Soil-structure interaction is a crucial aspect for both geotechnical and structural fields. There is always an interaction between a structure and its foundation … and its proper investigation is an important design aspect which should not be neglected. PLAXIS offers extensive modeling features to model structures and the interaction between the structures and the soil.
Geotechnical engineers usually prefer to carry out 2D numerical analyses because FE models are simpler and faster to set up, plus, they are also quicker to run and post-process. On the other hand, 2D models will never fully reflect the true 3D reality of the problem at stake and might often lead to overly conservative results. However, 3D models are more accurate and realistic, but could represent a significantly larger time investment.
Geotechnical applications often involve structures and other objects that interact with the surrounding soil. Although soil behaviour is generally more critical and complex than that of embedded structures, it is important that structures are modelled with the same accuracy as the soil.
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.