Although PLAXIS has its roots in soft soil, it is well equipped for finite element analyses in hard soils and rocks. In addition to dedicated facilities for the modelling of tunnels, rock bolts and field stress conditions, it includes the necessary constitutive models to simulate the behaviour of various types of rock. It is important to note that rock behaviour (even the same rock formation) can vary a lot from one place to another, because of local irregularities.
Geotechnical Earthquake Engineering is a special discipline in our profession. It requires understanding of the terminology and methods that are necessary to safely design structures against earthquakes as well as understanding of the features of soil behaviour under dynamic and cyclic loading, including liquefaction.
Model parameters can be easily obtained from standard site investigation data. A finite element analysis using the Soft Soil model is more accurate and realistic than when using a simple model, at least when dealing with soft soils. And, more importantly, it provides a safe solution when stability is at stake.
The Hardening Soil model is such a model that captures several features of real soil behaviour; both for sandy soils as well as for clays and silts. In this article I will further explain some practical details of the Hardening Soil model with the purpose to take away some fear and encourage you to use this model in your next geotechnical application.
Numerical modelling of geotechnical applications requires appropriate soil models to obtain realistic and accurate results. In this respect, a simplified model like the linear elastic perfectly plastic Mohr-Coulomb model can be regarded as inappropriate, since it lacks important features of real soil behaviour. If you are still addicted to Mohr-Coulomb, it’s time to move on. In this blog I will explain why, and what are the better alternatives.
Bentley PLAXIS includes many advanced material models besides Hooke’s law of isotropic elasticity and Mohr-Coulomb. This blog discusses the material models in PLAXIS 2D, PLAXIS 3D.