ABSTRACT
The utilization of superposed galleries, as a construction procedure to develop a positive cutoff is a not a common practice but in some instances, due to the site conditions and nature of the materials found, conventional treatments are not deemed suitable. Materials with certain consistencies hinder the efficacy of conventional grouting. As an alternative, chemical grouting has sometimes been considered, but later was discarded because of elevated costs and uncertain duration of the work. The last inconvenience is particularly important for the overall construction program of the whole dam, because interferences with other critical activities in the construction process can have a negative effect on the overall duration of the project.
