,天津人,教授,博导,从事港口海岸与近海结构设计理论和方法、土与结构相互作用、结构振动分析理论和方法等方面的研究工作。E-mail：yzwang@tju.edu.cn。

中图分类号: TU43
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出版历程
- 收稿日期: 2016-06-10
- 发布日期: 2017-09-24

Post-cyclic strength degradation behavior of soft clay under anisotropic consolidation and numerical simulation

1. National Key Laboratory of Water Conservancy Engineering Simulation and Security, Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Tianjin University, Tianjin 300072, China;
2. CCCC First Harbor Engineering Design Institute Co., Ltd., Tianjin 300222, China

摘要

摘要: 在波浪等循环荷载的作用下,近海工程地基中的软黏土会发生强度弱化,影响上部结构的稳定性。以烟台港的淤泥质粉质黏土为研究对象,进行了动、静三轴试验,探讨不同固结静偏应力和不同循环动应力作用下淤泥质粉质黏土的循环强度弱化规律以及土体循环后不排水剪有效应力路径发展规律。通过对土体循环后不排水剪切过程中有效应力路径的分析,发现当动应力比达到0.4后,土体强度弱化趋势加快,临界有效应力比（M）减小,结构发生一定的破坏,并据此探讨了土体强度弱化机理。此外,基于等效超固结理论,在考虑偏压固结使土体初始有效应力提高的前提下,经过理论推导,得出了考虑初始固结静偏应力和循环效应的土体强度弱化公式,并通过试验数据对其进行验证。最后,通过对ABAQUS的二次开发,利用拟静力算法将该公式应用于烟台港数值模型的有限元计算中。
- 软黏土 /
- 循环荷载 /
- 偏压固结 /
- 有效应力路径 /
- 强度弱化 /
- 数值模拟
Abstract: Under the action of cyclic loading of waves, the strength degradation of the soft clay beneath the offshore structures will take place, which will weaken the stability of the upper structure. A series of triaxial tests on silty clay of Yantai Port are carried out to investigate the strength degradation of the soft clay under different anisotropic consolidation stress ratios and different cyclic stress ratios. The behavior of post-cyclic undrained effective stress paths is also studied. Through the analysis of post-cyclic undrained effective stress paths, it is discovered that once the cyclic stress ratio is over 0.4, the trend of strength degradation of soils will accelerate, the critical effective stress ratio M will decrease and there will be some damage of the structure of the clay. The mechanism of strength degradation of clay is discussed. Furthermore, based on the equivalent super consolidation theory, a formula is proposed for the calculation of post-cyclic strength degradation of soils considering the increase of the initial effective stress induced by anisotropic consolidation. The formula is verified by the test results. Finally, through the secondary development of ABAQUS, it is applied to the numerical model of a breakwater in Yantai Port using the quasi-static method.
- soft clay /
- cyclic loading /
- anisotropic consolidation /
- effective stress path /
- strength degradation /
- numerical simulation

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参考文献(15)

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偏压固结下软黏土循环强度弱化分析及数值模拟 English Version

作者简介: 王元战(1958- ),男,天津人,教授,博导,从事港口海岸与近海结构设计理论和方法、土与结构相互作用、结构振动分析理论和方法等方面的研究工作。E-mail：yzwang@tju.edu.cn。

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Post-cyclic strength degradation behavior of soft clay under anisotropic consolidation and numerical simulation

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出版历程

目录

作者简介:
王元战(1958- ),男,天津人,教授,博导,从事港口海岸与近海结构设计理论和方法、土与结构相互作用、结构振动分析理论和方法等方面的研究工作。E-mail：yzwang@tju.edu.cn。