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    Survey the Change of Phreatic Line Position in the First Filling of Earth Dams until Steady State Seepage

    , M.Sc. Thesis Sharif University of Technology Razi, Arezoo (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Since seepage-related problems account for the cause of more than forty percent of dam failure seepage analysis serves as one of the most significant stage in the design process of an embankment dam. Currently a steady seepage analysis in a typical or maximum cross section of the dam is formed instead of transient seepage analysis for simplicity. In this way, for the change of condition (unsaturated to saturated) in the first filling of dams and it’s effects on behavior and reaction of dams until the steady seepage condition established; the results of steady seepage analysis cannot be satisfactory. In this thesis, based on finite element method and with assumption of saturated-unsaturated... 

    Numerical Study of Geotextile Application in Downstream Filter Zone of an Embankment Dam with Clay Core

    , M.Sc. Thesis Sharif University of Technology Maghsoodian, Maedeh (Author) ; Shamsaie, Abolfazl (Supervisor)
    Abstract
    Nowadays, applications of the synthetic materials are developing in civil engineering projects and widely used in these projects. Therefore, during previous years; use of the Geotextiles as one of the Geosynthetic materials in order to filtration, drainage, separation, soil protection, etc have developed ever-increasing. The goal of this research is modeling and studies of the Geotextiles application in the downstream filter zone of embankment dams in combination with granular materials using FLAC2D software. Gordeh Bin embankment dam situated in West Azerbaijan province has been chosen as case study. In this matter, different models have been made with changes in thickness of the inclined... 

    Settlement Evaluation of Earth Dams During Construction, First Impounding and Operation Periods by Monitoring Results and Numerical Modeling
    (Shahr chay & Zola dam; IRAN)

    , M.Sc. Thesis Sharif University of Technology Naghilo, Akbar (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Monitoring has a high level of importance in the predicting and controlling of dam behavior. At all large dams, the dam performance can be analyzed through the installation appropriate devices during dam construction, impounding and operation periods. The main purpose of monitoring and instrumenting is to investigate variations and safety of dam on the basis of long-term data observations. This paper is aimed at evaluating the behavior of earth dams from the aspect of deformation and settlement during dam construction, impounding and operation periods. As a case study, dams of Shahr chay & Zola, IRAN, have been studied. For this purpose, the obtained results from modeling, deformation and... 

    Flood Routing Studies, Dambreak Modeling – Case Study: Shahrchay Dam

    , M.Sc. Thesis Sharif University of Technology Heidari, Mohammad Reza (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Due to several reasons such as water deficiency and gradual reduce in water resources, dams had always been prominent during past centuries. Most of the dams have been built proximate to cities to provide water for drinking and industries thus, it’s vital to examine them in the aspects of safety factor and capacity to contain overflow. Failure of the dames should also studied considering different features such for instance sudden increment of stored water behind the dam as a result of gigantic floods, leakage in the body of soil dams, overflow in the dam crest due to insufficient functionality of spillway and etc. which could cause the failure of dams.
    The main purpose of this thesis... 

    Implementation of plasticity based models in dynamic analysis of earth and rockfill dams: A comparison of Pastor-Zienkiewicz and cap models

    , Article Computers and Geotechnics ; Volume 31, Issue 5 , 2004 , Pages 384-409 ; 0266352X (ISSN) Khoei, A. R ; Azami, A. R ; Haeri, S. M ; Sharif University of Technology
    Elsevier BV  2004
    Abstract
    In this paper, a unified finite element formulation associated with saturated and unsaturated soils is presented. The finite element method is applied to the governing equations for the spatial discretization, followed by a generalized Newmark scheme used for the time domain discretization. Time stepping scheme is used in the fully implicit coupled method and a direct solution procedure is used for the coupled equation system. The framework of generalized plasticity is presented and the numerical results of three saturated-unsaturated earth and rockfill dams are demonstrated. A comparison is performed between the Pastor-Zienkiewicz and cap plasticity models through the dynamic analysis of... 

    Evaluation of the Behaviorof Earth and Rockfill Dams during Construction and First Impounding using Instrumentation data and Numerical Modeling (Case Study: Dam Gavoshan)

    , M.Sc. Thesis Sharif University of Technology Rashidi, Mohammad (Author) ; Haeri, Mohsen (Supervisor)
    Abstract
    Monitoring is of particular importance after impounding and during dam operation. In all large dams, by installation of the required instruments the pore pressure, soil mass pressure and displacement during construction, first impounding and operation are measured, then the performance of dam will be analyzed and evaluated. The aim of this study is to evaluate the performance of the "Gavoshan" dam, which has an important role on agriculture development and drinking water supply at west part of Country. To reach this, the values resulting from instruments have been implemented by FLAC software, using "Back Analysis" method. However, this assessment is complete when "back analysis" method is... 

    Verification of Two and Three Dimensional Seepage Analyses Results’ Correctness in Embankment Dams According to Instrumenting Data (Case Study: ZAGROS, SHIAN & HAALEH Dams)

    , M.Sc. Thesis Sharif University of Technology Yarahmadi, Nazanin (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Since, seepage- related problems account for more than forty percents of earth dams’ failure, seepage analysis is one of the most important stages in designing of embankment dams. The most usual method of making a seepage analysis is doing a two dimensional one in the maximum cross- section and generalizing its results to the third dimension. As a natural consequence of this kind of seepage analysis, the effect of valley shape and material properties’ changes along the third dimension are ignored and so, in narrow valleys where the cross-section changes along longitude profile or in the specific cases of nonhomogeneity, using this kind of analysis can make false results. Besides, because of... 

    Experimental Study of the Mechanical Behavior of Plastic Concrete Cutoff Walls

    , M.Sc. Thesis Sharif University of Technology Mousavi, Hamed (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    The seepage through foundation of earth dams causes the serious menaces and the reduction in their efficiency. Therefore essential contrivances must be provided against mentioned problem. One of the common and efficient ways to control the seepage through pervious layers under earth dams is plastic concrete cut off wall which is used as a filling material in dam foundation due to the low permeability, plastic behavior and low enough elastic modulus compatible with the adjusted soil. In addition to the mentioned properties, it is important that plastic concrete have an adequate compressive strength to sustain the lateral and vertical loads. Since the change in the ratio W/C (water to cement)... 

    Developing an Object-oriented Computer Program for Seepage Analysis through Earth Dams using Boundary Element Method

    , M.Sc. Thesis Sharif University of Technology Asadi, Roza (Author) ; Ashtiani, Ataie (Supervisor)
    Abstract
    Destruction of a dam is not only an economic disaster but also a catastrophe for the down stream residents. Seepage related problems are the main reasons for the destruction of the embankment dams. Therefore controlling seepage in an earth dam is of great importance.Graphical, experimental,and numerical methods can be applied for analysis of seepage problems in embankment dams.Due to the complexity of geometry and of in homogeneous and/or anisotropic media there are few analytical solutions to porous media problems. Numerical solutions have long played an important role in ground water calculation such as Finite Difference Method (FDM),Finite Element Method (FEM) and Boundary Element Method... 

    Piping Dam Breach Physical and Numerical Modelling Evaluation

    , M.Sc. Thesis Sharif University of Technology Seyed Raoufi, Arian (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    In past few centuries , dams have been always a crucial part of human life . Using dams for agriculture and supplying water for people , has made them a valuable asset for countries . So evaluating dam safety and dam breach properties is so important. This issue is a geotechnical , structural and hydrological matter. Safety of earth dams could be threatened due to dam body breach caused by overtopping or pipping, during heavy floods, strong ground motions or any structural damage or defection. As in previous studies , calculating the final geometrical breach properties and time of failure was the main goal , we tried to connect this characteristics and find the relation of time and breach... 

    Extended finite element modeling of deformable porous media with arbitrary interfaces

    , Article Applied Mathematical Modelling ; Volume 35, Issue 11 , 2011 , Pages 5426-5441 ; 0307904X (ISSN) Khoei, A. R ; Haghighat, E ; Sharif University of Technology
    Abstract
    In this paper, an enriched finite element method is presented for numerical simulation of saturated porous media. The arbitrary discontinuities, such as material interfaces, are encountered via the extended finite element method (X-FEM) by enhancing the standard FEM displacements. The X-FEM technique is applied to the governing equations of porous media for the spatial discretization, followed by a generalized Newmark scheme used for the time domain discretization. In X-FEM, the material interfaces are represented independently of element boundaries and the process is accomplished by partitioning the domain with some triangular sub-elements whose Gauss points are used for integration of the... 

    Numerical analysis and monitoring of an embankment dam during construction and first impounding case study: siah sang dam

    , Article Scientia Iranica ; Volume 25, Issue 2A , 2018 , Pages 505-516 ; 10263098 (ISSN) Rashidi, M ; Heidari, M ; Azizyan, Gh ; Sharif University of Technology
    Sharif University of Technology  2018
    Abstract
    Monitoring embankment dams is of crucial importance. In earth dams, the pore pressures, earth pressures, and displacements occurring during construction and function are measured at the time of the first impounding and exploitation by installing essential instruments, and so the dam's performance is evaluated and analyzed. Scope of the present research is the evaluation of Siah-Sang Dam performance through the results of instruments and back analysis, conducted by FLAC software. The Mohr-Coulomb elasticplastic model has been considered as the behavioral model of the dam, and the effect of the upstream shell's materials deformation has been modeled at the time of the initial impounding.... 

    Strength parameters of asphalt concrete used in core zone of earth dams

    , Article Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering ; Volume 2 , 2009 , Pages 1558-1561 ; 9781607500315 (ISBN) Jafarzadeh, F ; Yousefpour, N ; Sharif University of Technology
    Abstract
    Strength parameters of asphalt concrete used in earth fill dams' core were studied by conducting cyclic and monotonic triaxial tests on asphalt concrete samples. Results obtained from more than 120 cyclic tests showed that asphalt concrete behaves properly under cyclic loading and specimens stay intact after applying 5000 cycles. Results of monotonic and post-cyclic loading proved that strength parameters of asphalt concrete samples does not change significantly after being subjected to seismic loads. © 2009 IOS Press  

    Nonlinear Dynamic Analysis of Earth and Rockfill Dams Using the Finite Difference Method Considering the Effect of Vertical Earthquake Component

    , M.Sc. Thesis Sharif University of Technology Babaee, Mohammad Saeed (Author) ; Haeri, Mohsen (Supervisor)
    Abstract
    Earth and rockfill dams are enormous three-dimensional structures constructed from earth and rockfill materials. They are mainly built for water supply, agricultural land irrigation, electricity generation, and flood control. Earthquake is one of the most significant natural hazards affecting the stability of these dams. Nowadays, with the development of computers and software, the seismic behavior of most dams are assessed by dynamic analysis. In a considerable part of technical literature, dynamic analysis of earth and rockfill dams have been performed by applying only the horizontal component of the earthquakes, and the effects of vertical component of the earthquakes have often been... 

    Seismic Analysis of Cemented Material Dam(CMD)on Weak Foundation

    , M.Sc. Thesis Sharif University of Technology Feizollahzadeh, Mohammad (Author) ; Ghaemian, Mohsen (Supervisor)
    Abstract
    Cemented material dam(CMD) are a type of dams constructed using cement-based materials. They are situated between earth dams and roller-compacted concrete (RCC) dams and are used in irrigation and hydropower projects. These dams are known for their high strength and stability and can be easily built on various foundations, including weak foundations. One of the significant advantages of cemented material dams is their reduced environmental impact, leading to less damage to surrounding lands and improved environmental sustainability. Considering the mentioned advantages and appropriate locations and foundations for dam construction are used, building cementitious material dams on soft... 

    Numerical modeling of multiphase fluid flow in deforming porous media: A comparison between two- and three-phase models for seismic analysis of earth and rockfill dams

    , Article Computers and Geotechnics ; Volume 38, Issue 2 , March , 2011 , Pages 142-166 ; 0266352X (ISSN) Khoei, A. R ; Mohammadnejad, T ; Sharif University of Technology
    Abstract
    In this paper, a fully coupled numerical model is presented for the finite element analysis of the deforming porous medium interacting with the flow of two immiscible compressible wetting and non-wetting pore fluids. The governing equations involving coupled fluid flow and deformation processes in unsaturated soils are derived within the framework of the generalized Biot theory. The displacements of the solid phase, the pressure of the wetting phase and the capillary pressure are taken as the primary unknowns of the present formulation. The other variables are incorporated into the model using the experimentally determined functions that define the relationship between the hydraulic...