水力发电学报2025，Vol.44Issue(1)：54-63,10.DOI:10.11660/slfdxb.20250105
三轴加载条件下粗粒土剪切带的细观演化规律
Meso-evolution of shear bands of coarse-grained soil under triaxial loading
摘要
Abstract
Coarse-grained soil is widely used for the fill construction of rockfill dams and exhibits macroscopic mechanical properties affected by particle movement and mesoscopic deformation.In this study,Computed Tomography(CT)triaxial tests are conducted on coarse-grained soil of weathered phyllite,combined with digital image processing techniques,to quantitatively analyze its particle movement,local deformation and failure processes under controlled loading conditions(i.e.loading rates),focusing on the macro-and micro-structural characteristics.The results indicate that Unsharp Masking(USM)sharpening and material segmentation,when used to enhance CT images,will effectively highlight the boundary characteristics of soil particles.Significant deformation differences can be observed in various regions within a specimen.Near the two ends of the specimen,deformation takes a major form of relatively uniform axial compression,while near a failure surface,it manifests as compression and lateral spreading.In shear zones,the average CT number increases first and then decreases as an evident trend,indicating strain distribution is reflected by particle movement and local deformation.For a specimen with higher confine pressure,its shear bands show a coupling of tangential dislocation and normal dilation,developing progressively along the shear surface.At an axial strain around 16%,local regions accelerate to failure.Generally,shear band formation involves the stages of compaction,initiation,expansion,and penetration.关键词
粗粒土/三轴试验/CT试验/图像处理/剪切带/破坏Key words
coarse-grained soil/triaxial test/CT test/image processing/shear band/failure分类
建筑与水利引用本文复制引用
万航,周跃峰,邓茂林,左永振,赵艺颖,王磊..三轴加载条件下粗粒土剪切带的细观演化规律[J].水力发电学报,2025,44(1):54-63,10.基金项目
国家自然科学基金资助项目(51979010 （）
42172303) （）
中央公益性科研院所基本科研业务费项目(CKSF2023318/YT) （CKSF2023318/YT）
