Sharif Digital Repository

The Latian dam is located on the Jajrood River in the northeast of Tehran the capital of Iran. It is one of the most important water supply reservoirs in this city and supplies 30 percent of the total water demand of 11 million people in this city. This research measures phosphorus release from sediments of Latian Dam and the role of the tubifex in phosphorus release. Because of sediment composition variation, sediment sample were taken from two points in the Latian dam. The sediments were analyzed for total phosphorus, the form of phosphorus and release rate under different conditions of water column and the absence or present of tubifex. The results show that the amount of phosphorus are... 

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... 

A three-dimensional finite element analysis was carried out to determine the annual variation of temperature and thermal stresses of a concrete arch dam. Appropriate heat transfer boundary conditions in the dam body were used for air and reservoir temperature as well as solar radiation variations. Karaj arch dam in Iran was used as a case study. The rate of convergence of the numerical solution is examined. Results of the finite element analysis show that probable cracks occur in a very narrow region of the downstream face. Thermal loads have the most significant effects for causing downstream cracks in comparison with self-weigh and hydrostatic loads. The cracked areas of downstream face... 

Thermal analysis of Roller Compacted Concrete (RCC) dams is generally carried out considering identical ambient boundary conditions at upstream and downstream faces. For the case of Shahri-Kor Dam (an RCC dam with a height of 57 m), recorded thermal data depicts a considerable difference between upstream and downstream ambient temperatures, especially during cold months. This paper investigates how taking this difference into account can affect the thermal response of the dam. For this purpose, two thermal analyses are carried out with and without consideration of these different ambient boundary conditions (DABC). Consequently, the computed temperatures at representative points are compared... 

Mine tailings are the most common materials that are used in construction of tailings dams. Due to high level of environmental hazard and serious consequences that are associated with tailings dam failure, proper design of tailings dams is an important factor in mining industry. Water level fluctuation, change in permeability of dam foundation, seismic loads, and excessive settlements are the most common reasons of failure, particularly in upstream type tailings dams. Due to low shear strength of wet tailings, drying of tailing material is very common in practice during the dam construction. In hot climate, the received solar energy at the soil surface converts to soil heat flux, air heat... 

A rectangular labyrinth weir has a very good flood release capacity as well as strong economical and structural advantages. In this study, combined analytical and experimental investigations were undertaken for a rectangular labyrinth weir. The analytical model is based on the synthesis of general weir equations and spatially varied flow dynamic equations. A comprehensive set of experiments led to characterisation of the flow behaviour for low and high heads over the weir and indicated the influences of weir geometry on the release capacity. The results show that this type of weir represents an effective weir alternative and could be five times more efficient than a corresponding traditional... 

Coupling the adjacent zones for seepage analysis in porous media needs compatibility and equilibrium equations (equality of potential on coinciding nodes and conservation of flowing mass between zones, respectively). When stretched coordinate transformation is applied to the anisotropic zones, the Dirichlet boundary conditions remain unchanged, but the Neumann boundary condition should also be transformed. Similarly in a zoned problem, for the interface between zones, compatibility equations remain unchanged during the transformation while the equilibrium equations should be transformed. In this paper, transformed Neumann boundary conditions and equilibrium equations for the interface of... 

Recently, for zero ordering cost a new ordering policy named (1, T), in which the time interval between two consecutive orders and the value of the order size are both constant, have been developed for nonperishable products. In this paper, the (1, T) policy is developed for perishable products. Using an analogy among this inventory model, a queueing model with impatient customers, and a finite dam model, the long-run average total cost function of the inventory system is derived. It is observed that the total cost rate is independent from the lead time as is for nonperishable products. Since analyzing the convexity of the model is extremely complicated, a proposition is proved to define a... 

Seismic performance and safety of a jointed arch dam, as an arch-shaped mass concrete structure, are investigated through the nonlinear incremental dynamic analysis. In this way, 12 proper ground motions are selected, each of them is scaled to 12 successively increasing intensity levels and applied to the dam. Three and seven contraction joints are inserted within the dam body, and stage construction is taken into account. Several main assumptions including dam–reservoir–foundation dynamic interaction, absorbing boundary conditions at the far-ends of the reservoir and foundation, and material and joint nonlinearities are considered. The failure modes of the dam are determined according to... 

This paper represents a numerical study on the effects of landslide initial submergence and its geotechnical and rheological properties on the characteristics of landslide-generated waves (LGWs) and landslide deformation. A number of 117 numerical experiments are performed using a two-layer Coulomb Mixture Flow (2LCMFlow) model on a real-sized numerical flume as a simplified cross section of the Maku dam reservoir, located in the Northwest of Iran. Three different initial locations are considered for landslide representing a subaerial (SAL), a semi-submerged (SSL), and a submarine (SML) landslide. Based on the numerical results, the majority of SMLs and in some cases SSLs generate tsunami... 

The effect of Alkali-Aggregate Reactions (AAR) in concrete dams was investigated using the finite element method. Two models have been presented to assess the effects of the AAR in concrete dams. The stress dependency of AAR strains has been taken into account in the models and the degradation of concrete properties during the reaction has been implemented in the finite element program. The results of the isothermal and nonisothermal analyses of a gravity section of a Beauharnois power plant have been presented and compared with the measured data and the results are in close agreement. The results of the analysis demonstrate the importance of the AAR in concrete dams. High stresses and large...