نشریه سد و نیروگاه برق آبی ایران
پیاپی 24 (بهار 1399)

This research was aimed at evaluating and promoting the HSE culture in the Shirvan combined cycle power plant. 125 people were selected as the statistical population and the hypotheses were tested. Based on the results of the IFE 663/2 matrix and the EFE 875/2 matrix, there is evidence of overcoming strengths over weaknesses and opportunities for threats. The aggressive strategy was declared as an appropriate strategy and, toward  the results of the QSPM matrix, the awareness-raising scenario for staffing (by providing brochures, slides, banners and training classes) with a score of 33.33 as the best solution Introduced

The scouring process at downstream of the hydraulic structures is a complex phenomenon and many parameters affecting its amount. Failure to control this phenomenon causes damages to the dam and its associated hydraulic structures. In this research, the scouring caused by the combination of jets outlet from a gated spillway was investigated experimentally and the combination of jets adjacent to each other or with a distance from each other inside the plunge pool was studied. For this purpose, 25 experiments have been carried out on the experimental model and the effect of important parameters such as flow rate or discharge, densiometric Froud number, depth of tail water and how jets are combined.The results show that in a same discharge, combined of two non-adjacent spillway jets has lower scour depth and sediment height, and the length of the scouring than the jet of a combination of two adjacent jets. The width of the scouring pit, however, is in the case of overflow jets in non-adjacent jets more than adjacent jets.

One of the most important effective parameters in design of engineering structures is deformability of rock mass. Benchmark of rock mass deformability is the deformation modulus that directly or indirectly obtained. Since the determination of rock mass deformation modulus indirect method by in-situ tests is time-consuming, costly and difficult from executive operations aspect, so it’s correctly estimation indirectly is important. In this project, in addition to the describing of rock mass of Ruodbar Lorestan pumped storage cavern with the rock mass index (RMi), the dilatometer tests in exploratory gallery around the storage cavern is simulated with numerical method. In the Roudbar storage cavern addition to bedding, three joint sets along with the fault areas in rock mass are observed. Therefore, assuming of the equivalent continuum environment from the finite difference method (FLAC 3Dsoftware) is used for numerical modeling of the dilatometer test. The deformation modulus also has been estimated by RMi experimental method. Investigations are indicative about 51 percent difference between experimental method and in-situ test results.

If the parties can have the quantity of all the direct and indirect extra costs _caused by the delays_ they may gain a better perspective to have more reliable time management plan and prevent the probable future financial damages. The goal of this research is to figure out the negative effects of delays, both direct and indirect aspects. After determining these aspects and their effects, by considering the contract type and project delivery system, delays can be analyzed by the method of daily windows and under multiple baseline updates. Hence, the financial damages, which are the outputs of this model, can be allocated to the different parties (e.g. client and contractor). On the other hand, this model can calculate the damages based on the comparison of scheduled and hypothetic scenario. According to this analysis, both parties will pre-actively know the financial consequences of delays even before the sign of the contract and in the bid phase (after the completion of design). Therefore, they will schedule project tasks more carefully to minimize the damage. This financial model can lead the contract to have a more fair penalties for delays in it and in this way, future claims can be minimized.

Iran is located an arid and semi-arid region of the world, with an average annual rainfall of less than one-third of the global average. There is lack of water to meet the consumptions in many sectors. The construction of a reservoir on the rivers as an instrument for regulating flow in time and place is one of the ways to deal with the water crisis, , as more than one dam has been built on some rivers. Functional dependence and the impact of the operation of each reservoir on the other one leads to the complexity of the operation of multi reservoir systems. In reservoir operation models, various requirements, such as agriculture, drinking, environmental and hydropower is considered. Multi-objective optimization models are an appropriate tool for dealing with heterogeneous multi-objective problems. MOPSO and NSGA-II are effective multi-objective optimization models that have been considered by many researchers so far. In this research, the comparison of two widely used NSGA-II and MOPSO algorithms to extract the rule curves of Boostan and Golestan reservoirs located in Gorgan Rood watershed in drought conditions has been investigated.

Dam behavior investigation has been considered for a long time, with many studies conducted to identify and predict factors influencing such structures. In common dynamic analyses of dams, an input acceleration is typically used. At the same time, it was proved that such structures with a large contact with the ground usually experience different accelerations in their various supporting points. Applying different accelerations on different supports of a structure can increase their stresses and displacements. The stresses can be among factors affecting dam stability. Thus, it is very important to accurately study its effect on the dynamic behavior of arc concrete dams. Furthermore, in most arc dam analyses, their bodies have been treated as integrated, while such dams are constructed by putting together concrete blocks with vertical joints in practice. In the current study, after building an ABAQUS three-dimensional model of Karoon-4 Dam as the tallest arc concrete dam in Iran, it was attempted to apply the vertical joints to compare the dynamic behavior of arc concrete dams under uniform and non-uniform analyses and the case in which the dam body is modeled in an integrated form. The results revealed that the non-uniform analysis increased  stresses and displacement of  dam.....

The stability of a gravity dam on a jointed rock foundation might be endangered by weak joints that may be present in the fracture network of the bed rock. A review of the literature shows that there are few studies of the effect of a weak joint in the foundation rock on the stability of dams. This research uses the finite difference numerical modelling software ABAQUS to model a gravity dam, the foundation rock, and the influence of a weak joint (using interfaces), that exist in the bottom of dam with different direction, on the stability of the dam. To do this, a conceptual model has been developed and one representative joint of a discrete fracture network with seven different dip angle was examined. Thses different varying dip angles were studied in order to investigate the critical configuration that has the most significant effect on the dam’s stability.As a case study, Pine Flate dam, is modeled with the ABAQUS software as a two-dimensional and Nonlinear dynamic analysis is done by implicit method with applying vertical and horizontal components of the El-Centro earthquake. The obtained results show that existness of joint in the foundation significantly affected the dynamic responcse of dam.