Abstract:
The Mosul Dam is an earth fill dam built in the first half of the 1980s on the Tigris river, about 60km North of Mosul (Iraq). The foundation rock comprises gypsum, anhydrite, marl, dolomite, and limestone strata. Over the years, the structural integrity of the dam and its operational capacity gave cause for severe concerns, principally because of phenomena of dissolution in water of gypsum and anhydrite layers occurred in the bedrock foundation. In consideration of the critical situation characterizing the dam, in 2015 the Iraqi Government issued an international invitation to tender with an emergency procedure for the maintenance and safety of the dam. Trevi was awarded the tender: the contract included works for the repair of manufactured structures in correspondence of the bottom outlet and grout injections aimed at repairing the grout curtain. Concurrently, the design and the supervision of the works was entrusted to the USACE, acting as Engineer for the project. This paper mainly focuses on the activities and drilling-and-grouting technologies implemented for the refurbishment of the grout curtain, and carried out both form the embankment and from the grouting gallery located at the base of the dam embankment. Keywords: Dam Safety, Grouting, Remediation, Grout Curtain