Journal of Hydraulic StructuresJournal of Hydraulic Structures
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Feed provided by Journal of Hydraulic Structures. Click to visit.Investigating the vulnerability downstream area of Taleghan dam due to dam failure
http://jhs.scu.ac.ir/article_13435_1613.html
Due to the immense damage caused by dam failure, especially dams constructed near large cities, it is necessary to consider the breaking phenomena as well as studying and designing different parts of the dam. For this purpose, the hydrograph of the outflow due to dam failure must be identified according to size of the fracture and then flood routing, and flood zone must be determined based on the downstream topography and morphology. The integration of hydraulic models and geographic information system is used to achieve this objective. In this research the effect of breaking Taleghan storage dam due to the slip of a pile of reservoir abutment and the creation of current wave toward the dam body as well as the vulnerability analysis due to the breaking of the dam on downstream lands was studied. At first, Taleghan dam failure for five different scenarios was modeled using the FLOW-3D numerical software and then the geometric data of the river was extracted using the ArcGIS software and modeling the flood due to dam failure was conducted in Hec-GeoRas model. Then, the risk analysis was performed for each break scenario of Taleghan dam. The results indicated that the maximum amount of inundation would occur in Razmian city at an approximate distance of 45 kilometers from Taleghan dam site.Thu, 30 Nov 2017 20:30:00 +0100An experimental study on hydraulic behavior of free-surface radial flow in coarse-grained ...
http://jhs.scu.ac.ir/article_13436_1613.html
The equations of fluids in porous media are very useful in designing the rockfill and diversion dams, gabions, breakwaters and ground water reserves. Researches have been showed that the Forchheimer equation is not sufficient for the analysis of hydraulic behavior of free-surface radial flows; because, in these flows, in addition to the hydraulic gradient and velocity, the variable of radius is also an independent parameter due to variations in cross section. In this paper, we have used an experimental model to analyze the nonlinear free surface radial flows and to introduce an equation compliant with these flows. This is a semi cylindrical model including a type of coarse grained aggregate which leads the radial flow into the center of a well. Thereafter, the hydraulic gradient was measured on different points of the experimental model by three distinguished methods of difference of successive radii, keeping constant the minimum and maximum radii. An equation, describing the behavior of free surface radial flow, was then proposed by measured data (as regression data) from the laboratory and analysis of the results. Verification of the proposed equation by test data shows that the equation is valid on the established limits of the data.Thu, 30 Nov 2017 20:30:00 +0100Three-dimensional numerical modeling of score hole in rectangular side weir with finite volume ...
http://jhs.scu.ac.ir/article_13437_1613.html
Local scouring in the downstream of hydraulic structures is one of the important issues in river and hydraulic engineering, which involves a lot of costs every year, so the prediction of the rate of scour is important in hydraulic design. Side weirs are the most important of hydraulic structures that are used in passing flow. This study investigate the scouring due to falling jet from side weir in downstream in side channel numerically. The simulation was done with finite volume method. The comparison of numerical and experimental results of flow fields shows agreement. Results show that from upstream to downstream of side weir located in side channel, scoring is increased and the dimensions of the scour hole in the downstream of the rectangular side weirs increase along it. In fact, at the downstream of the lower edge of side weirs in side channel, scouring has the greatest dimensions; in particular the depth.Thu, 30 Nov 2017 20:30:00 +0100Experimental Study of the Effect of Base-level fall at the Beginning of the Bend on Reduction ...
http://jhs.scu.ac.ir/article_13461_1613.html
Base-level fall in river beds occurs due to varying natural or unnatural causes. Base-level fall causes the change in the behavior of flow at the location of drop in base-level. In such situations, most of scour occur at the foot of the slope, and slope wall retreats in the upstream direction. This phenomenon widens the wall of the river bank, thus leading to its destruction. The amount of bed topography variations and scour around a rectangular bridge pier with an oblong nose located in the 90 degree angle of a 180 degree sharp bend was studied in this work by generating base-level fall at the beginning of the 180 degree sharp bend, and it was compared with a case without a base-level fall. The results indicated that in the case of base-level fall at the upstream side of the bridge pier, increase in flow depth, as well as reduction in velocity at the area around the pier, is observed, and the maximum depth of scour hole and the volume of scour hole around the pier respectively reduce by 73 and 97% in comparison with those in the case where no base-level fall occurs.Thu, 30 Nov 2017 20:30:00 +0100