Discover how a tailor-made workflow shortened the repetitive task of suction pile analysis for Technip Energies, and opened up a wider use of PLAXIS 3D in the earlier stages of a project’s feasibility and design. This new tool can deliver faster and more accurate results, with less expense, and less demand on engineers’ time.
For many construction projects, the sheer number of design calculations can seem overwhelming, and the degree of effort and time required to do them underappreciated.
“It always takes longer than you think,” confesses François Coste, Geotechnical Department Manager of the Onshore-Offshore Engineering Division of Technip Energies. “This kind of numerical analysis often seems to be not so complex or complicated when you start to the do calculation, but ahhh, later….”
It was the possibility of condensing that lengthy process that led Technip Energies and Seequent to explore a new way of using PLAXIS 3D; a shorter, swifter, automated workflow that could lift the burden of repetitive calculations on suction pile analysis, save the time of senior engineers, and potentially reduce costs.
Putting PLAXIS 3D’s versatility to work
Technip Energies were in the first stages of examining a floating offshore wind farm project, and had established that there were nearly 600 anchors to design, including numerous sub models. Each had complex and varied anchor geometry, and the task would be a significant draw on expert time.
PLAXIS 3D can be invaluable in carrying out advanced numerical analysis in the later stages of a scheme, where fine detail is imperative. It’s frequently used this way. However, it’s less often applied at the early concept stage – where Technip Energies needed help – even when it could be useful in determining design feasibility, and delivering a more accurate estimate of costs.
The reason? While PLAXIS 3D is both powerful and comprehensive, the complex geometry problems it solves often require an expert hand at the tiller. That’s something usually reserved for the Detailed Design stage of a scheme, and beyond the more time and budget limits of the concept stages.
PLAXIS is an accomplished solution that comes with many options and choices, says François. But these choices normally need a senior engineer to rationalise and sift their way through. Was there a way of simplifying and automating the suction pile analysis workflow so it could be safely passed down to a junior engineer to complete.
Working with Seequent’s Richard Witasse (Principal Application Engineer, Geotechnical Analysis), they began to develop and evaluate an answer, explains François.
Displacement contour plot under service load.
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“Together we simplified the modelling so that something that was previously only achievable by an expert is now doable by a junior engineer. But the quality remains the same, and it’s quick and easy for an expert to validate what the junior has done – that’s a very important advantage of this solution.”
The tool is faster – “on a big project it can save a lot of time and expense” – and while it was originally developed to take the computational sting out of very large and complex schemes, Technip Energies have come to apply it to smaller ones too. “Even on a very small project it can make a difference,” notes François. “Perhaps the time saving is less important, but it still delivers an extra level of quality and frees your experts to focus on other areas. It simplifies, it makes things more consistent, and it gains you time.”
After all, points out François “it’s always the same kind of calculations you’re doing; always the same kind of numerical analysis; always the same kind of results.” So to have a more expensive senior engineer carrying out this repetitive works not only adds to the cost but can slow a project down.
By providing juniors with a clear, automated path that bypasses those unneeded options, this suction pile analysis workflow can help prevent errors, ensure consistent, computational efficiency, and reduce manual effort.
Solving the problem of limited feasibility budgets
Importantly this means it does become economically viable to bring PLAXIS 3D in at the earlier stages of a project, even with a limited budget, confirms François.
Feasibility and costing studies can therefore be carried out more quickly, in greater depth and with more accuracy. It can also help to avoid the over-conservative pre-design calculations that companies settle on as a safeguard. Further down the line, those calculations can not only introduce technical and operational issues but also inflate costs unnecessarily. In turn that can make companies less competitive, and their engineering potentially less efficient, increasing the risk of being less profitable, or ultimately, losing pitches altogether.
Most relevant results for geotechnical design.
Python scripting enables other companies to do the same
The automation process is driven by the PLAXIS Python scripting interface, with a simple input file that contains key parameters such as the geometry dimensions of the suction pile, load values and application points, and soil stratigraphy, including associated stiffness and strength parameters.
“This project with François and the Technip Energies team really demonstrates what’s possible when deep engineering expertise meets targeted automation,” says Richard Witasse, Principal Application Engineer at Seequent. “By collaborating closely, we were able to identify bottlenecks and build a robust tool that’s now replicable in other contexts too. This isn’t just for suction piles—it’s a reusable approach to making PLAXIS 3D more scalable across many types of geotechnical workflows.”
“Indeed, the key factor for the success of this tool was the close cooperation between us and Seequent,” concludes Francois. “It has opened up many possibilities for us as a company, to be able to perform this kind of study, this kind of complex calculation at an earlier stage… It is part of our mindset, our ‘démarche’. We are always trying to improve ourselves, to be more competitive, and with this tool Seequent has helped us do that.”
How it works
Simplified input file for automatic PLAXIS 3D model generation.
Four ways the PLAXIS 3D suction pile script simplifies the workflow, while still arriving at detailed and accurate results.
Model Generation and Optimisation
The script dynamically sets up the PLAXIS 3D model based on the provided input data, ensuring an optimised representation of the suction pile and surrounding soil. It takes care of:
- Automatic dimension scaling to balance accuracy and computational cost
- Optimised meshing, refining key areas while maintaining efficiency
- Phase definitions, handling both drained and undrained analyses depending on soil conditions and project requirements
Push-Over Analysis and Failure Envelope Calculation
To assess the ultimate capacity of the suction pile, the script implements a push-over analysis using the yield loci probe technique, which enables:
- Automatic determination of the necessary number of push-over analyses to define the failure envelope
- Systematic variation of load directions to generate the interaction diagram
Post-Processing of Key Results
Once the simulations are complete, the script extracts and processes the most relevant results, including:
- Load-displacement curves to evaluate pile performance
- Failure envelope (interaction diagram) to characterize load-bearing capacity
- Deformed mesh visualisation to assess soil-structure interaction
- Soil pressure distribution on the suction pile to analyse load transfer mechanisms
Computational Efficiency Considerations
The automation framework is designed to maximize computational efficiency by:
- Adjusting solver settings and numerical parameters for optimal performance
- Selecting appropriate load step controls and phase sequences to minimize run times
- Ensuring robust convergence across different loading conditions
By integrating these elements, this solution provides a streamlined, repeatable, and computationally efficient approach to suction pile analysis in PLAXIS 3D, making it ideal for both research and engineering applications.