CAJ | 학술논문

土体的物理力学特性受到颗粒尺度及其级配的强烈影响，具有显著的颗粒尺度效应。文中采用天然黏土和商品石英砂，制备具有不同颗粒粒径和体分比的一系列三轴抗剪试样，通过不固结不排水和固结不排水三轴抗剪试验，测得了应力应变关系曲线以及剪应力屈服强度，基于试验结果对土体力学特性的颗粒尺度效应进行分析；同时，引入胞元土体模型，对土体力学特性颗粒尺度效应的物理机制进行解释。实验结果表明，随着土体中砂粒体分比增加和粒径的减小，土体的变形特性明显增强，其剪应力屈服强度也随之显著提高；砂粒的体分比对变形和强度颗粒尺度效应的影响比粒径的影响更为显著；胞元土体模型解释了实验结果的颗粒尺度效应的物理机制。
토체적물리역학특성수도과립척도급기급배적강렬영향，구유현저적과립척도효응。문중채용천연점토화상품석영사，제비구유불동과립립경화체분비적일계렬삼축항전시양，통과불고결불배수화고결불배수삼축항전시험，측득료응력응변관계곡선이급전응력굴복강도，기우시험결과대토체역학특성적과립척도효응진행분석；동시，인입포원토체모형，대토체역학특성과립척도효응적물리궤제진행해석。실험결과표명，수착토체중사립체분비증가화립경적감소，토체적변형특성명현증강，기전응력굴복강도야수지현저제고；사립적체분비대변형화강도과립척도효응적영향비립경적영향경위현저；포원토체모형해석료실험결과적과립척도효응적물리궤제。
The physical and mechanical characteristics of soil are obviously affected by scale and grade of grains,exhibiting remarkable grain size effect. By using the natural clay and commercial quartz sand,a se?ries of test samples with sand grains of different size and volume fraction are prepared, and curves of stress-strain and shear yield strength are obtained by unconsolidated-undrained and consolidated-undrained tri-axial shear tests. The analysis on the grain size effect of the soil mechanical characteristics is based on the test results, and the cell element model of soil is proposed to explain the physical mechanisms. The test results show that deformation properties and shear yield strength are improved remarkably with volume fraction increasing and particle size decreasing of sand in soil,and the volume fraction has a more obvious influence on grain size effect of deformation and strength characteristics than that of grain’s size. The cell element model of soil explains the physical mechanism of grain size effect of the tests results.