Failure mechanism; Finite-difference analysis; Interfering footings; Kinematical element method; Limit analysis; Limit equilibrium; Element method; Geotechnical Engineering and Engineering Geology; Environmental Science (all); General Environmental Science
Résumé :
[en] In this paper, the ultimate bearing capacity of two closely spaced rigid strip footings with rough base on granular soil is examined based on enhanced limit equilibrium, plastic limit analyses, and finite-difference solutions. The enhanced limit equilibrium and plastic limit analyses are developed on the basis of two proposed failure mechanisms in association with an optimization algorithm. The limit analysis is conducted by using the kinematic element method (KEM), and finite-difference package is used for numerical simulations. The efficiency factors of bearing capacity are calculated at various spacings between two neighboring footings for practical range of friction angles (25° ≤ ϕ ≤ 40°) in accordance with different solutions. Thereafter, the results obtained from the proposed solutions are compared with those reported from existing experimental, theoretical, and numerical studies. In addition, the reliability of the proposed mechanisms is justified through a series of comparisons with the failure patterns and the shear bands obtained from numerical simulations at different spacings. These comparisons indicated that despite the relative simplicity of proposed solutions, bearing capacities and failure patterns are in excellent accordance with numerical, analytical, and experimental results.
Disciplines :
Ingénierie civile
Auteur, co-auteur :
ALIMARDANI LAVASAN, Arash ; University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Engineering (DoE)
Ghazavi, Mahmoud; Faculty of Civil Engineering, K.N. Toosi Univ. of Technology, Tehran, Iran
von Blumenthal, Achim; Ruhr-Universität Bochum, Bochum, Germany
Bolton, M. D., and Lau, C. K. (1993). "Vertical bearing capacity factors for circular and strip footings on Mohr-Coulomb soil." Can. Geotech. J., 30(6), 1024-1033.
BSI (British Standards Institution). (1995). "Geotechnical design. I: General rules (together with the United Kingdom National Application Document)." DD ENV 1997-1:1995-Eurocode 7, Elsevier, Amsterdam, Netherlands.
Chen, W. F. (1975). Limit analysis and soil plasticity, J. Ross Publishing, Plantation, FL.
Das, B. M. (1999). Shallow foundations: Bearing capacity and settlement, CSR Press, Boca Raton, FL.
Das, B. M., and Larbi-Cherif, S. (1983). "Bearing capacity of two closely spaced shallow foundations on sand." Soils Found., 23(1), 1-7.
Dewaikar, D. M., and Mohapatro, B. G. (2003). "Computation of bearing capacity factor Nγ-Terzaghi's mechanism." Int. J. Geomech., 3(1), 123-128.
Frydman, S., and Burd, H. J. (1997). "Numerical studies of bearing capacity factor Nγ." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE) 1090-0241(1997)123:1(20), 20-29.
Ghazavi, M., and Lavasan, A. A. (2008). "Interference effect of shallow foundations constructed on sand reinforced with geosynthetics." Geotext. Geomembr., 26(5), 404-415.
Gussmann, P. (1982). "Kinematical elements for soils and rocks." Proc., Int. Conf. on Numerical Methods in Geomechanics, A.A. Balkema, Rotterdam, Netherlands, 47-52.
Gussmann, P. (1986). Die Methode der kinematischen Elemente [Kinematical elements method], Institut für Grundbau und Bodenmechanik, Stuttgart, Germany.
Gussmann, P. (2000). "Effective KEM solutions for the limit load and the slope stability problem." Int. J. Numer. Anal. Methods Geomech., 24(14), 1061-1077.
Hanna, T. H. (1963). "Model studies of foundation groups in sand." Geotechnique, 13(4), 334-351.
Hansen, J. B. (1970). "A revised and extended formula for bearing capacity." Geoteknisk Inst. Bull., 28, 5-11.
Harr, M. E. (1966). Foundations of theoretical soil mechanics, McGraw- Hill, New York.
Hazell, E. C. J. (2004). "Interaction of closely spaced strip footings." Final Year Project Rep., Univ. of Oxford, Oxford, U.K.
Hjiaj, M., Lyamin, A. V., and Sloan, S. W. (2005). "Numerical limit analysis solutions for the bearing capacity factor Nγ." Int. J. Solids Struct., 42(5), 1681-1704.
Kennedy, J., and Eberhart, R. (1995). "Particle swarm optimization." Proc., Int. Conf. on Neural Networks, Vol. 4, IEEE, Piscataway, NJ, 1942-1948.
Kumar, A., and Saran, S. (2003). "Closely spaced footings on geogridreinforced sand." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE) 1090-0241(2003)129:7(660), 660-664.
Kumar, J. (2003). "Nγ for rough strip footing using the method of characteristics." Can. Geotech. J., 40(3), 669-674.
Kumar, J., and Bhattacharya, P. (2011). "Bearing capacity of two interfering strip footings from lower bound finite elements limit analysis." Int. J. Numer. Anal. Methods Geomech., 37(5), 441-452.
Kumar, J., and Ghosh, P. (2007). "Ultimate bearing capacity of two interfering rough strip footings." Int. J. Geomech., 10.1061/(ASCE) 1532-3641(2007)7:1(53), 53-62.
Kumar, J., and Khatri, V. N. (2008). "Effect of footing width on Nγ." Can. Geotech. J., 45(12), 1673-1684.
Kumar, J., and Kouzer, K. M. (2007). "Effect of footing roughness on bearing capacity factor Nγ." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE) 1090-0241(2007)133:5(502), 502-511.
Kumar, J., and Kouzer, K.M. (2008). "Ultimate bearing capacity of equally spaced multiple strip footings on cohesionless soils without surcharge." Int. J. Num. Anal. Methods Geomech., 32(3), 251-264.
Lavasan, A. A., and Ghazavi, M. (2008). "Influence of interference on failure mechanism of closely constructed circular footings on reinforced sand." Proc., 4th Asian Conf. on Geosynthetics, Springer, Berlin, 311-317.
Lavasan, A. A., and Ghazavi, M. (2012). "Behavior of closely spaced square and circular footings on reinforced sand." Soils Found., 52(1), 160-167.
Lee, J., and Salgado, R. (2005). "Estimation of bearing capacity of circular footings on sands based on cone penetration test." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE)1090-0241(2005)131:4(442), 442-452.
Lee, J., Salgado, R., and Kim, S. (2005). "Bearing capacity of circular footings under surcharge using state-dependent finite element analysis." Comput. Geotech., 32, 445-457.
Mabrouki, A. D., Benmeddour, R. F., and Mellas, M. (2010). "Numerical study of the bearing capacity for two interfering strip footings on sands." Comput. Geotech., 37(4), 431-439.
Mandel, J. (1965). "Plastic interference of strip footings (in French)." Proc., 6th Int. Conf. Soil Mechanics and Foundation Engineering, Vol. II, University of Toronto Press, Toronto, 127-141.
Martin, C. M. (2005). "Exact bearing capacity calculations using the method of characteristics." Proc., IACMAG, CRC Press, London, 441-450.
Martin, C. M., and Hazell, E. C. J. (2005). "Bearing capacity of parallel strip footings on non-homogeneous clay." Proc., Int. Symp. on Frontiers in Offshore Geotechnics, CRC Press, London, 427-433.
Meyerhof, G. G. (1963). "Some recent research on the bearing capacity of foundations." Can. Geotech. J., 1(1), 16-26.
Michalowski, R. (1997). "An estimate of the influence of soil weight on bearing capacity using limit analysis." Soils Found., 37(4), 57-64.
Potts, D. M. (2003). "Numerical analysis: A virtual dream or practical reality?" Geotechnique, 53(6), 535-573.
Rankine, W. J. M. (1857). "On the mathematical theory of the stability of earthwork and masonry." J. Franklin Inst., 63(2), 84-85.
Silvestri, V. (2003). "A limit equilibrium solution for bearing capacity of strip foundations on sand." Can. Geotech. J., 40(2), 351-361.
Sloan, S. W. (1988). "Lower bound limit analysis using finite elements and linear programming." Int. J. Numer. Anal. Methods Geomech., 12(1), 61-77.
Smith, C. C. (2005). "Complete limiting stress solutions for the bearing capacity of strip footings on a Mohr-Coulomb soil." Géotechnique, 55(8), 607-612.
Soubra, A.-H. (1999). "Upper-bound solutions for bearing capacity of foundations." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE) 1090-0241(1999)125:1(59), 59-68.
Stuart, J. G. (1962). "Interference between foundations with special reference to surface footings in sand." Geotechnique, 12(1), 15-22.
Terzaghi, K. (1943). Theoretical soil mechanics, Wiley, New York.
Ueno, K., Miura, K., Kusakabe, O., and Nishimura, M. (2001). "Reappraisal of size effect of bearing capacity from plastic solution." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE)1090-0241(2001) 127:3(275), 275-281.
Ukritchon, B., Whittle, A. J., and Klangvijit, C. (2003). "Calculations of bearing capacity factor Nγ using numerical limit analyses." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE)1090-0241(2003)129: 6(468), 468-474.
Vakili, K., Lavasan, A. A., Schanz, T., and Datcheva, M. (2014). "The influence of the soil constitutive model on the numerical assessment of mechanized tunneling." Proc., 8th European Conf. on Numerical Methods in Geotechnical Engineering, CRC Press, London, 889-894.
Vesic, A. S. (1973). "Analysis of ultimate loads of shallow foundations." J. Soil Mech. Found. Div., 99(1), 45-73.
Yin, J. H., Wang, Y. J., and Selvadurai, A. P. S. (2001). "Influence of nonassociativity on the bearing capacity of a strip footing." J. Geotech. Geoenviron. Eng., 10.1061/(ASCE)1090-0241(2001)127:11(985), 985-989.
Zhao, C., Lavasan, A. A., Barciaga, T., Zarev, V., Datcheva, M., and Schanz, T. (2015). "Model validation and calibration via back analysis for mechanized tunnel simulations-The Western Scheldt tunnel case." Comput. Geotech., 69, 601-614.
Zhu, D. Y., Lee, C. F., and Jiang, H. D. (2001). "A numerical study of the bearing capacity factor Nγ." Can. Geotech. J., 38(5), 1090-1096.
