Sharif Digital Repository

The interface behavior of rock-concrete joints and between concrete layers influence the behavior of concrete dam structures. In this study, a modified direct shear test (DST) was implemented in the laboratory to evaluate the interface behavior between 1) rock and conventional vibrated concrete (CVC), 2) rock and roller compacted concrete (RCC), 3) CVC and RCC and 4) two layers of RCC. Two series of in-situ shear tests were also carried out on rock-concrete joints. The friction angle and adhesion for all tested interfaces were determined and analyzed. The effect of uniaxial compressive strength (UCS) of concrete on the interface behavior was determined. Additionally, the effect of surface... 

Damming projects always have been important while construction, operation and even demolition due to their major effects on society, environment and economy. Although researchers have focused on one or a few phases of construction projects to develop sustainable infrastructures, the research community has to consider long term effects of developments too. There are a variety of such effects that ignoring them will cause construction of not convenient infrastructures i.e. air pollution and over-consumption of energy resources while construction, operation and demolition. Therefore, it is suggested to consider life cycle assessments to include all bad effects in all phases of a project. Dams... 

The economic effects of large dams that were constructed during 1370-1393 in Iran are explored in this thesis and their effects on agriculture and welfare of their own district and downstream districts are analyzed. Ordinary Least Squares (OLS) method is used to investigate these effects and for more accurate results, we control for geographical variables and rainfall. The results of this study show that dam construction leads to higher agricultural yield, production value and irrigated area in the dam’s own district; but it doesn’t affect yield, production and irrigated area of downstream districts. Also dam construction results in planting more water-intensive crops in their own district... 

In recent years, machine learning techniques have been available to predict and interpret the structural behavior of dams. The main goal of this research is to predict structural behavior through modeling with data read by accurate instruments of dams. This requires the selection of several machine learning methods such as Random Forests (RF), Boosted Regression Trees (BRT), Artificial Neural Networks (ANN), Support Vector Regression (SVR), and Decision Tree Regression (DTR) algorithms. In this research, considering the 24 target variables defined from the detailed instrumentations studied, the behavior of the dam is modeled using selected machine learning models. These precision instruments... 

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... 

In this research, a new method is proposed for constructing concrete structures with complex geometry, including topology-optimized concrete dams on a small scale. According to global statistics, concrete is the most consumed material in the world after water, and its production process causes a lot of damage to the environment. One of the best ways to reduce concrete consumption is to use tools such as topology optimization to design concrete structures. Nevertheless, few research has been done in the field of topology optimization of concrete dams, one of the important reasons for which is the difficulty of building physical model to perform physical tests, validating numerical models, and... 

Karun 4 arch concrete dam with a height of 230 meters is designed and built in one of the most complex natural places. Therefore, monitoring the behavior and evaluating the safety and stability of this dam, both with regard to the height and nature of the dam itself and with regard to its national and international dimensions, is of special importance and sensitivity. This sensitivity is doubled due to some problems and issues encountered in the body of the Karun 4 dam, which of course are considered probable and possible phenomena in arch concrete dams. The Karun 4 Dam construction site is located in the southwest of Iran on the Karun River, immediately upstream of the Karun 3 Dam reservoir... 

The instability and contamination leakage through tailings dams is one of the major problems of them. These dams are usually constructed through self-consolidation with minimum compaction effort, so special attention must be given to the stability of these structures. In addition, tailings dams contain considerable amounts of metals and chemically soluble contaminants resulting from mining processes in their reservoirs, making them more likely to leak contamination from the dam's foundation and body, causing pollution downstream. The infiltration of various chemical contaminants into the soil may alter its hydraulic and resistance properties. Laboratory studies have shown that pore solution... 

The purpose of this research is to first provide an algorithm to reduce the scale of large-scale microwave soil moisture images and then develop an algorithm based on it to manage the release of dams downstream of which are agricultural lands and wetlands. Considering that providing irrigation needs is the purpose of building dams and agriculture is the main consumer of water in dams, optimizing the related releases has a significant effect on reducing water consumption and the possibility of releasing more water for water needs. It has a downstream environment, also agricultural water management has a direct impact on the production of agricultural products and preservation of natural... 

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... 

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... 

Shahid Kazemi reservoir is the largest, and the most strategic dam of Urmia Lake basin is located on the Zarrineh Rood River in the south of this basin. This reservoir is responsible for supplying drinking water to large cities such as Tabriz, the agricultural demands of significant plains, including the Miandoab plain, and most importantly, the environmental demands of Urmia Lake and downstream rivers. In recent years, due to increased consumption upstream of the dam and agricultural development downstream of the, Urmia Lake has faced water shortages. This study develops the first daily runoff forecast system for Shahid Kazemi reservoir in Urmia Lake basin (ULB), Iran, an important region... 

Nowadays, due to advancements in technology and processing power, earthquake engineering is moving toward more realistic modeling of actual problems in different fronts. In the case of considering seismic waves for design and analysis of concrete dams, numerous challenges exists due to complex nature of the problem which have absorbed abundant attention from a number of researchers around the world. In recent studies about earthquake input mechanisms, accounting for true nature of the foundation and applied earthquake have been hot topics. Therefore, in this thesis, thorough investigation on these effective factors in dynamic analysis of concrete dams is performed.In the first part of this... 

Roller compacted concrete is a dry concrete with zero slump which is constructed in layers. Roller compacted concrete dams are generally weak in interlayers. The bonding strength and permeability of the interlayer affect the performance of the dam’s structure and its safety. In this study, the mechanical characteristics and the permeability of the interface layer of RCC are investigated by considering three key parameters, including water-to-cement ratio (w/c) of concrete, w/c ratio of bedding mortar and time interval between pouring each layer. More than 300 RCC specimens are prepared. To evaluate the properties of the interface between the mortar and the first layer surface, various tests... 

The amount of water entering the dam is one of the types of information that has a direct impact on how to plan the discharge and storage of the dam's water supply. Given the precise input streamflow predictions of the next few days, the corresponding authorities can better manage the amount of water that should remain in the storage in the days to come. In this regard, it is no longer necessary to release huge amounts of stored water due to the lack of information on the volume of water entering. Consequently, the volume of water stored in the reservoir, increases. Also, the probability of occurrence of potential hazards such as dam overflow is prevented.Over the last few years, due to the... 

The Droughts in various parts of the world cause a lot of economic and social damage every year. In fact, droughts are due to climate fluctuations that are inherent in the natural processes of meteorological and hydrological processes and reduce water resources; population growth; Of course population growth, exacerbates its consequences. Research as well as observations have shown that climate change also exacerbates extreme phenomena such as drought and flood. The population of Kabul city, the capital of Afghanistan, is increasing due to migration from other cities, and on the other hand, the flow of the river in the summer is minimized, which for some years leads to drought. In these... 

A finite element model for seismic analysis of concrete arch dams is proposed. Material inelasticity as well as joints nonlinearity is considered. In order to provide a precise description of concrete response, a novel plastic-damage constitutive model for plain concrete is developed. For this purpose, the microplane theory is proposed for overcoming the deficiency of available anisotropic continuum plastic-damage models in reproducing the true anisotropic nature of damage in multidimensional loadings.Based on the microplane theory, the degeneration process in concrete is considered along with plastic deformations. Using the principle of strain energy equivalence, a transformation between... 

Rockfill dams are a kind of gravity dams that a major part of the dam’s body is made of rock particles. The specific feature of these dams is the high settlement of rockfill layers so, numerical simulation of the behavior of these dams for predicting their settlement is of prime importance. However, the normal procedure of numerical modeling and the analysis of stresses and deformations using common engineering softwares usually does not work because the behavior of rockfills is not well understood. Evaluating the mechanical behavior of rockfill layers is not usually possible in the laboratory because of the large dimensions of these particles which are sometimes larger than one meter.... 

Despite there are many publications and press on the benefits and costs of dams from a purely single-discipline perspective, but recent studies simultaneously assess biophysical, economic, and social issues as well as concepts related to political geography about dams. The purpose of this study is to model the benefits and costs of constructing a dam from a multi-field perspective. The Integrative Dam Assessment Modeling (IDAM) is designed to integrate biophysical, economic, social and political geography perspectives into a single cost-benefit analysis of dam construction. In particular, a new tool of integrative dam assessment model has been proposed to evaluate the costs and benefits... 

Mount Polley Tailings Storage Facility (MP-TSF) failed on its perimeter embankment on August 4, 2014, when its 9th construction stage has just been completed. The failure releasedmillions of m3 of toxic tailings, supernatant water and construction materials todownstream. Up to this point, some research studies have been conducted into the causes of the failure. These studies have considered the stability of the TSF in different stages of its construction as well as in the last stage. The aim of the present study is to investigate the causes of the very failure, using numerical methods by the aid of the finite element based software, PLAXIS 2D. In the present study, the results of the...