Kerr Dam Spillway Stabilization

Over the nearly 60-year operational history for Kerr Dam, the in situ rock of the river bottom began to show signs of wear immediately downstream of the spillway. This project provided additional stability to its spillway, improving overall dam safety.

The Kerr Dam Spillway Stabilization Project included one pre-production post-tensioned rock anchor on the top of the dam, 48 production post-tensioned anchors across the downstream face of the spillway, and a temporary platform for access to the spillway locations. The high-capacity tendons consist of between 36 and 57 strands each. The access platform spanned the entire 824-foot-wide gated spillway with fabricated members provided by Advantage Steel, a crucial planning element to meet the project’s aggressive schedule needs. The Team also installed specialty instrumentation for long-term facility monitoring and safety.

Overall, the 48-anchor-upgrade consisted of 203,844 linear feet of tensioned strand and added 81,430,800 pounds of force to the spillway structure. In comparison, the total force from the new anchors is roughly the equivalent of 23,000 cubic yards of mass concrete if it were added to the structure.

Beyond the challenges of working on the Neosho River, the general site vicinity exhibits an unusual subsurface condition. The shallow rock formation beneath the dam contains perched natural gas under slight pressure. In addition to passive venting at locations across the local area, crew exposure risk was controlled through detection monitoring and a specialty cuttings-handling system planned for the project.

Completion of the project provided the Grand River Dam Authority means to restore Kerr Dam flood control operations to normal.