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|Title:||Post-tensioned multistrand anchorage capacity deterioration due to corrosion : John Day Lock project|
|Authors:||Ebeling, Robert M., 1954-|
Haskins, Richard W.
Scofield, David H.
Hite, John E.
Strom, Ralph W.
John Day Lock Project
Snake River locks and dams
|Publisher:||Coastal and Hydraulics Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical note (Coastal and Hydraulics Engineering (U.S.)) ; IX-28.|
BACKGROUND: A Research Work Unit (WU) has been initiated in the Navigation Systems Research Program to investigate post-tensioned multistrand anchors. A significant number of COE projects have installed multistrand high-capacity post-tensioned foundation anchors over the last three decades. These anchors are embedded and access is limited to the top anchor head for inspection purposes. Due to the evolution of corrosion protection criteria for ground anchors, the early installed anchors may have inadequate corrosion protection that does not meet current corrosion protection standards. The older anchors are approaching the end of their design life and are showing various degrees of deterioration, corrosion, and broken strands. Current load capacity and remaining life of the anchors are unknown. One procedure used to test post-tensioned tendons involves lift-off tests, which are both dangerous and expensive. The applicability of lift-off testing to most existing ground anchorage is severely restricted to the very few existing ground anchors that were not grouted for corrosion protection along the free length of the anchor and which also have special provisions for the connection of the jacking equipment to the anchor head. This severely restricts the practical use of lift-off testing of existing ground anchorage as a viable testing procedure. Additionally, testing deteriorated anchors has been avoided in the past because of greater danger of breaking anchors. To meet reliability analysis required for major rehabilitation studies, estimates of load capacity, rate of decrease, and remaining life are required.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Technical Note|
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|ERDC-CHL-CHETN-IX-28.pdf||517.92 kB||Adobe PDF|