A Study of the conditions of non- sedimentation in Karkhe Inverted Siphon by using a Laboratory Model

Subject Areas : Irrigation and Drainage

حسین خزیمه نژاد ^{1 *} , محمود شفاعی بجستان ²

1 - دانشگاه شهید چمران اهواز، گروه سازه‌های آبی.
2 - دانشگاه شهید چمران اهواز، گروه سازه‌های آبی.

Received: 2011-09-11 Accepted : 2011-11-19 Published : 2633-02-20

Keywords: مدل فیزیکی, Physical model, non sedimentation conditions, Karkhe inverted siphon, شرایط غیر رسوب‌گذار, سیفون معکوس کرخه,

Abstract :

Deposition of sediment inside the conduit structures reduces the flow cross section area and increases the flow roughness which causes reduction of flow discharge passing through the conduit. Among the methods which can prevent sediment deposition is non sedimentation condition in the structure, Since the critical section of the inverted siphon in sedimentation is the outlet. In the begining of this research, a general relationship for conditions of incipient motion that is minimum of non sedimentation in the outlet of Karkhe inverted siphon was developed by applying the dimensional analysis. Then experimental tests were conducted by using physical model and 5 non-cohesive sediment with dimensions of 0.5, 0.7, 1, 2 and 3.2 mm and one graphs was drown that can be used for determining non-sedimentation in outlet conduit of Karkhe inverted siphon. Then, by using this graph and suspended load particle size distribution curves of the Karkheh River in Hamidiyeh diversion dam, minimum non sedimentation velocity was extracted for prevent sediment particle diameter of 1.5 mm that is the largest particle size input to upstream channel of Karkhe inverted siphon from Hamidiyeh diversion dam, were determined. The results show there is a non-sedimentation condition in the Karkheh inverted siphon in designed discharge and velocity

References:

- شفاعی بجستان، م. (1387). مبانی نظری و عملی هیدرولیک انتقال رسوب. انتشارات دانشگاه شهید چمران اهواز. ویرایش دوم.

- سازمان آب و برق خوزستان. (1383). طرح شبکه­ی آبیاری و زهکشی دشت­های پای­پل. مطالعات مرحله­ی دوم. جلد پنجم. گزارش سیمای طرح.

- سازمان آب و برق خوزستان. (1371). طرح آبیاری و زهکشی کرخه. مطالعات مرحله­ی اول. گزارش هیدرولوژی.

- May, R.W.P. (2003). preventing sediment deposition in inverted sewer siphons. Journal of Hydraulic Engineering. ASCE. April, pp. 283-290.

-May, R.W.P. Ackers, C.J. Butler, D. and John s. (1996). Development of design methodology for self-cleansing. wat. sci. tech. vol 33. No 9, pp. 195–205.

- Nalluri, C., Ghani, A.b. (1996). Design options for Self-cleansing storm  sewers. wat. sci. tech. vol 33. No 9, pp. 215–220.

- Nalluri, C. Spaliviero, P. (1998). Suspended sediment transport in rigid boundary channels at limit deposition. wat. sci. tech. vol 37. No 1, pp. 147–154.

- Shafai Bejestan, M. (1990). Critical stability number in rock lined channels. Iran Agricultural Research. vol 9. Shiraz university, pp. 121-138.