Cherokee and Douglas Dams | USA
Project summary
Images of the project
Cherokee and Douglas Dams
At the end of 2013, the TVA (Tennessee Valley Authority) provided specifications for the construction monitoring of both the Cherokee and Douglas Dam Renovation Projects in Tennessee. The concrete dams were built in the 1940s and needed to be updated to more current standards to withstand a 1000-year flood.
In order to withstand this type of event, the design called for the installation of rock anchors into the concrete blocks in both the spillway and non-overflow zones for the Cherokee Dam and the Douglas Dam. This construction project also included raised flood walls.
Monitoring the Cherokee and Douglas Dams
Sixense, Inc. was contracted in 2014 to provide deformation monitoring during structural modifications due to their long-standing expertise in the industry.
During the rock anchor tensioning portion of the project, monitoring was required for the relative movement between the concrete blocks. The monitoring called for a precision of 1/16” to ensure any potential movement caused by the construction activity could be controlled at a safe level.
High Precision Requirements
The primary challenge of the monitoring task was the demand for high precision. Initially, a manual survey solution was considered. However, an Automated Motorized Total Station (AMTS) alternative was proposed by Sixense and accepted by the TVA.
The AMTS system provided a near real-time monitoring solution for both dams during construction, delivering structural movement data with 1-3 mm precision at measuring distances of 100-120 meters.
Project Completion
Sixense Northern America completed their monitoring work for the historical dams in 2014. For six months, they were able to mitigate the risk of failure during the construction work and implement a successful monitoring system on the Cherokee and Douglas Dams.
