Mechanism of progressive failure in river dike during infiltration and overflow and its prediction

河堤渗溢过程渐进破坏机理及预测

• 批准号: 17560441
• 负责人: UZUOKA Ryosuke
• 金额: $ 2.46万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17560441/
• 关键词: geotechnical engineering; land protection; flood; disaster reduction; disaster prevention; river dike; infiltration; progressive failure

The purpose of this study is to clarify the mechanism of progressive failure of river dike during the infiltration and overflow of river water. First, infiltration-shear tests during of unsaturated soil from actual river dike were performed in order to propose a constitutive model which can reproduce shear deformation during infiltration. As the results of the infiltration-shear tests, large shear strain was produced during infiltration under initial shear condition. An elasto-plastic constitutive model was newly proposed to reproduce the results of the infiltration-shear tests. The proposed constitutive model is based on super/sub loading surface Cam-Clay model and it has a modified evolution law which is a function of suction as an internal variable. The proposed model reproduced the increase in large shear strain during infiltration in the simulation of the infiltration-shear tests. Second, dynamic soil-water-air coupled analysis method at finite strain was developed. Static self-weight analyses, quasi-static consolidation analyses, dynamic consolidation analyses and quasi-static leaking flow analyses of unsaturated soil were performed in order to verify the developed numerical code. Preliminary analyses with elastic constitutive model showed that the proposed "aerial element" which has water retention characteristics of air and small stiffness could be used for direct modeling of river water. Although further investigations into convection term are needed, aerial element can be useful for the interaction analysis between overflow water and soil embankment. Third, progressive failure of river dike during infiltration of river water was simulated with the proposed constitutive model and numerical code. Although further investigations into implicit integration of stress are needed, the numerical results showed that seepage flow appeared at the landside toe of the dike and the slope became unstable at the waterside toe of the dike when the river level rose.

本研究的目的是阐明河水入渗和溢流过程中河堤渐进破坏的机制。首先，对实际河堤的非饱和土进行了入渗剪切试验，以提出一种能够再现入渗过程中剪切变形的本构模型。渗透剪切试验结果表明，在初始剪切条件下，渗透过程中产生了较大的剪切应变。新提出了弹塑性本构模型来重现渗透剪切试验的结果。所提出的本构模型基于超/次载荷表面Cam-Clay模型，并且具有修正的演化定律，该演化定律是吸力作为内部变量的函数。所提出的模型在渗透剪切试验的模拟中再现了渗透过程中大剪切应变的增加。其次，开发了有限应变下的动态土-水-空气耦合分析方法。为了验证所开发的数值规范，进行了非饱和土的静态自重分析、准静态固结分析、动力固结分析和准静态渗流分析。弹性本构模型的初步分析表明，所提出的“空气单元”具有空气的保水特性和较小的刚度，可用于河水的直接建模。尽管需要对对流项进行进一步研究，但空中元素可用于溢流水与土堤之间的相互作用分析。第三，用所提出的本构模型和数值规范模拟了河水渗透过程中河堤的渐进破坏。尽管还需要进一步研究隐式应力积分，但数值结果表明，当河流水位上升时，堤岸陆侧趾部出现渗流，堤岸水侧趾部边坡变得不稳定。

项目成果

Finite element analysis for dynamic finite deformation in unsaturated soil

非饱和土动态有限变形有限元分析

• 发表时间: 2007
• 期刊: Proc. 12th Japan National Conf. on Computational Engineering and Science 12
• 作者: Uzuoka;R.;Kamura;A.;Sento;N. and Kazama;M.
• 通讯作者: M.

鳴瀬川不飽和堤防土を用いた中空ねじり試験機による浸水試験

使用成濑川非饱和路堤土，使用空心扭转试验机进行洪水试验

• 发表时间: 2006
• 期刊: 土木学会東北支部技術研究発表会
• 作者: 渦岡良介;加村晃良;他2名;栗原崇
• 通讯作者: 栗原崇

不飽和地盤の動的・有限変形問題に対する有限要素解析

非饱和地基动力及有限变形问题的有限元分析

• 发表时间: 2007
• 期刊: 第12回計算工学講演会論文集 12
• 作者: 渦岡良介、加村晃良;他2名
• 通讯作者: 他2名

初期せん断応力を受けた堤防土の不飽和浸水時の変形特性

非饱和洪水初始剪应力作用下路堤土的变形特征

• 发表时间: 2007
• 期刊: 第42回地盤工学研究発表会 平成19年度発表講演集 42
• 作者: 栗原崇、渦岡良介;他2名
• 通讯作者: 他2名

多孔質・有限変形理論に基づいた不飽和地盤の動的有限要素解析

基于多孔/有限变形理论的非饱和地基动力有限元分析

• 发表时间: 2007
• 期刊: 第42回地盤工学研究発表会 平成19年度発表講演集 42
• 作者: 加村晃良、渦岡良介;他2名
• 通讯作者: 他2名