Epoxy-coated rock anchors for upper Occoquan Dam
- Harza Engineering Co., Chicago, IL (United States)
- Fairfax County Water Authority, VA (United States)
High-capacity, epoxy-coated anchors were installed at Upper Occoquan Dam to increase the stability of the 70-foot-high concrete gravity dam and powerhouse under revised Probable Maximum Flood (PMF) conditions. The post-tensioned anchorage system consisted of 56 multi-strand rock anchors with design loads of 700 to 1855 kips, averaging 1500 kips per tendon. A double corrosion protection system was specified to provide protection throughout the entire anchor length. During anchor stressing and testing, significant creep movement under constant loads equivalent to 133% of the design load was experienced and exceeded the requisite Post-Tensioning Institute (PTI) criteria. In addition to the creep phenomena, seating losses during transfer of the load to the end anchorage are at least 2 to 3 times greater than that which has been experienced with bare-wire strand tendons. On the basis of anchor test results, modifications were made to the anchor testing protocol, acceptance criteria, and the approach used for assessment of the long-term performance of the anchorage system.
- OSTI ID:
- 220208
- Report Number(s):
- CONF-9507190-; TRN: 96:000708-0290
- Resource Relation:
- Conference: Waterpower 1995: international conference, San Francisco, CA (United States), 25-28 Jul 1995; Other Information: PBD: 1995; Related Information: Is Part Of Waterpower`95. Volume 1-3; Cassidy, J.L. [ed.]; PB: 2869 p.
- Country of Publication:
- United States
- Language:
- English
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