Numerical Simulation of Vertical Pullout of Plate Anchors in Clay
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 134, Issue 6
Abstract
The behavior of strip and circular plate anchors during vertical pullout in uniform and normally consolidated clays was studied in this paper by means of small strain and large deformation finite-element analyses. Both fully bonded (attached), and “vented” (no suction on rear face), anchors were considered. The current numerical results were compared with existing laboratory test data, finite-element results, and analytical solutions. This study showed that, in small strain analysis, the scatter of existing data was mainly due to the effect of soil stiffness. In large deformation analysis, when soil and anchor base were attached with suction, the pullout capacity factor formed a unique curve independent of the soil strength , soil effective unit weight and anchor size ( =width of strip anchor and =diameter of circular anchor). The transitional embedment depth ratio, or , (where =transition depth between shallow and deep embedment) was 1.4 for a strip anchor and 0.75 for a circular anchor. The ultimate pullout capacity factors for deep embedment were 11.6 and 11.7 for smooth and rough strip anchors and 13.1 and 13.7 for smooth and rough circular anchors, respectively. However, when the anchor base was vented, the soil stayed attached to the anchor base for deep embedment, and the pullout capacity was therefore the same as for the attached anchor. The separation depth ratio, or , (where =embedment depth at which the soil and anchor base separated) was found to increase linearly with the normalized strength ratio, or / .
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Acknowledgments
The research presented here was supported by the Australian Research Council (ARC) through the Discovery Project Scheme (DP0344019). This support is gratefully acknowledged. Experiments could not have been performed without the support of the Centre for Offshore Foundation Systems (COFS), established under the ARC’s Research Centres Program and currently supported as a Centre of Excellence by the State of Western Australia.
References
Benson, D. J. (1989). “An efficient, accurate, simple ale method for nonlinear finite-element programs.” Comput. Methods Appl. Mech. Eng., 72(3), 305–350.
Bransby, M. F., and O’Neill, M. P. (1999). “Drag anchor fluke-soil interaction in clays.” Int. Symp. on Numerical Models in Geomechanics - NUMOG VII, Balkema, Rotterdam, The Netherlands, 489–494.
Carter, J. P., and Balaam, N. (1990). AFENA users manual, Geotechnical Research Centre, The University of Sydney, Sydney, Australia.
Das, B. M. (1978). “Model tests for uplift capacity of foundations in clay.” Soils Found., 18(2), 17–24.
Das, B. M. (1980). “A procedure for estimation of ultimate capacity of foundations in clay.” Soils Found., 20(1), 77–82.
Das, B. M., Shin, E. C., Dass, R. N., and Omar, M. T. (1994). “Suction force below plate anchors in soft clay.” Mar. Georesources and Geotechnology, 12(1), 71–81.
Ehlers, C. J., Young, A. G., and Chen, J. H. (2004). “Technology assessment of deepwater anchors.” Proc., Annual Offshore Technology Conf., Paper OTC 16840.
Elkhatib, S., and Randolph, M. F. (2005). “The effect of friction on the performance of drag-in plate anchors.” Proc., 1st Int. Symp. on Frontiers in Offshore Geotechnics (ISFOG), Taylor and Francis, Rotterdam, The Netherlands, 171–177.
Ghosh, S., and Kikuchi, N. (1991). “An arbitrary Lagrangian-Eulerian finite-element method for large deformation analysis of elasticviscoplastic solid.” Comput. Methods Appl. Mech. Eng., 86(2), 127–188.
Herrmann, L. R. (1978). “Finite-element analysis of contact problems.” J. Engrg. Mech. Div., 104(5), 1043–1059.
Hu, Y., and Randolph, M. F. (1998a). “A practical numerical approach for large deformation problems of soil.” Int. J. Numer. Analyt. Meth. Geomech., 22(5), 327–350.
Hu, Y., and Randolph, M. F. (1998b). “H-adaptive FE analysis of elastoplastic nonhomogeneous soil with large deformation.” Comput. Geotech., 23(1), 61–84.
Martin, C. M., and Randolph, M. F. (2001). “Applications of the lower and upper bound theorems of plasticity to collapse of circular foundations.” Proc., 10th Int. Conf. of the International Association for Computer Methods and Advances in Geomechanics, Vol. 2, 1417–1428.
Merifield, R. S., Lyamin, A., Sloan, S. W., and Yu, H. S. (2003). “Three-dimensional lower bound solutions for stability of plate anchors in clay.” J. Geotech. Geoenviron. Eng., 129(3), 243–253.
Merifield, R. S., Sloan, S. W., and Yu, H. S. (2001). “Stability of plate anchors in undrained clay.” Geotechnique, 51(2), 141–153.
Meyerhof, G. G. (1973). “Uplift resistance of inclined anchors and piles.” Proc., 8th Int. Conf. on Soil Mechanics and Foundation Engineering, Moscow, Vol. 2, 167–172.
Meyerhof, G. G., and Adams, J. I. (1968). “The ultimate uplift capacity of foundations.” Can. Geotech. J., 5(4), 225–244.
Rowe, R. K. (1978). “Soil structure interaction analysis and its application to the prediction of anchor behaviour.” Ph.D. thesis. University of Sydney, Sydney, Australia.
Rowe, R. K., and Davis, E. H. (1982). “The behavior of anchor plates in clay.” Geotechnique, 32(1), 9–23.
Turner, D. (2001). “Study of pullout capacity of flat plate anchors in offshore engineering.” Project Rep., Curtin University of Technology, Australia.
Vesic, A. S. (1971). “Breakout resistance of objects embedded in ocean bottom.” J. Soil Mech. and Found. Div., 97(9), 1183–1205.
Yu, H. S. (2000). Cavity expansion methods in geomechanics, Kluwer Academic, Dordrecht, The Netherlands.
Zienkiewicz, O. Z., and Zhu, J. Z. (1992). “The superconvergent patch recovery and a posteriori error estimates. Part 1: The recovery technique.” Int. J. Numer. Methods Eng., 33(7), 1331–1364.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 134 • Issue 6 • June 2008
Pages: 866 - 875
Copyright
© 2008 ASCE.
History
Received: Apr 11, 2007
Accepted: Oct 1, 2007
Published online: Jun 1, 2008
Published in print: Jun 2008
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