Practical Subgrade Model for Improved Soil-Structure Interaction Analysis: Software Implementation
Publication: Practice Periodical on Structural Design and Construction
Volume 15, Issue 4
Abstract
Subgrade models are relatively simple and easy-to-use approximations of the actual load-displacement behavior of the ground and have always played a significant role in foundation engineering research and practice. Winkler’s Hypothesis has been used almost exclusively for this purpose even though it has long been recognized as providing a poor approximation of actual subgrade behavior. The primary flaw of Winkler’s Hypothesis is the lack of coupling or connection between adjacent subgrade “springs.” Although numerous subgrade models that inherently incorporate “spring coupling” into their mathematical formulation have been developed, none has seen widespread adoption and use to date. This is due primarily to various issues that hinder their use with the commercially available structural analysis software used in routine practice. This paper is the second in a series of three that collectively illustrate the development and implementation of a new hybrid subgrade model with inherent spring coupling called the Modified Kerr/Reissner (MK/R) model. The MK/R model has been developed specifically to be both relatively easy to implement using commercially available structural analysis software as well as to evaluate using conventional geotechnical site-characterization methodologies. This particular paper is devoted to practical guidance as to how this is accomplished.
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Acknowledgments
The ANSYS (version 11.0) software and computer hardware on which it was installed that were used for analyses involving the MK/R model were provided by the first author’s employer, URS Energy and Construction Division. This support is acknowledged with gratitude. The use of software trade names in this paper is for necessary identification purposes only and does not necessarily constitute a recommendation or endorsement of that software by the authors or their employers.
References
ACI Committee 336. (1988). “Suggested analysis and design procedures for combined footings and mats.” ACI Struct. J., 85(3), 304–324.
ACI Committee 336. (1989). “Closure to ‘Suggested analysis and design procedures for combined footings and mats’.” ACI Struct. J., 86(1), 113–116.
Banavalkar, P. V. (1995). “Mat foundation and its interaction with the superstructure.” Design and performance of mat foundations; state-of-the-art review, E. J. Ulrich, ed., ACI, Detroit, 13–49.
Berardi, R., and Lancellotta, R. (1991). “Stiffness of granular soils from field performance.” Geotechnique, 41(1), 149–157.
Bowles, J. E. (1986). “Mat design.” ACI J., 83(6), 1010–1017.
Bowles, J. E. (1988). Foundation analysis and design, 4th Ed., McGraw-Hill, New York.
Burland, J. B., Broms, B. B., and De Mello, V. F. B. (1977). “Behaviour of foundations and structures.” Proc., 9th Int. Conf. on Soil Mechanics and Foundation Engineering, Japanese Society of Soil Mechanics and Foundation Engineering, Tokyo, 495–546.
Burland, J. B., and Burbridge, M. C. (1985). “Settlement of foundations on sand and gravel.” Proc.-Inst. Civ. Eng., 78, 1325–1381.
Charles, J. A. (1996). “The depth of influence of loaded areas.” Geotechnique, 46(1), 51–61.
Horvath, J. S. (1979). “A study of analytical methods for determining the response of mat foundations to static loads.” Ph.D. dissertation, Polytechnic Institute of New York, Brooklyn, N.Y.
Horvath, J. S. (1983). “New subgrade model applied to mat foundations.” J. Geotech. Engrg., 109(12), 1567–1587.
Horvath, J. S. (1984). “Simplified elastic continuum applied to the laterally loaded pile problem—Part 1: Theory.” Laterally loaded deep foundations: Analysis and performance—STP 835, E. T. Mosley and C. D. Thompson, eds., ASTM, Philadelphia, 112–121.
Horvath, J. S. (1988). “Historical review and critique of mathematical models for plate- and beam-type foundation element subgrades.” Rep. No. CE/GE-88-4, Dept. of Civil Engineering, School of Engineering, Manhattan College, Bronx, N.Y.
Horvath, J. S. (1989). “Subgrade models for soil-structure interaction.” Proc., Foundation Engineering Congress, ASCE, New York, 599–612.
Horvath, J. S. (1993a). “Subgrade modeling for soil-structure interaction analysis of horizontal foundation elements.” ASCE Metropolitan Section Structural and Geotechnical Groups Joint Meeting, ASCE, New York.
Horvath, J. S. (1993b). “Subgrade modeling for soil-structure interaction analysis of horizontal foundation elements.” Rep. No. CE/GE-93-1, Dept. Civil Engineering, School of Engineering, Manhattan College, Bronx, N.Y.
Horvath, J. S. (2002). “Soil-structure interaction research project: Basic SSI concepts and applications overview.” Rep. No. CGT-20022, Center for Geotechnology, School of Engineering, Manhattan College, Bronx, N.Y.
Horvath, J. S. (2009). SSIH: A computer program for soil-structure interaction analysis of horizontal foundation elements; user instructions and guidelines.
Horvilleur, J. F., and Patel, V. B. (1995). “Mat foundation design—A soil-structure interaction problem.” Design and performance of mat foundations; state-of-the-art review, E. J. Ulrich, ed., ACI, Detroit, 51–94.
The Institution of Structural Engineers. (1989). Soil-structure interaction; the real behaviour of structures, The Institution of Structural Engineers, London.
Liao, S. S. C. (1991). “Estimating the coefficient of subgrade reaction for tunnel design.” Final Draft Rep. for Internal Research Project, Parsons Brinckerhoff, Inc., New York.
Liao, S. S. C. (1995). “Estimating the coefficient of subgrade reaction for plane strain conditions.” Geotech. Eng., 113(3), 166–181.
Lopes, F. R. (2000). “Design of raft foundations on Winkler springs.” Design applications of raft foundations, J. A. Hemsley, ed., Thomas Telford, London, 127–154.
Reissner, E. (1958). “A note on deflections of plates on a viscoelastic foundation.” ASME Trans. J. Appl. Mech., 25, 144–155.
Rhines, W. J. (1965). “Foundation models for continuously supported structures.” Ph.D. dissertation, New York Univ., Bronx, N.Y.
Ulrich, E. J. (1995). “Subgrade reaction in mat foundation design.” Design and performance of mat foundations; state-of-the-art review, E. J. Ulrich, ed., ACI, Detroit, 95–116.
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Information
Published In
Practice Periodical on Structural Design and Construction
Volume 15 • Issue 4 • November 2010
Pages: 278 - 286
Copyright
© 2010 ASCE.
History
Received: Sep 24, 2009
Accepted: Dec 22, 2009
Published online: Oct 15, 2010
Published in print: Nov 2010
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