MSE walls design in Plaxis

Hi Leo, and welcome to the forum!

When considering the most appropriate soil model for the analysis, several factors need to be taken into account to ensure the safety, stability, and performance of the wall system.

MSE walls are complex structures that require careful design and analysis, incorporating the properties of the reinforced soil, foundation soil, wall facing elements, and any additional loads or constraints imposed by the project specifics.

Here are some general considerations and advice for choosing a soil model:

1. Understanding Soil Properties: The first step is to thoroughly understand the properties of both the reinforced soil and the foundation soil. This includes parameters such as soil type, density, cohesion, angle of internal friction, permeability, and any variations with depth or location. Soil testing and site investigation reports are crucial at this stage.

2. Selection of Soil Model: The choice of soil model depends on the complexity of the project, the level of accuracy required, and the specific properties of the soil.

Commonly used soil models include:

– Elastic-Perfectly Plastic Models (e.g., Mohr-Coulomb model): Suitable for many conventional MSE wall analyses, providing a balance between simplicity and the ability to predict yield conditions.
– Hardening Soil Models: More advanced, allowing for the simulation of soil stiffness increasing with depth and the effects of soil pre-consolidation. These models can better accommodate the non-linear behavior of soils under different loading conditions.
– Advanced Constitutive Models (e.g., Modified Cam Clay, Drucker-Prager): These are used for more complex analyses, such as when accounting for the anisotropic properties of the soil or the long-term creep under sustained loads.

3. Software and Analysis Type: The choice of soil model is also influenced by the analysis software and the type of analysis you intend to perform (e.g., limit equilibrium, finite element analysis). Different software packages may offer different capabilities for modeling soil behavior, and the complexity of the model you choose should align with the type of analysis you’re conducting.

4. Consideration of External Factors: In addition to soil properties, consider external factors such as surcharge loads, seismic activity, water table variations, and environmental conditions. These factors can significantly influence the performance of MSE walls and should be integrated into the analysis model.

5. Consultation with Experts: Given the complexity and the critical nature of these structures, consulting with geotechnical engineers or experts specialized in soil mechanics and MSE wall design is highly recommended. They can provide valuable insights into the most appropriate models and methodologies for your specific case.

6. Review of Similar Case Studies: Reviewing case studies or literature on similar projects can provide insights into successful practices and methodologies applied in similar contexts. This can be a valuable source of information for decision-making.

It’s essential to approach the selection of a soil model as part of a comprehensive design and analysis process, considering both the technical aspects and the practical implications of the project.

Your final choice should provide a realistic representation of soil behavior under the expected loads and conditions, ensuring the stability and integrity of the MSE wall throughout its intended service life.

If you can share more specific information about the reinforced and foundation soil properties, the height and configuration of the MSE wall, and any particular challenges or constraints of your project, I could provide more targeted advice.

Ignacio