Related Links
Laboratory study of the effect of submersible jumping in reducing scouring downstream of stilling basin (Case study: masonary check dam of Ziarat) | ||
| تحقیقات مهندسی سازه های آبیاری و زهکشی | ||
| Volume 22, Issue 84, November 2021, Pages 69-88 PDF (964.59 K) | ||
| Document Type: Original Article | ||
| DOI: 10.22092/idser.2021.355937.1486 | ||
| Authors | ||
| mohammad ali solbi1; mehdi meftah halaghi* 2; Amir Ahmad Dehghani3; abdolreza zahiri4 | ||
| 1Gorgan University of Agricultural Sciences and Natural Resources, | ||
| 2Associated professor, Water Eng. Department of water and soil Eng., Gorgan university of agricultural science and natural resources, Gorgan, Iran | ||
| 3Associate Professor of Water Structures, Gorgan University of Agricultural -Sciences and Natural Resources | ||
| 4Water Eng. Department, Soil & Water faculty, gorgan Associate Professor of Civil Engineering, Gorgan University of Agricultural Sciences and Natural Resourcesuniversity of agricultural sciences and natural resources | ||
| Abstract | ||
| Abstr Abstract Introduction Masonry check dams are small structures that are built to reduce the slope of the canal, reduce the flow velocity as well as control bed erosion. The distinguishing feature of Masonary check dam and other similar structures is the presence of pipes in the body of check dams. This adds to the complexity of the hydraulic conditions of these structures. As the flow overflows through the Masonry check dams, only some of the kinetic energy of the flow is dissipated in the stilling basin and the excess kinetic energy is occurred downstream of the structure. This situation can cause erosion of the riverbed downstream of the structure. Various methods are designed and implemented to control this excess energy. These methods include changing the height of the bottom bed, roughening the bed and creating a protrusion at the end of the stilling basin in order to create a submerged hydraulic jump into the stilling basin. Due to the fact that the stilling basin used in the main structure is USBR type 1 and in this type of basins, no baffles or end sills are used to dissipate the flow kinetic energy, embedding a sill at the end of the stilling basin is one of the innovations of this research. Also, using a physical model of mortar stone dams has not been reported anywhere and hence, this is also one of the innovations of this research. Therefore, using the physical model of "Tol Beneh" mortar rock dam can help to better understand the impact of scour reduction methods in the main structure constructed on the Gorgan Ziarat River and similar structures Materials and Methods in order to identify scour in Masonary check dam and its control methods, a physical model with a scale of 1:20 was developed. The flow rate in all tests was 25 l/s At first First, experiments were performed to determine the amount of scouring at the stilling basin. The results of these experiments were used to compare with the remaining test conditions. In the second series of experiments, to create a rough bed, the 54 cm long distance (equal to the length of the stilling basin) was covered with materials with a median diameter of 2.5 cm. three heights of 3, 6 and 9cm were used to model the increase of bed elevation (third series experiments). In the fourth series of experiments, to create a sill at the end of the stilling basin, a plastic blade 3 cm high was used in four stages. In the first stage, only a 3 cm sill was installed at the end of the stilling basin. In the second stage, the height of the bed bottom increased by 3 cm along the length of 54 cm. It should be noted that the average diameter of bed particles in these two methods was 4.5 mm. In the third stage, the roughness thickness of the bed materials increased to an average diameter of 2.5 cm without increasing the bed height. In the fourth stage, in addition to increasing the roughness of the bed material, the height of the bed also increased by 3 cm along the length of 54 cm. Results and Discussion In the stilling basin model, the scour depth was 130 mm without any obstacles. In other words, this magnitude represents a scour of 2.60 meter in the prototype. The presence of the end edge at the end of the stilling basin as well as raising the end of the channel causes a submerged hydraulic jump and consequently reduces scouring. If it is used in combination with these two methods, the effect will be greater. The results show that the presence of the end edge at the end of the calm pool shows a greater scouring reduction than increasing the height of the bottom, Keywords: scouring, stilling basin immersion, masonry check dam, stilling basin | ||
| Keywords | ||
| scouring; stilling basin immersion; masonry check dam; stilling | ||
| References | ||
|
Abbasi, A., A., (2015), Field study of the effect of appropriate choice of slope limit in reducing the cost of construction of breeding dams, Journal of Watershed Engineering and Management, 7,(1), 109-115. (in Persian)
Alipour, M, H Ghahari, Gh, R, & Mesbah, S, M, (2019), Stability analysis of stone-mortar dams of Shiraz Cleist watershed. Journal of Watershed Management Research, 32(2), 95-110.
Anon. (2005). Standard publication: No. 34, Publications of the Management and Planning Organization of the country, Fild Methods for Measurment of Rivers and Dam Reserviors Sediment
Anon. (2011). Standard publication: No. 549, Vice President for Strategic Planning and Supervision, Guideline for Estimation of Local Scour
Dilrooban, Y., Imasalan, K., Sujana, K. and Pathirana, K.P.P. (2014). Effect of Bed Roughness on Submerged Hydraulic Jumps. Engineer, XLVII(4), 33-39
Ead, S. A., & Rajaratnam, N. (2002). Plane turbulent wall jets in shallow tailwater. Journal of engineering mechanics, 128(2), 143-155.
Grass, A. J., (1970), The initial instability of fine sand.Proc. ASCE. 96(3):619- 632.
Hong, S. H., Kim, S. J., Sturm, T., &. Stoesser, T., 2010, Effect of low tailwater during drought on scour conditions downstream of an ogee spillway, River flow, (2014) 1193-1199
hydraulic jump downstream of sluice gates”. In Proceeding of 9th Iranian Hydraulics Conference, Tehran, Iran. (in Persian)
Kells, J.A., Balachandar, R., & Hagel, K.P., 2001, Effect of grain size on local channel scour below a sluice gate, Canadianan Jornal of Civil Engineering, 28, (3) 440- 451
Kouchak, P., Shafaei Bajestan, M., (2012), Investigation of changes in the length of downstream scouring of rough horizontal floor dam, 9th International Seminar on River Engineering, February 24, 2013, Shahid Chamran University, Ahvaz. Iran. (in Persian)
Lenzi, M.A. and F. Comiti, 2003. Local scouring and morphological adjustments in steep channels with check-dam sequences, Geomorphologhy, 55(1-4): 97-109
Long, D., P. Steffler and N. Rajaratnam 1990 LDA study of flow structure in submerged hydraulic jump, Journal of Hydraulic Research 28(4): 437-460.
Moradi, A., Parish, Y., (2011), Evaluation of scouring phenomenon in the downstream of overflows and strategies to rehabilitate and reduce scouring, Fourth National Conference on Rehabilitation and Preservation of Permanent Buildings, 15, to 16 October, Islamic Azad University, Khomein Branch, Khomein. Iran. (in Persian)
Nasrabadi, M., Omid, M.H. & Farhoudi, J. (2010). “Comparative study of free and submerged
Omidi, P., Shafaei Bajestan, M., Shokrian, Manouchehr., (2014), The effect of jump position on the overflow on the topography of the downstream bed of the type 1 tranquility pond, 15th Civil Students Conference, September 11-13, Urmia University, Urmia. Iran. (in Persian)
Omidi, S., Shafaei Bajestan, M., (2014), Downstream scouring depth of type 1 pond in free and submerged jump conditions, 13th Iranian Hydraulic Conference, November 12, University of Tabriz, Tabriz. Iran. (in Persian)
Subhasish, D. and Bernhard, W. (2003). Hydraulics of Submerged Jet Subject to Change in Cohesive bed Geometry. Journal of Hydraulic Engineering, 129, 44 - 53.
Valizadegan, A. &, Farhoudi, J., (2002), Control of scouring downstream of calm ponds using stone cutting, Sixth International Seminar on River Engineering, 8 to 10 February, Shahid Chamran University of Ahvaz, Ahvaz. Iran. (in Persian)
Yalin M. S. (1971). Theory of Hydraulic Models, New York, MacMillan
YüKSEL, Y., Günal, M., Bostan, T., Ҫevik, E., and Ҫelikoǧlu, Y. 2004. The Influence of Impinging Jets on Hydraulic Jumps. Process of the Institution of Civil Engineering, Water Management. 157: WM2. 63-76.
Zare Bidaki, & R., Ghanbari, A., (2015), Evaluation of group efficiency of breeding dams using hierarchical analysis process, Iranian Journal of Watershed Management Science and Engineering, 9(28), 1-10. (in Persian) | ||
|
Statistics Article View: 249 PDF Download: 216 |
||
Journal management system. designed by sinaweb