Intro to Post-Tensioned Anchors for Dams: Agenda
  • History of Usage in North America
    • Anchors have been used in dams in North America since the early 1960’s. Since then, over 500 projects have been found, and details will be provided on the annual usage rates. The influence of all successive phases of the PTI Recommendations on practice will be illustrated, with special reference to corrosion protection.
  • Best Practices
    • Design: Current anchor design principles will be reviewed (note, this will not address overall system design, just individual component design.)
    • Construction: drilling, water testing, tendon preparation, and installation, and grouting will be discussed.
    • Stressing and Testing: the conduct and analysis of stressing operations will be presented, with a justification for using Performance Tests (as opposed to Proof Tests) for all dam anchors. Acceptability criteria will be reviewed.
  • Long Term Performance Assessment
    • This is arguably the most contentious and worrisome aspect of anchor technology. Insight will be provided on the problems facing the monitoring of “legacy” anchors (i.e., those originally constructed with fully bonded free lengths, and inadequate corrosion protection.) Guidance will be provided on portfolio risk assessment programs, which are becoming more critical as anchors on many projects are now far in excess of their original design lives.
  • Biographical Note
    • The author has been active in rock anchor technology since 1973, as a contractor, designer, and researcher. He is the Co-Principal Investigator (with John S.Wolfhope, of Freese & Nichols Inc.) of the National Research Program on Dam Anchors, and most recently on the related CEATI research project. He has previously given many presentations on anchors at ASDSO events.
Special thanks to our sustaining members