Constitutive modeling of jointed rock masses has long been a subject of interest and numerous models have been developed in attempts to simulate their mechanical responses. There are two groups of these models: discrete models and continuum models as summarized by Cai and Horii (1993):
The Convergence-Confinement Method is a basic and commonly used tool for underground support structures in conventional tunneling during the preliminary stage of design.
The Rock Your Analysis with PLAXIS series will discuss rock engineering applications, their challenges, and the resources that numerical modelers and geotechnical engineers can use to solve these problems by using PLAXIS geotechnical analysis software.
In both analytical and numerical approaches, a significant increment in anchor block pullout capacity was observed after considering the 3D effects over those capacities obtained by considering 2D analysis. As a result, this helps in avoiding underestimation of an anchor block’s pullout capacity and thereby aids in the optimization of anchor block design. In addition, it was promising to note that pullout capacities obtained after considering the 3D effects from both approaches are very close in their magnitudes.
The aim of this article is to demonstrate the suitability of 2D FEM analyses in metro station outer boxes structural element design (even in demanding conditions) with specific reference to the Arlozorov West Station and Rabin Station.
Le Port de Tanger est constitué de caissons en béton armé posés sur un remblai en fond de mer. Les terrains d’assise sont des sables silteux à graveleux épais d’une trentaine de mètres reposant sur le substratum.
“Some projects are 3D in nature and, therefore, require 3D designs to provide appropriate, safe & value-engineering solutions. Hence, PLAXIS 3D is a game-changing tool that helped us to secure such projects.”
In the context of model calibration and validation, conducting a sensitivity analysis is very important. This can determine the key factors which govern the system and efficiently characterize the geotechnical variability for any considered design problem.
The more elements a mesh contains, the larger the stiffness matrix of the system (that needs to be inverted) and the longer the calculation time will be. It is therefore very important to define the optimal model dimension and even more crucial to introduce an appropriate level of mesh refinement, and only where it really matters.