Expert studies on the Dareh Rud river basin began in 1989 and following the approval of the subsequent reports, projects for the construction of a dam in that region were drawn up in 1993. In continuation of these studies, consultant engineers began studies on the first and second phases of Sabalan and its marshlands in 1994 and 1996 respectively.
Work on the diversion system began in 1996, simultaneously with the start of studies on the second phases, and continued until January 2000.
The Khatamul-Anbia construction headquarters (Ashura institute) began construction work on the dam in June 2001. This work was completed by the end of 2005. The dam became operational in July 2006.

Project’s geographical location
The Sabalan Dam is situated 55 km to the northwest of the city of Ardebil and 40 km to the northeast of Meshkin Shahr.

Project objectives
The objective behind the construction of the Sabalan Dam is to store 105 million cubic metres of water and the regulation of some 115 million cubic of the Farsu river’s irregular water flow, the irrigation of 15,000 hectares of Meshkin Shahr’s agricultural land on both sides of the river, the supply of up to 10 million cubic metres of drinking water to Meshkin Shahr per year until 2021, controlling floods and the creation of employment opportunities and a reduction in migration.

General specification of project
The Sabalan Dam project consists of the following three main parts:
A) A rockfill dam with a clay core with a height of 77 metres from the bed of the Qarsu River and 89 metres from the foundation. The dam crest is 304 metres long and 12 metres wide.
B) The transfer system from the dam to the marshlands consists of four 1700-metre-long tunnels and a 140-metre-long flushes, and four 400-metres galleries between the tunnels.
C) A 44.5 km drainage and irrigation network for the downstream agricultural lands consisting of two main 22.5-km channels in the southern network (on the left shore) and a 22-km northern network (on the right shore)

Other project specifications
Flood water discharge system: A spillway with a 116.40 metre cross section with a discharge rate of 2877 cubic metres per second and a five metre floodgate. Irrigation system: A water intake tower and water extraction tunnel. Water diversion system: Two 4.5 and 5.5 metre diameter tunnels.

A summary of the geological and geotechnical specifications of the Sabalan Dam reservoir, axis and site

A study of the results of the geological studies show that there are two sedimentary and stone units in the dam site and axis. The alluvium at the dam site differentiates between 4.7-8.5 metres and usually is made up of thick particles. The shortage of small particles has resulted in the sedimentary section becoming low in terms of tackiness and sedimentary. This has resulted in the sedimentary section having unsuitable engineering specifications.
Most of the dam site is made up of metamorphic rocks which have been formed as a result of outer weathering cycles and are levelled with an average thickness of 25 metre per each cycle and are deposited towards the west. On the dam axis, there are 3 bulges resulting from igneous cycles and two other cycles have been found during excavation work. The further up we go the less resistant the rock becomes and the amount of weathering increases. On the whole, andosite layers of the studied section have good physical properties.

It’s noteworthy that with thee installation of precision tools, the maximum subsidence of the dam’s core after 5 months of being filled is 112 cm and the maximum subsidence rate of the rock body after five months is 92 cm.

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Reporter : mehdi akbarsefat

َApproved by : Story Id 28

Create date : 19 Dec 2007 14:51

Id : 734

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