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Effect of Major Principal Stress Direction Rotation on Cyclic Behavior of Dense Sand Using Dynamic Hollow Cylinder Aparratus
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
In the past years a lot of research has been done on effects of different parameters on dynamic behavior of soils. According to these studies, principal stress direction rotation and intermediate principal stress coefficient have a major effect on monotonic behavior of soils, but more studies needed for observingtheir effect on dynamic behavior of soils.
In recent study undrained isotropic consolidated specimens of dense Babolsar sand subjected to α changes using dynamic hollow cylinder apparatus and the inner and outer cell pressure kept constant so that b was relative to α changes.
Fisrt series of testswere done to find an appropriate value for induced cyclic deviator stress. The...
In recent study undrained isotropic consolidated specimens of dense Babolsar sand subjected to α changes using dynamic hollow cylinder apparatus and the inner and outer cell pressure kept constant so that b was relative to α changes.
Fisrt series of testswere done to find an appropriate value for induced cyclic deviator stress. The...
Damage evolution in Saffil alumina short-fibre reinforced aluminium during tensile testing
, Article Materials Science and Engineering A ; Volume 395, Issue 1-2 , 2005 , Pages 27-34 ; 09215093 (ISSN) ; Weber, L ; Mortensen, A ; Sharif University of Technology
2005
Abstract
The evolution of microstructural damage during tensile deformation of pure aluminium reinforced with 10 vol.% alumina short fibres is studied by monitoring the evolution of density and Young's modulus as a function of tensile strain. It is found that Young's modulus drops rapidly until a strain εc ≈ 3%. The composite density remains virtually unchanged in this strain range. At strains above εc, Young's modulus decreases more slowly while the density begins to decrease linearly, indicating void growth in the composite. It is shown that the drop in Young's modulus is linked to fragmentation of fibres aligned along the stress axis, while the decrease in density is related to void opening across...
Evaluation of the Effect of Anisotropy on Cyclic Behavior of Sands with Hollow Cylinder Apparatus
, Ph.D. Dissertation Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
Direction of loading and magnitude of the intermediate principal stress have significant effect on the soil responses. In many of in-situ loading the direction of major principal stress is not coincide to the deposition direction of the soil. Also, the magnitude of the intermediate principal stress should be exerted in the three dimensional loading condition. A reliable assessment of the soil behavior and a good estimation of the soil parameters need to do tests in similar condition with in-situ. So the testing apparatus should be able to control the loading direction in various stress paths. Typical equipments used in the geotechnical laboratory have not the ability to control the magnitude...
Evaluation of the Effects of Principal Stress Direction on Dynamic Properties of Unsaturated Sand by Hollow Cylinder Apparatus
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
Soils have an anisotropic response, and mechanical and dynamic properties of this material are greatly dependent on the direction and magnitude of principal stresses. A reliable assessment of the soil behavior and a good estimation of the soil parameters need to perform tests in similar condition with in-situ. From all the devices used for studying anisotropy of soils, hollow cylinder apparatus is the only apparatus that enables an independent control of both the direction and magnitude of the principal stresses. Moreover, one of the most controversial topics in the unsaturated soil dynamics is determining the shear modulus and damping ratio which are used for assessing many geotechnical...
Effect of Principal Stresses Direction, Anisotropic Consolidation and Silt Content on the Behavior of Silty Sands by using Hollow Cylinder Apparatus
, Ph.D. Dissertation Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
In this research, the effect of various parameters on the behavior of silty sands is evaluated under special loading conditions. To evaluate these parameters, the hollow cylinder apparatus of the Advanced soil mechanics at Sharif University is used. In this research the effect of principal stress directions, initial anisotropic consolidation, silt content, effective mean normal consolidation stress and intermediate principal stress are studied on the behavior of silty sands including the strength and pore water pressure. In order to evaluate these parameters, the specimens are made with wet tamping method with 0, 10, 20, 30 and 40 percent of silt. Before applying shear load to specimen, the...
Development of Hollow Cylinder Apparatus for Testing of Unsaturated Sandy Soils
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
The main purpose of this study is to develop the Hollow Cylinder Apparatus (HCA) for unsaturated testing on granular materials and to investigate the effect of stress anisotropy on dynamic parameters of soils like shear modulus and damping ratio. Direction of loading and the magnitude of intermediate principal stress have significant effect on the anisotropic response of soils. In many of in-situ loading the direction of major principal stress does not coincide with deposition direction of soil or because of the three dimensional loading condition of soil, the effect of the intermediate principal stress cannot be ignored. On the other hand, in many areas, soils are in unsaturated condition....
The Effect of Induced Anisotropy on the Dynamic Properties of Unsaturated Sand at Constant Suction by Hollow Cylinder Apparatus
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
Soils have an anisotropic response, and mechanical and dynamic properties of this material are greatly dependent on the direction and magnitude of principal stresses. A reliable assessment of the soil behavior and a good estimation of the soil parameters need to perform tests in similar condition with in-situ. From all the devices used for studying anisotropy of soils, hollow cylinder apparatus is the only apparatus that enables an independent control of both the direction and magnitude of the principal stresses. Moreover, one of the most controversial topics in the unsaturated soil dynamics is determining the shear modulus and damping ratio which are used for assessing many geotechnical...