Shur River Dam, Sar Cheshmeh, Iran

National Iranian Copper Industries Co. (NICICO)

2007 - 2010

Situation

The Shur River Dam was initially proposed as an integral component of the upgrade of the tailings and water management system for the Sar Cheshmeh Copper Mine. The upgrade included the integration of 12 x 24m diameter Paste Thickeners.

The Shur River Dam is now the main site for the storage of process water from the mine and it’s design has been situated such that overflow from the thickeners would gravitate to the storage. Decant return from the tailings storage facility can also be pumped into this storage on an as required basis.

Solution

An initial study of options was undertaken by ATC Williams to enable a recommendation on the embankment type required to be made. Five alternative embankment types were short-listed following the study:

  • Concrete Faced Rock-Fill (CFRD)
  • Geomembrane Faced Rock-Fill (GMRD)
  • Asphaltic Concrete Core Rock-Fill (ACRD)
  • Earth Core Rock-Fill (ECRD) and
  • Roller Compacted Concrete (RCCD)

The selection of the embankment type required for the Shur River Dam site was based on a number of factors, including:

  • Availability of suitable construction materials
  • Foundation conditions
  • The ability to store water during the construction period
  • Robustness in the event of overtopping during construction
  • Availability of in-country construction expertise with respect to the proposed embankment types
  • Potential for flooding of downstream toe from the development of the tailings beach
  • Local climatology
  • Overall cost

After assessment of all of the available information, an asphaltic concrete core rock-fill dam was chosen as the most appropriate and cost effective solution for this site. This decision was attributable to two significant factors: Firstly the low quantities of available suitable clay soils at the site and secondly, the potential requirement for the embankment to store water during the construction period.

As the Dam is located in an extreme seismic region, detailed seismic analysis was undertaken utilising the finite element analysis software, FLAC.

Ultimately, the final design included a cross valley embankment with a height of 80m and a 35m high saddle embankment, with a combined crest length of 660m. The total storage capacity at Full Supply Level is 34,000Ml.

Features on this unique design include: Stream diversion structures (12m high clay core coffer dam and 1500mm diameter through-embankment pipe), a pontoon mounted return water pump and pipe system and extensive curtain grouting of the rock foundation to a depth of 40m.

The Hazard category for this dam, in accordance with ANCOLD Guidelines, is ‘High C’.