The Effect of Mechanical Anisotropy and Heterogeneity of Shear Strength Parameters of Soils on Drained Bearing Capacity of Shallow Foundations
Author
Abstract
Natural formation of soil deposits causes heterogeneity and anisotropy in their strength and stiffness properties. However, most soils in their natural states exhibit some anisotropy with respect to shear strength and heterogeneity with respect to the depth. In this paper, the standard Mohr- Coulomb constitutive law is generalized to anisotropic version in order to consider the effect of cohesion anisotropy of soil. Random field theory coupled with finite difference method was utilized in Monte Carlo simulations with considering the effect of auto-correlation and cross correlation between strength parameters of soil, in order to calculate the bearing capacity of shallow foundation in a strain controlled scheme. The results showed that the bearing capacity of shallow foundation decreases with increasing in variability of strength parameters and increases with increasing in anisotropy ratio.
Keywords
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2. Reddy, A. S., and Srinvasan, R. J., “Bearing Capacity of Footings on Anisotropic Soils”, Journal of the Soil Mechanics and Foundations Division, Vol. 96(SM6), pp. 1967-1986, 1970.
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7. Mayne, P. W., “Stress Anisotropy Effects on Clay Strength”, Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 111, pp. 356-66, 1985.
8. Casagrande, A., and Carrillo, N., “Shear Failure on Anisotropic Materials”, Journal of Boston Society of Civil Engineering, Vol. 31, No. 4, pp. 74-87, 1944.
9. Lo, K. Y., “Stability of Slopes in Anisotropic Soils”, Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 31(SM4), pp. 85-106, 1965.
10. Griffiths, D. V., and Fenton, G. A., “Bearing Capacity of Spatially Random Soil, the Undrained Clay Prandtl Problem Revisited”, Geotechnique, Vol. 51, No. 4, pp. 351-359, 2001.
11. Cherubini, C., “Reliability Evaluation of Shallow Foundation Bearing Capacity on c', φ' Soils”, Canadian Geotechnical Journal, Vol. 37, No. 1, pp. 264-269, 2000.
12. Vanmarcke, E., “Reliability of Earth Slopes”, Journal of the Geotechnical Engineering Division, ASCE, Vol. 103, No. 11, pp. 1247-1265, 1971.
13. Soulie, M., Montes, P., and Silvestri, V., “Modeling Spatial Variability of Soil Parameters”, Canadian Geotechnical Journal, Vol. 27, No. 5, pp. 617-630, 1990.
14. Phoon, K. K., and Kulhawy, F. H., “Characterization of Geotechnical Variability”, Canadian Geotechnical Journal, Vol. 36, No. 4, pp. 612-624, 1999.
15. Salencon, J., Discussion on the paper “The Effect of Increasing Depth on the Bearing Capacity of Clays by Davis and Booker”, Geotechnique, Vol. 24, No. 3, pp. 449-451, 1974b.
16. Chen, W. F., Limit Analysis and Soil Plasticity, Elsevier Publishing Company, Amsterdam, 1975.
17. Reddy, A. S., and Venkatakrishna Rao, K. N., “Bearing Capacity of Strip Footing on c-φ Soils Exhibiting Anisotropy and Nonhomogeneity in Cohesion”, Soils and Foundations, Vol. 22, No. 1, pp. 49-60, 1982.
18. Fenton, G. A, and Griffiths, D. V., “Bearing Capacity Prediction of Spatially Random c - φ Soils”, Canadian Geotechnical Journal, Vol. 40, No. 1, pp. 54-65, 2003.
2. Reddy, A. S., and Srinvasan, R. J., “Bearing Capacity of Footings on Anisotropic Soils”, Journal of the Soil Mechanics and Foundations Division, Vol. 96(SM6), pp. 1967-1986, 1970.
3. Salencon, J. “Bearing Capacity of a Footing on φ=0 Soil with Linearly Varying Shear Strength”, Geotechnique, Vol. 24, No. 3, pp. 443-446, 1974a.
4. Salencon, J., Florentin, P., and Gabriel, Y., “Capacite Portante Globalendune Foundation Sur un Sol Nonhomogene”, Geotechnique, Vol. 26, No. 2, 351-370, 1976.
5. Meyerhof, G. G., “Bearing Capacity of Anisotropic Cohesionless Soils”, Canadian Geotechnical Journal, Vol. 15, No. 4, pp. 592-595, 1978.
6. Duncan, J. M., and Seed, H. B., “Anisotropy and Stress Reorientation in Clay”, Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 92(SM5), pp. 21-50, 1966.
7. Mayne, P. W., “Stress Anisotropy Effects on Clay Strength”, Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 111, pp. 356-66, 1985.
8. Casagrande, A., and Carrillo, N., “Shear Failure on Anisotropic Materials”, Journal of Boston Society of Civil Engineering, Vol. 31, No. 4, pp. 74-87, 1944.
9. Lo, K. Y., “Stability of Slopes in Anisotropic Soils”, Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 31(SM4), pp. 85-106, 1965.
10. Griffiths, D. V., and Fenton, G. A., “Bearing Capacity of Spatially Random Soil, the Undrained Clay Prandtl Problem Revisited”, Geotechnique, Vol. 51, No. 4, pp. 351-359, 2001.
11. Cherubini, C., “Reliability Evaluation of Shallow Foundation Bearing Capacity on c', φ' Soils”, Canadian Geotechnical Journal, Vol. 37, No. 1, pp. 264-269, 2000.
12. Vanmarcke, E., “Reliability of Earth Slopes”, Journal of the Geotechnical Engineering Division, ASCE, Vol. 103, No. 11, pp. 1247-1265, 1971.
13. Soulie, M., Montes, P., and Silvestri, V., “Modeling Spatial Variability of Soil Parameters”, Canadian Geotechnical Journal, Vol. 27, No. 5, pp. 617-630, 1990.
14. Phoon, K. K., and Kulhawy, F. H., “Characterization of Geotechnical Variability”, Canadian Geotechnical Journal, Vol. 36, No. 4, pp. 612-624, 1999.
15. Salencon, J., Discussion on the paper “The Effect of Increasing Depth on the Bearing Capacity of Clays by Davis and Booker”, Geotechnique, Vol. 24, No. 3, pp. 449-451, 1974b.
16. Chen, W. F., Limit Analysis and Soil Plasticity, Elsevier Publishing Company, Amsterdam, 1975.
17. Reddy, A. S., and Venkatakrishna Rao, K. N., “Bearing Capacity of Strip Footing on c-φ Soils Exhibiting Anisotropy and Nonhomogeneity in Cohesion”, Soils and Foundations, Vol. 22, No. 1, pp. 49-60, 1982.
18. Fenton, G. A, and Griffiths, D. V., “Bearing Capacity Prediction of Spatially Random c - φ Soils”, Canadian Geotechnical Journal, Vol. 40, No. 1, pp. 54-65, 2003.
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