Post-Tensioned Rehabilitation Applied to Hydropower Dams: Continuously Improving on an Anchor Program

As part of a $50 Million modernization program, post-tensioned anchors were used to stabilize four large high-hazard hydropower dams in central Texas, USA. The use of anchors for the rehabilitation of each structure evolved by incorporating lessons learned on the previous dams. The anchoring program was tailored for the unique challenges of each facility. The analysis of the difficult conditions and material quality issues encountered during rehabilitation of the first dam provided an opportunity to improve the stabilization design of the remaining dams. Through the use of extensive field investigations, test anchor programs, and peer review, the post-tensioned anchor details and specifications were progressively improved for each rehabilitation project. This paper discusses the lessons learned installing over 300 anchors on four high-hazard dams and developments made during the anchoring program. Although each application is unique and requires investigation and testing to establish the details and specifications, the model followed in this paper can be applied in response to unique hydropower configurations and site specific challenges to build a successful post-tensioned anchor rehabilitation program.

• Background

• Description of Projects Sites

• Anchor Stabilization Program

• Comparison of Anchor Programs

• Conclusions

• References