A Micro-structural Study on Hydro-mechanical Behavior of Loess

, Ph.D. Dissertation Sharif University of Technology Sadeghi, Hamed (Author) ; Jafarzadeh, Fardin (Supervisor) ; W. W. NG, Charles (Supervisor)

Abstract

Loess soil layers in semi-arid to arid areas have been deposited through the accumulation of aeolian sediments, resulted in a special metastable and open structure being usually unsaturated in nature. Since naturally occurred loess is widespread, it has been recently considered as a promising resource for constructing earth-fill structures. However, due to different microstructures of intact and recompacted loess, different responses to hydraulic and mechanical loading would be expected. Up to now, the hydro-mechanical behavior of loess from different perspectives has not been linked to its microstructural characteristics. The current research, therefore, aims to provide insight into the...

Investigation of Stress-Dependence on Hydro-Mechanical Properties of Fractured Rocks

, M.Sc. Thesis Sharif University of Technology Khazaie, Sina (Author) ; Goodarznia, Iraj (Supervisor)

Abstract

Fracture and Matrix permeability systematically change because production time of gas and oil reservoirs is very long and pore pressure, temperature and in-situ stresses continously change in reservoirs.This parameters have an important role in determination and development of wells according to the permeability distribution.The main factors in determination of fracture permeability values is normal and shear stiffness that parameters such as roughness, opening, closure, aperture and asperities influence this factor.In this thesis, we try to investigate the influence of this parameters on fracture permeability according to the normal and shear stresses.Also we want to investigate the...

Expansion Modeling of Coronary Stent for Selection of Optimized Stent

, M.Sc. Thesis Sharif University of Technology Izadi Ramini, Elaheh (Author) ; Movahhedy, Mohammad Reza (Supervisor)

Abstract

Referring to mortality increasment having sprung from atherosclerosis, work on treatment of coronary heart disease seems to be necessary. Stent implementation is one of stenosis treatment. Stent deployment has been done during past two decades, but clinical evidence showed that because of some weakness in designing and implementing, restenosis occurs again. Material, structure and coating texture of stent are the designing criteria beside stent implementation importance. Thus a lot of activities have been done in this area to improve performance of these applications. Nowadays a lot of companies' researchers try the best to get better their products; consequently there is different types of...

Experimental Study on the Effects of Initial Suction and Particle Shape on Consolidation and Shear Behavior of Unsaturated Sandy Soils

, M.Sc. Thesis Sharif University of Technology Mousavi Avindin, Zahra Alsadat (Author) ; Jafarzadeh, Fardin (Supervisor)

Abstract

Particle morphology refers to the dimensions, shape, surface texture, roundness, and form of the particles. Morphology has a direct impact on the interaction between soil particles. Friction, particle rearrangement, dilation, and interlocking are influenced by the shape and size of the particles. The extensive impact of morphology on soil properties and behavior necessitates a comprehensive examination by geotechnical engineers to predict the behavior of granular materials accurately. Morphology significantly affects soil behavior under shear, volumetric changes, dilative behavior, shear strength, and soil behavior during consolidation testing, as well as changes in void ratio and...