| 非饱和土粒间吸力研究的若干思考和进展 |
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| 引用本文： | 张鹏程,汤连生,邓钟尉,姜力群.非饱和土粒间吸力研究的若干思考和进展[J].水文地质工程地质,2012,39(2):30-36. |
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| 作者姓名： | 张鹏程 汤连生 邓钟尉 姜力群 |
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| 作者单位： | （1. 中山大学应用力学与工程系， 广州 510275；2. 广州市城市规划勘测设计研究院， 广州 510060；3. 中山大学地球科学系， 广州 510275） |
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| 基金项目： | 国家自然科学基金资助项目(40872205);全国高等学校博士学科专项科研基金资助项目(20070558032);广东省科技计划项目资助(2008B030303009) |
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| 摘 要： | 非饱和土粒间吸力是建立非饱和土有效应力原理和抗剪强度理论的基础前提，从各力的本质、概念、大小等不同角度出发，对目前非饱和土研究中常见的几种吸力进行了详细地对比和分析。基质吸力表示土壤吸水的趋势，强调的是土颗粒与水之间的相互作用，并非土颗粒间的相互作用，与有效应力概念的本质不符，是Bishop和Fredlund强度理论中分别存在着物理意义不明确参数x和φb的根本原因；广义吸力虽然考虑了结构吸力的作用，但仍将基质吸力作为有效应力的一部分，使原本“实用、简化”的目标更加复杂化；附加内压力将基质吸力以及表面张力的作用进行叠加，存在力作用大小上的重复，同时未考虑结构吸力的作用；张力吸力将表面张力沿两土颗粒连线方向的分量——张力吸力和基质吸力进行叠加，一是仍将基质吸力作为有效应力的一部分，二是同样未考虑结构吸力的作用；粒间吸力（湿吸力和结构吸力）考虑了因土体结构性引起的结构吸力作用，同时也考虑了气液界面上收缩膜的效应——湿吸力的作用，基于粒间吸力的非饱和土有效应力及强度理论不仅符合有效应力定义的本质，而且合理地解释了非饱和土中诸如收缩膜张力的方向性、土中应力概念的平均性、土体物理本质的唯一性、随含水率变化的连续性以及对不同类型土的适应性等众多现象。因此，从粒间吸力的角度出发来研究非饱和土的有效应力原理是正确、可行的。
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| 关 键 词： | 非饱和土,,粒间吸力,,基质吸力,,广义吸力,,张力吸力," target="_blank">,,COLOR:,#000000,,FONT-SIZE:,9pt">非饱和土,,粒间吸力,,基质吸力,,广义吸力,,张力吸力, |
| 收稿时间： | 2011-07-11 |
| 修稿时间： | 2011-08-29 |
Development and thinking of research on the suction between grains of unsaturated soils |
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| ZHANG Peng-cheng
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TANG Lian-sheng
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DENG Zhong-wei
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JIANG Li-qun.Development and thinking of research on the suction between grains of unsaturated soils[J].Hydrogeology and Engineering Geology,2012,39(2):30-36. |
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| Authors: | ZHANG Peng-cheng TANG Lian-sheng DENG Zhong-wei JIANG Li-qun |
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| Institution: | 1.Department of Applied Mechanics and Engineering,Sun Yat-Sen University,Guangzhou 510275,China;2.Guangzhou Urban Planning Survey and Design Institute,Guangzhou 510060,China;3.Department of Earth Sciences,Sun Yat-Sen University, Guangzhou 510275,China) |
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| Abstract: | Suction between grains of unsaturated soil is the foundation of establishing theory of unsaturated soil effective stress and shear strength.From the essence,concept,size of all suctions,several common suctions in research of unsaturated soil at present are compared and analyzed in detail this paper.Matrix suction represents the trend of absorbing water of soil,emphasizing the interaction between soil grains and water,not the interaction among soil grains.There are parameters x and φb in Bishop and Fredlund’s theory of strength,which do not have clear physical meaning,because their theories are in disagreement with the essential concept of effective stress.Though generalized suction involves the effect of structure suction,it lets matrix suction be a part of effective stress,making it practical,simple and more complicated.Additional inner pressure superposes the effect of matrix suction on surface tension suction,so reduplication of suction effect exists,and it doesn’t consider the effect of structure suction.Tension suction superposes tension suction on matrix suction,that is,two kind of suctions are component of surface tension suction along two grains connective direction.On the one hand,it still makes matrix suction a part of effective stress,on the other hand,it also doesn’t consider the effect of structure suction.Suction between grains(wet suction and structure suction) considers the effect of structure suction because of soil structure,at the same time,it also considers the effect of shrink film of gas-liquid interface,namely the effect of wet suction.Unsaturated soil effective stress theory and shear strength theory based on suction between grains are not only in agreement with the essential definition of effective stress,but also successfully explain so many features of unsaturated soil such as the directivity of shrink film tension,the average of concept of stress existing in soil,the uniqueness of soil physical essence,the continuity with the change in water content and the adaptability for different kinds of unsaturated soil.Therefore,studying effective stress theory of unsaturated soil from the suction between grains is correct and feasible. |
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| Keywords: | unsaturated soil suction between grains matrix suction generalized suction tension suction |
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