CAJ | 학술논문

针对传统本构理论无法描述土体单剪试验非共轴变形的不足，采用非共轴修正模型进行改进。模型基于材料状态相关临界状态理论，采用宏-细观结合的方法，将1个新的各向异性状态变量引入本构模型来描述砂土的各向异性。考虑细观组构张量和应力张量的几何关系的变化，模型可以描述砂土在主应力轴旋转条件下材料状态的变化，材料状态变化直接导致模型的硬化规律和剪胀性发生变化，因此，模型可以描述该条件下原生向异性对砂土变形的影响。引入非共轴理论对本构模型进行修正，建立了三维非共轴各向异性模型。单剪试验的加载条件会造成主应力轴相对土体沉积面发生旋转，修正模型不但能够描述砂土在主应力轴旋转条件下其原生各向异性对变形的影响，而且可以描述主应力轴旋转造成的应力诱发各向异性对土体变形的影响，因此，该模型能够对整个单剪试验的变形规律进行描述，而且物理意义清晰。通过铝棒堆积体和Toyoura砂单剪试验验证表明，非共轴修正各向异性模型能对单剪试验的整个变形过程进行较好的模拟。
침대전통본구이론무법묘술토체단전시험비공축변형적불족，채용비공축수정모형진행개진。모형기우재료상태상관림계상태이론，채용굉-세관결합적방법，장1개신적각향이성상태변량인입본구모형래묘술사토적각향이성。고필세관조구장량화응력장량적궤하관계적변화，모형가이묘술사토재주응력축선전조건하재료상태적변화，재료상태변화직접도치모형적경화규률화전창성발생변화，인차，모형가이묘술해조건하원생향이성대사토변형적영향。인입비공축이론대본구모형진행수정，건립료삼유비공축각향이성모형。단전시험적가재조건회조성주응력축상대토체침적면발생선전，수정모형불단능구묘술사토재주응력축선전조건하기원생각향이성대변형적영향，이차가이묘술주응력축선전조성적응력유발각향이성대토체변형적영향，인차，해모형능구대정개단전시험적변형규률진행묘술，이차물리의의청석。통과려봉퇴적체화Toyoura사단전시험험증표명，비공축수정각향이성모형능대단전시험적정개변형과정진행교호적모의。
Aiming at the shortcomings of traditional constitutive theory failure to describe the non-coaxial deformation of soil for simple shear test, a constitutive model amended with non-coaxial plasticity theory is employed to improve it. Based on the critical state and state-dependent theories, with the method of macro-meso-incorporation, a novel anisotropy state variable is introduced in the model to describe the anisotropy of sand. In view of the geometric relationship of meso-fabric and stress state, the state of sand changes in the principal stress axes rotation condition, and the dilatancy and hardening law of model is the function of sand state, so the model can describe the effect of inherently anisotropy on deformation of sand in this condition. The non-coaxial plasticity theory employed to amend the constitutive model, a three-dimensional non-coaxial model for anisotropic sand is presented. The loading conditions of simple shear test causes the rotation of principal stress axis relative to the soil deposition direction; the amended constitutive model can describe the effect of inherently anisotropy and stress-induced anisotropy on deformation characters under the principal stress rotation conditions;so the amended model can describe the whole characters of simple shear test with clear physical meaning. The verification with simple shear test results of rod mass and Toyoura sand shows that the amended model can well simulate deformation properties.