Title: 1300-Ton-Capacity Prestressed Anchors Stabilize Dam
Date: August, 1965
Volume: 10
Issue: 4
Page number: 18-36
Author(s): A. Eberhardt, J. A. Veltrop
https://doi.org/10.15554/pcij.08011965.18.36

Click here to access the full journal article

Abstract

The Wanapum hydro power station on the Columbia River provides for ten installed and six future generating units. To reduce initial outlay, construction of the monoliths for these six units was limited  to the intakes. The intakes, however, lacked stability. Tying them down to the rock foundation with prestressed anchors was a practical and most economical solution. Thirteen anchors, each of nearly  1300-ton capacity and 70 feet deep, were required for each monolith, using the conventional 45 0 wedge theory. Although contract drawings showed details of the anchors, bidders- were allowed to  submit their own designs and stressing methods. The contractor proposed the BBRV system. In view of the importance of the - structures and the large capacity of the anchors, a full-scale field pull-out  test was required and performed successfully. Each anchor consisted of 4 cables, each cable containing 90 1/4-inch-diameter parallel high-strength steel wires with button head ends and anchor heads of  the BBRV type. The bottom 30 feet of the cable were grouted before stressing. The work was completed successfully and at a lower cost than estimated. The non-linear elastic effects observed during the  pull-out test were identified as characteristics of the steel wire and not as a possible increase in the effective length of the cables due to rock deformation or anchor slippage.

References

1. Timoshenko, S. and Goodier, J. N., Theory of Elasticity, Second Edition, McGraw-Hill, New York, 1951.

2. Guyon, Y., Prestressed Concrete,  Fourth Edition, John Wiley & Sons, New York, 1960.

3. Leonhardt, F., Spannbeton fur die Praxis, Wilhelm Ernst & Son, Berlin, 1955.

4. Lin, T. Y., Design of Prestressed Concrete Structures, John Wiley & Sons,  New York, 1955.

5. Ross, "Hume Dam-Rock Anchor", Transfer of Stressing Force (Unpublished  Report).

6. Ross, "Augmentation of Hume Weir", Strengthening of Concrete Dam by Means of BBRV Rock Anchors Preliminary Design Computations (Unpublished Report).

7. Timoshenko, S., Strength of Materials, Vol. II-Advanced Theory and Problems, Third Edition, D. Van Nostrand Co., Inc., New York, 1956, p. 411 ff.

8. Zienkiewicz, O. C. and Gerstner, R. W., "Stress Analysis and Special Problems of Prestressed Dams", Journal of the Power Division, ASCE, January 1961.

9. Morris, S. S. and Garrett, W. C., "The Raising and Strengthening of Steenbras  Dam", Transactions of the South African Institute of Civil Engineers, Vol. 5, No. 10, October 1955.

10. Wilkins, J. K. and Fidler, J., "Design of Catagunya Prestressed Dam", Civil  Engineering Transactions, The Institution of Engineers, Australia, September 1959.

11. T. V. A., Johnsonville Steam Plant, "Pull-out Test of Anchor Cells in Chert", December 6, 1949.

12. Engstrom, U. V., "Innovations at Wanapum", Civil Engineering, October 1963.

13. Eberhardt, A and Veltrop, J. A., "Prestressed Cable Anchorage for a Large  Tainter Gate", Submitted for publicationto ASCE.