This paper aims at establishing an anisotropic stress expression for unsaturated pendular-state granular soils. Using the second-order fabric tensor, we formulate a micromechanics scheme of soils with statistically av...This paper aims at establishing an anisotropic stress expression for unsaturated pendular-state granular soils. Using the second-order fabric tensor, we formulate a micromechanics scheme of soils with statistically averaging method, and reveal that the macroscopic average stress of unsaturated granular soils in pendular-state is not isotropic. Not only is the stress from contact forces anisotropic due to the fabric, but also the capillary stress is directional dependent, which is different from the common point that the capillary stress is isotropic. The capillary stress of unsaturated pendular-state granular soils is determined by the orientation distribution of con- tact normals, so it is closely related to the initial and induced anisotropy of soils. Finally, DEM numerical simulations of triaxial compression tests of pendular-state soils at different degrees of saturation are used to verify the existence of above anisotropy of stresses.展开更多
The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling plants.In this study,an experimental system was designe...The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling plants.In this study,an experimental system was designed to investigate the adhesive tensile contact between a range of iron ore materials and wall lining specimens.The contact mechanism between the material specimen and the wall surface was initially characterised.The experimental results indicated that the adhesive tensile stress is dependent on both the moisture content and the applied major consolidation stress,with the former exhibiting more significant contribution to increasing the magnitude of stress.The surface roughness of the wall showed a negligible effect in determining the adhesive tensile stress.Additionally,the iron ore sample with a higher fines content was observed to be able to achieve a higher adhesive tensile stress compared to the coarse samples.Consequently,the insights resulting from the study demonstrated practical applicability through measures such as blending and/or beneficiation,which reduce the adhesive tensile stress and minimise blockages.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 50778013)the National Basic Research Program (973) of China (No. 2010CB732100)
文摘This paper aims at establishing an anisotropic stress expression for unsaturated pendular-state granular soils. Using the second-order fabric tensor, we formulate a micromechanics scheme of soils with statistically averaging method, and reveal that the macroscopic average stress of unsaturated granular soils in pendular-state is not isotropic. Not only is the stress from contact forces anisotropic due to the fabric, but also the capillary stress is directional dependent, which is different from the common point that the capillary stress is isotropic. The capillary stress of unsaturated pendular-state granular soils is determined by the orientation distribution of con- tact normals, so it is closely related to the initial and induced anisotropy of soils. Finally, DEM numerical simulations of triaxial compression tests of pendular-state soils at different degrees of saturation are used to verify the existence of above anisotropy of stresses.
文摘The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling plants.In this study,an experimental system was designed to investigate the adhesive tensile contact between a range of iron ore materials and wall lining specimens.The contact mechanism between the material specimen and the wall surface was initially characterised.The experimental results indicated that the adhesive tensile stress is dependent on both the moisture content and the applied major consolidation stress,with the former exhibiting more significant contribution to increasing the magnitude of stress.The surface roughness of the wall showed a negligible effect in determining the adhesive tensile stress.Additionally,the iron ore sample with a higher fines content was observed to be able to achieve a higher adhesive tensile stress compared to the coarse samples.Consequently,the insights resulting from the study demonstrated practical applicability through measures such as blending and/or beneficiation,which reduce the adhesive tensile stress and minimise blockages.
