Remedial Treatment Exploration, Wolf Creek Dam, Ky.

After 15 years of apparently satisfactory operation, Wolf Creek Dam developed underseepage and piping problems associated with its karstic foundation. When a sinkhole developed at the downstream toe of the earth embankment, a concentrated program of exploration was undertaken to determine both the source of the problem and possible remedial treatment. Various exploratory techniques were used; however, direct subsurface information obtained by drilling and grouting was the only method reliable enough to define the problem so that a remedy could be devised. After successful emergency grouting had arrested the piping, in all probability saving the dam from a major failure, a search for a permanent answer determined that a concrete diaphragm wall through the earth embankment into the limestone foundation would be the most acceptable method of correcting the problem. Construction of such a wall is costly; therefore, it was important to ascertain the minimal depth and extent required for it. The exploratory methods used for this purpose are reviewed in this paper.