Materials: Soil

Description

Soil material is available for 2D plain strain, axisymmetric and 3D analysis. The following soil models are available for these analysis types:

  1. The Duncan-Chang Soil model is widely used for the modelling of soil as a nonlinear material. This model, as one of the first models used in finite element analysis, has been shown valid in a range of practical applications. Two fundamental relations used in the Duncan-Chang model are the Mohr-Coulomb failure criterion and the hyperbolic stress-strain relation.
  2. The Modified Cam-Clay Soil model is a widely used plasticity model. The model includes features such as pressure sensitivity, shear induced dilatancy and hardening/softening responses which are in good agreement with experimental observations. The advantage of this model is that it requires relatively few parameters, which can be obtained from conventional laboratory tests.
  3. The Mohr-Coulomb Soil model is a generalised form of the Coulomb friction failure law which considers additional effects from the water content, void ratio, and in-situ stresses. This soil material model is usually easy to define because of the availability of its parameters.
  4. The Drucker-Prager Soil model is an approximation to the Mohr-Coulomb Soil model which also considers additional effects from the water content, void ratio, and in-situ stresses. This soil material model is usually easy to define because of the availability of its parameters.
  5. The Linear Elastic Soil model is an isotropic soil material that never yields. It does consider the effects of water content, void ratio, and in-situ stresses, so it is useful in conjunction with other soil materials in a finite element model. This model requires the least number of material parameters.

Below are some notes regarding the application of soil material models:

See Results Interpretation: Result Quantities for a description of available soil results quantities.

See the Straus7 Theoretical Manual for more information.

Literature

Duncan, J.M. & Chang, C.Y. 1970, "Nonlinear Analysis of Stress and Strain in Soils," Journal of the Soil Mechanics and Foundations Division, ASCE, vol. 96, no. SM5, September.

Zienkiwicz, O.C. & Taylor, R.L. 1991, The Finite Element Method, 4th ed., vol. 2, McGraw-Hill, London.

Kondner, R.L. 1963, "Hyperbolic stress-strain response: cohesive soils", Journal of Soil Mechanics and Foundations Division, ASCE, vol. 89, no. SM1, February.

Kondner, R.L. & Zelasko, J.S. 1963, "A hyperbolic stress-strain formulation for sands", Proceedings 2nd Pan-American Conference on Soil Mechanics and Foundations Engineering, Brazil, vol. 1, pp 289-324.

Duncan, J.M., Byrne, P., Wong, K.S. and Mabry, P. 1980, Strength, stress-strain and bulk modulus parameters for finite element Analysis of stresses and movements in soil masses, report No. UCB/GT/80-01, University of California, Berkeley, California.

Naylor, D.J., Pande, G.N., Simpson, B. & Tabb, R. 1981, Finite Elements in Geotechnical Engineering, Prineridge Press, Swansea.

Yetimoglu, T., Wu, J.T.H. & Saglamer, A. 1994, "Bearing Capacity of Rectangular Footings on Geogrid-Reinforced Sand", Journal of Geotechnical Engineering, ASCE, vol. 120, no. 12, December.

See Also