Mosul and Haditha Dams are the two largest dams of Iraq. They were constructed in localities having completely different materials for use in the core and rip-rap. While clay for the core was abundant in Mosul Dam site it was completely missing in the other dam site. Where solid and sound limestone for the rip-rap was available in large quantities in Mosul dam only dolomitic limestone of inferior quality was there in Haditha Dam site. In Haditha Dam, the use of the only available material for the core was mealy dolomite and it was used successfully, but the addition of an asphaltic concrete diaphragm was necessary to improve impermeability of this core. The use of this material for the first time in the world was a challenging task to the engineers, who could not have done this without carrying out first comprehensive field and laboratory research. Even sand and gravel materials were available in the two sites in ways that borrowing and using them required completely different techniques in the two sites. In the shells of Mosul Dam, they were placed and compacted after minimum treatment, filter material; however, had to be sorted out and mixed in screening plants. In Haditha Dam site dredging of the materials from the river channel resulted in adopting a hydraulic filling procedure in building the shells and eliminating the filter zones. Good quality limestone was used in Mosul Dam rip-rap but the missing of such rock quality in Haditha Dam dictated the use of concrete facing protection placed by mechanical means. The different construction materials used in the two dams resulted in producing two contrasting designs which had also required different methods of construction and to some extent different machinery. In Mosul Dam, everything followed the standard and classical methods and specifications. In Haditha Dam new specifications were necessary for many items of the work. In both cases, the engineers were successful in producing good designs which were safe and functional.
Keywords: Mosul Dam, Haditha Dam, Clay, Mealy Dolomite, Diaphragm, Hydraulic Fill
ISSN: 1792-9040 (Print)