Yet Another Lesson Learned from Wolf Creek

Wolf Creek Dam is part of the US Army Corps of Engineers (USACE), Nashville District portfolio, located along the Cumberland River in southern Kentucky.

Construction began in 1941, and the reservoir, Lake Cumberland, was impounded in 1952. There was a construction delay of several years (1942 to 1947) due to World War II. The dam is founded on karstic limestone. Wolf Creek Dam has a gravity portion with 37 concrete monoliths, and an embankment portion constructed of well compacted clay.
Seepage was detected by 1962 in the form of significant wet areas along the downstream toe. Two sinkholes were discovered in 1968, both on downstream area adjacent to the powerhouse switchyard, and muddy show in tailrace.

Several remediation contracts were performed from 1975 to 1979 to include a series of grout curtains and a diaphragm wall constructed by ICOS. The ICOS wall was constructed at the crest of the dam along the upstream shoulder of US Route 127.

There have been several lessons learned regarding the ICOS wall of Wolf Creek Dam, probably the most famous lesson was foreseen by Ralph Peck who stated that the first barrier wall was neither long enough nor was it deep enough.

This lesson learned technical paper will discuss the features of construction allowed to remain in place after completion of ICOS diaphragm wall project. The features were located right of the interface of the embankment and gravity portions of the dam along the crest. They were paved over with bituminous hot mix. Due to increasing traffic loads on US Route 127, settlement, rutting and cracking occurred and were documented and described in several annual inspections, periodic assessment reports and numerous dam safety incident reports. Cracks, rutting, and differential settlement were observed in the roadway at the crest along both north and south bound lanes. Some of the problem areas were understood. However, the cause and full extent were not revealed until the design of the remediation began in 2016 and historical construction documents were discovered and reviewed.

This technical paper will tell the story and communicate the lessons learned.