The project consisted of a 480-ft high concrete gravity structure; main spillway with four radial gated bays and six low-level sluices, an uncontrolled emergency spillway, a three-unit, 225-kW powerhouse, and a low-level Howell Bunger valve on the right abutment.
As part of this work, Hatch updated the earlier FEA to include stress-dependent concrete growth effects and enhanced creep. The finite-element model was calibrated to survey data, extensometer measurement, slot cut response, stress cells and overcoring stress measurements.
The results of the analysis were used to make recommendations in life extension of the structure and future remedial action.
In Task 2 of a multi-year contract with TVA, Hatch assessed the condition of the Fontana Dam.
The objective of the project was to evaluate the stability of the dam and to predict the future behavior of the concrete structures affected by concrete growth and develop proposed mitigation options.
The work included:
- Review previous analyses/evaluations
- Review instrumentation data
- Recommend finite element enhancements
- Calibrate finite elements using current data
- Analyze various slot schemes
- Predict long-term concrete growth effects and stability assessment
- Recommendations for rehabilitation and life extension.
Hatch used the finite element program ANSYS to analyze the effects of concrete growth. ANSYS was modified by Hatch to include the stress-dependent nature of concrete growth and enhanced creep effects. The ANSYS finite element program is used to investigate various slot arrangements in the dam and the results will be used to evaluate the dam stability and rehabilitation requirements.
