岩土材料特性相关塑性位势理论  

Property-dependent plastic potential theory for geomaterials

作　　者：李学丰[1,2] 孔亮[3] 黄茂松[2] 

机构地区：[1]宁夏大学固体力学研究所,宁夏银川750021 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]青岛理工大学理学院,山东青岛266033

出　　处：《岩土工程学报》2013年第9期1722-1729,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51368050);山东省自然科学杰出青年基金项目(JQ201017);2013宁夏自治区科技支撑计划项目;宁夏自治区自然科学基金重点项目(NZ13001)

摘　　要：针对传统塑性位势理论因采用连续性、均匀性与各向同性等基本假定导致其应用于岩土材料导致的局限性,根据砂土细观物理特性可以用宏观组构张量来描述的特点,统一考虑各向同性与各向异性,把应变分配法则和材料特性联系起来,建立了岩土材料特性相关的塑性位势理论。该理论塑性应变增量的分量方向和应力分量方向相同,但是塑性应变增量的大小与3个因素相关,即塑性因子、组构各向异性程度和组构与主应力方向的几何关系。建立的位势理论不但可以描述岩土材料在主应力轴固定条件下应变增量的各向异性分配关系,而且可以描述主应力旋转条件下应变增量的大小和方向变化规律。采用能量转换关系证明了塑性应变增量的大小的变化规律,与现有的非共轴塑性理论相比,建立的位势理论应用范围更广、物理意义更清晰。Aiming at the application defects of the traditional potential theory to geomaterials,caused by the basic assumptions such as continuity,homogeneity and isotropy,the property-dependent plastic potential theory for geomaterials is proposed by linking the strain distribution law with the material properties.The new theory is based on the physical properties in the microscopic aspects of sand described by the fabric with isotropic and anisotropic together.According to the proposed theory,the component direction of the plastic strain increment is consistent with that of the stress,but the value is the function of loading stress,degree of fabric anisotropy and geometric relationship between fabric and stress.Therefore the proposed theory can describe the anisotropic distribution of the plastic strain increment under the fixed principal stress and the values and direction of the plastic strain increment under the rotational principal stress.The energy conversion relationship is used to analyze the variation of the plastic strain increment.Compared with the existing non-coaxial plasticity theory,the proposed potential theory own a wider application and a clearer physical meaning.

关 键 词：塑性位势理论 非共轴 细观结构 材料特性相关 砂土 

分 类 号：TU443[建筑科学—岩土工程]