CS11C - Concurrent Session 11C: Yet Another Lesson Learned from Wolf Creek

The U.S. Army Corps of Engineers (USACE) operates and maintains approximately 740 dams and associated structures nationwide that provide significant, multiple benefits to the nation—its people, businesses, critical infrastructure and the environment. Wolf Creek Dam is part of the 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 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 filled with 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 barrier 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 barrier wall was neither long enough nor was it deep enough.

This lesson learned abstract will discuss the features or elements of construction allowed to remain in place after completion of ICOS wall project. The features were left in place at the interface of the embankment and gravity portions of the dam. 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 and periodic assessment reports. Cracks, rutting, differential settlement were observed in the roadway at crest both north and south bound lanes. Some of the problem areas were understood. However, the cause and full extent were not understood until the design of the fix began in 2016 and historical construction documents were discovered and reviewed.