摘要
为了弥补土力学中缺失连续性假设这一重要理论缺陷,在对多个学科中的连续性概念进行系统地梳理考究的基础上,提出了土力学中连续性假设的恰当表述,进而厘清了土的本构模型的概念、种类、属性和建模思路。研究结果表明:连续介质力学和多孔介质流体动力学的连续性假设为土力学的连续性假设提供了有益参考,但都有一定的缺陷;用混合物理论的观点和方法描述土的连续性比较合适,且可以避开在定义孔隙率时遇到的困扰;“连续”是一个相对的概念,当外部特征尺寸远大于介质内部特征尺寸时,就可以把研究对象看作连续介质;现有土的各种本构模型均以连续介质力学为基础,总体上属于唯象模型。阐明了本构关系的概念、种类和建模思路:本构关系是物质宏观性质的数学模型;土的本构模型包括持水、渗水、渗气、传热、屈服、变形、强度、细观结构演化、热力学效应、相变规律等多方面的内容,而不仅限于应力-应变关系;土的本构关系的研究应针对具体土类,抓住主要影响因素,建立解决主要问题的数学模型。
In order to make up for the important theoretical defect of its lack in the soil mechanics,the continuity hypothesis is properly put forward on the basis of systematic reviews and studies on the continuity concept in multiple disciplines,and then the concept,category,attribute and modeling idea of the constitutive model for soils are clarified.The results show that the continuity hypotheses in the continuum mechanics and dynamics of fluids in porous media provide useful references for the continuity hypothesis in soil mechanics,but both have certain defects.The viewpoint and method in the theory of mixtures are suitable for describing the continuity of soils,and it can avoid the difficulties encountered in defining the porosity.The continuity is a relative concept.A research object can be regarded as a continuous medium when the external feature size is much larger than the internal feature size of the medium of which the research object is made.The existing constitutive models for soils are all based on the continuum mechanics and generally belong to phenomenological ones.The concept,category and modeling idea of the constitutive relation are clarified,that is,the constitutive relation is a mathematical model for the macro-properties of substances;The constitutive model for soils includes various aspects such as water retention,water permeability,gas permeability,heat transfer,yield,deformation,strength,meso-structure evolution,thermodynamic effects,phase transformation laws,etc.,not merely limited to stress-strain relationship.For the studies on the constitutive relation of soils,the specific soil category should be highlighted,the main influencing factors should be grasped,and the mathematical model to solve the main problem should be established.
作者
陈正汉
苗强强
郭楠
张昭
CHEN Zhenghan;MIAO Qiangqiang;GUO Nan;ZHANG Zhao(Department of Military Installation,Army Logistics University,Chongqing 401311,China;College of Civil Engineering,Northwest Minzu University,Lanzhou 730030,China;Key Laboratory of Green Engineering Materials and Low-carbon Construction,Gansu Province,Lanzhou 730030,China;College of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Institute of Geotechnical Engineering,Xi’an University of Technology,Xi’an 710048,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第11期2245-2255,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(52168051,42372336,42456202)
西北民族大学高层次人才引进项目
甘肃省绿色工程材料与低碳建造重点实验室开放课题项目
关键词
连续性假设
连续介质力学
多孔介质流体动力学
混合物理论
本构模型
建模思路
continuity hypothesis
continuum mechanics
dynamics of fluids in porous media
theory of mixture
constitutive model
modeling ideas
