Pullout Performance of Inclined Helical Screw Anchors in Sand
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 124, Issue 7
Abstract
Experimental and theoretical studies on the pullout performance of inclined helical screw anchors are presented. Previous contributions are reviewed and compared. The experimental program was conducted on anchors inclined at 15, 30, and 45° with respect to the vertical and installed into dense, medium, and loose sands. Special tests on anchors inclined at 45 and 60° installed into colored-layered sands were conducted to define the failure mechanism and the associated rupture surface. The results of these tests confirmed that the rupture surface is unsymmetrical and of a very complex nature; however, it can be represented by segments of logarithmic spiral curves. These segments differ in shape and size along the anchor perimeter. The concept of a conjugate anchor and auxiliary rupture surface was developed and introduced to correlate the pullout capacities of inclined and vertical anchors installed to the same depth in identical sand conditions. A coefficient of embedment depth was established and expressed theoretically in terms of the relative depth and the angle of inclination to facilitate the calculation of the pullout capacity of inclined anchors. A comparison of theoretical and experimental as well as field results showed reasonable agreement and confirmed the validity of the proposed theory.
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References
1.
Das, B. M., and Seeley, G. R.(1975). “Inclined load resistance of anchors in sand.”J. Geotech. Engrg. Div., ASCE, 101(9), 995–998.
2.
Frydman, S., and Shaham, I.(1989). “Pullout capacity of slab anchors in sand.”Can. Geotech. J., Ottawa, Canada, 26(3), 385–400.
3.
Getzeler, Z., Komornik, A., and Mazurik, A.(1968). “Model study on arching above buried structures.”J. Soil Mech. and Found. Div., ASCE, 94(5), 1123–1141.
4.
Ghaly, A. M. (1990). “Performance of single screw anchors and group action in sand,” PhD thesis, Concordia Univ., Montreal, Canada.
5.
Ghaly, A. M., and Hanna, A. M.(1992). “Stresses and strains around helical screw anchors in sands.”J. Soils and Found., JSSMFE, 32(4), 27–42.
6.
Ghaly, A. M., and Hanna, A. M.(1994). “Ultimate pullout resistance of vertical anchors.”Can. Geotech. J., Ottawa, Canada, 31(5), 661–672.
7.
Hanna, A. M., Das, B., and Foriero, A. (1988). “Behavior of shallow inclined plate anchors in sand.”Proc., Spec. Topics in Found., Braja M. Das, ed., ASCE, Reston, Va., 54–72.
8.
Hanna, A. M., and Ghaly, A. M.(1992). “Effects of K0 and overconsolidation on uplift capacity.”J. Geotech. Engrg., ASCE, 118(9), 1499–1469.
9.
Harvey, R. C., and Burley, E.(1973). “Behaviour of shallow inclined anchorages in cohesionless sand.”Ground Engrg., London, England, 6(5), 48–55.
10.
Kulhawy, F. H. (1985). “Uplift behavior of shallow soil anchors—An overview.”Proc., Uplift Behavior of Anchor Found. in Soil, Samuel P. Clemence, ed., ASCE, Reston, Va., 1–25.
11.
Larnach, W. J., and McMullan, D. J. (1974). “Behaviour of inclined groups of plate anchors in dry sand.”Proc., Conf. Inst. of Civ. Engrg., London, England, 153–156.
12.
Meyerhof, G. G. (1973). “Uplift resistance of inclined anchors and piles.”Proc., 8th Int. Conf. on Soil Mech. and Found. Engrg., 2.1, 167–172.
13.
Radhakrishna, H. S. (1976). “Helix anchor tests in sand—Essa T. S.”Res. Rep. No. 76-130-K, Ontario Hydro. Res. Div., Ontario, Canada.
14.
Riemann, G. F. B. (1953). The collected works of Bernhard Riemann, Heinrich Weber, ed., Dover Publications, Inc., New York, N.Y., Chap. I, 3–36 (in German).
15.
Robinson, K. E., and Taylor, H.(1969). “Selection and performance of anchors for guyed transmission towers.”Can. Geotech. J., Ottawa, Canada, 6(2), 119–137.
16.
Spiegel, M. R. (1964). Theory and problems of complex variables with an introduction to conformal mapping and its applications. Schaum Publishing Co., New York, N.Y., Chap. 8, 200–231.
17.
Sutherland, H. B., Finlay, T. W., and Fadl, M. O.(1983). “Uplift capacity of embedded anchors in sand.”Proc., Int. Conf. on the Behaviour of Off-shore Structures, 3, 451–463.
18.
Tran, V. N. (1971). “Ultimate uplift capacity of anchor piles.”Proc., 4th Budapest Conf. on Soil Mech. and Found. Engrg., Akadémiai Kiodó, Budapest, Hungary, 589–600.
19.
Trofimenkov, J. G., and Mariupolskii, L. G.(1965). “Screw piles used for mast and tower foundations.”Proc., 6th Int. Conf. on Soil Mech. and Found. Engrg., Univ. of Toronto Press, Toronto, Canada, 2, 328–332.
20.
Vesic, A. S.(1971). “Breakout resistance of objects embedded in ocean bottom.”J. Soil Mech. and Found. Div., ASCE, 97(9), 1183–1205.
21.
Wang, M. C., and Wu, A. H. (1980). “Yielding load of anchor in sand.”Proc., Application of Plasticity and Generalized Stress-Strain in Geotech. Engrg., R. N. Young and E. T. Selig, eds., ASCE, Reston, Va., 291–307.
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Copyright © 1998 American Society of Civil Engineers.
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Published online: Jul 1, 1998
Published in print: Jul 1998
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