ABSTRACT
Ituango Project is the largest hydroelectric development in Colombia, with an installed generation capacity of 2400 MW. The rock mass of interest is located on a lithology corresponding to schistose gneisses. In the main works around thirty kilometers of underground excavation have been constructed. Regarding the infrastructure of the project, twelve road tunnels have been excavated, totalizing around four kilometers of underground excavations. The behavior of the rock mass under construction was predicted by empirical and analytical analysis based on the 8000 m of drills and 2000 m of adits. Despite following the rigorous procedures set by the designers, some problems of falling wedges and convergences occurred, related to the heterogeneity of the rock mass and the normal problems of construction. The purpose of this paper is to report the main problems under construction and describe the causes to the biggest problems occurred during the underground excavation.
